Method, radio access network node, and user equipment

Abstract

To provide a radio access network node and a method for configuring at least one resource for a victim base station to measure cross-link interference (CLI) caused by a radio transmission from a remote aggressor base station.SOLUTION: In a communication system, a victim base station determines a level of cross link interference (CLI) based on a received signal strength value of a CLI reference signal from a remote aggressor base station. The received signal strength value may be a CLI channel state information reference signal received power value or a base station specific CLI received signal strength indicator value.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to communication systems. [Background technology]

[0002] This disclosure relates to communication systems. The disclosure has particular, but not exclusive, relevance to wireless communication systems and devices thereof operating in accordance with 3rd Generation Partnership Project (3GPP®) standards or equivalents or derivatives thereof (including LTE-Advanced, next generation or 5G networks, future generations, and beyond). The disclosure has particular, but not exclusive, relevance to improved apparatus and methods for managing interference, such as crosslink interference and remote interference, in time division duplex (TDD) communication bands.

[0003] Recent developments in 3GPP standards are referred to as the Long Term Evolution (LTE) of the Evolved Packet Core (EPC) network and the Evolved UMTS Terrestrial Radio Access Network (E-UTRAN), also commonly referred to as "4G." Furthermore, the terms "5G" and new radio (NR) refer to evolving communications technologies that are expected to support a variety of applications and services. Various details of 5G networks are described, for example, in the "NGMN 5G White Paper" V1.0 by the Next Generation Mobile Networks (NGMN) Alliance, available at https: / / www.ngmn.org / 5g-white-paper.html. 3GPP intends to support 5G through the so-called 3GPP Next Generation (NextGen) Radio Access Network (RAN) and 3GPP Next Gen core (NGC) network.

[0004] Under 3GPP standards, a NodeB (or "eNB" in LTE and "gNB" in 5G) is a base station through which communication devices (User Equipment or "UE") connect to the core network and communicate with other communication devices or remote servers. For simplicity, this application uses the terms RAN node or base station to refer to such access nodes.

[0005] For simplicity, this application uses the terms mobile device, user device, or UE to refer to any communication device that can connect to a core network via one or more base stations. While this application may refer to mobile devices in the description, it will be understood that the described techniques can be implemented in any communication device (mobile and / or generally fixed) that can connect to a communication network to transmit and receive data, whether controlled by human input or by software instructions stored in memory.

[0006] Simultaneous transmission and reception between a base station and a user equipment (UE) typically involves the use of different resources for the uplink and downlink. These resources can be different frequencies in the case of frequency division duplex (FDD) or time resources in the case of time division duplex (TDD). While FDD networks use separate uplink and downlink frequency bands, TDD networks use the same bandwidth but allocate different time slots for the uplink and downlink. That is, in FDD, frequency domain resources are divided into downlink (DL) and uplink (UL), while in TDD, time domain resources are divided into DL and UL.

[0007] The appropriate duplexing scheme used in a given scenario, although there may be some overlap, is highly spectrum-dependent. When lower frequency bands are used for communication, paired spectrum is typically allocated for UL and DL resources, and thus FDD is used. In contrast, in higher frequency bands, the use of unpaired spectrum, i.e., TDD, is becoming increasingly prevalent. Therefore, TDD is widely used in commercial NR deployments. Given that the carrier frequencies supported by 5G and future communication generations (6G and beyond) are particularly higher compared to previous communication generations, improved techniques for the efficient use of unpaired spectrum are and will remain increasingly important.

[0008] In a TDD network, so-called cross link interference (CLI) may occur, such as cross link interference between base stations (e.g., between gNBs) or CLI between UEs (intra-UE).

[0009] Inter-gNB CLI may arise from base stations transmitting and receiving on the same frequency band and may take the form of, for example, adjacent channel CLI, co-channel CLI (or both), depending on the deployment scenario.

[0010] Inter-UE CLI includes CLI occurring between UEs in the same cell (intra-cell CLI), for example, as a result of both DL and UL transmissions occurring in parallel. In this scenario, a UE may observe interference in the DL from adjacent subbands used for UL transmissions from other UEs in the same cell. Such interference may be caused, for example, by nonlinear distortion or frequency errors (e.g., Doppler spread in DL reception). The interference is expected to be particularly pronounced in DL frequency resources close to UL resource elements (REs). This can be a serious problem that can reduce system efficiency if interference occurs in DL reference signal (RS) reception (e.g., Channel State Information RS (CSI-RS) reception).

[0011] For FD operation where the subbands do not overlap, both intra-subband and inter-subband CLI may be particularly relevant.

[0012] Another form of CLI is called remote interference. Remote interference occurs when atmospheric conditions cause radio waves from a transmitter (base station) to propagate through the troposphere to distant locations (which can be 300-400 km away), where these waves can interfere with local transmissions. 3GPP has introduced the so-called Remote Interference Management Reference Signal (RIM-RS) to mitigate interference from remote base station downlink signals in cases where atmospheric conditions are favorable for tropospheric polarization of radio waves to occur.

[0013] The typical transmission range of a gNB is several kilometers. However, when tropospheric polarization of radio waves occurs, even if the victim and aggressor base stations are synchronized, the long transmission delay (up to 1.3 ms) of signals from aggressor base stations traveling hundreds of kilometers is highly likely to interfere with the UL reception of the victim base station. This could affect hundreds of base stations.

[0014] The frame structure design in NR already takes into account flexible guard periods (GPs) to leave a large margin for avoiding remote interference, but a mechanism for determining when and for how long a sufficiently long GP should be set needs to be considered.

[0015] 3GPP Technical Report (TR) 38.828 V16.1.0 discusses NR crosslink interference handling and Remote Interference Management (RIM). The document explains that in Release 15, synchronized TDD is expected to support the coexistence of different networks operating on adjacent carriers in the same band. As long as all networks apply the same uplink and downlink timing, interference between adjacent carriers will be mitigated.

[0016] Dynamic TDD refers to an operating mode in which the network adapts the DL / UL subframe pattern according to traffic conditions. When different nodes in the same network apply DL and UL at different times, interference occurs between different UEs and different base stations. 3GPP specifies measurements to mitigate co-channel cross-link interference (CLI) in the same network. Dynamic TDD also causes interference between adjacent channel networks. Unlike the co-channel case, interference between adjacent channel networks cannot be adjusted. Instead, because analog filtering is typically not feasible within the operating band, interference is mitigated by transmitter and receiver selectivity (Adjacent Channel Leakage Power Ratio (ACLR) and Adjacent Channel Selectivity (ACS)).

[0017] A recent Release 16 work item (3GPP RP-193190) discusses further details of crosslink interference handling and remote interference management for NR. A new cell-specific reference signal for RIM (called RIM-RS) is introduced, which uses a triplet of {time, frequency, sequence} to implicitly index the cell ID. There are two types of RIM-RS: the first type is transmitted by the victim node, and the second type is transmitted by the aggressor (through reciprocity). An additional guard period is also provided for RIM.

[0018] Regarding UE-to-UE CLI management, currently proposed approaches rely on sounding reference signals (SRS) for UE-to-UE CLI measurements. The so-called SRS Reference Signal Received Power (SRS-RSRP) has been defined to enhance UE measurements to support CLI management. However, SRS-RSRP is manufacturer-specific, and it is unclear how it can be used to mitigate interference via scheduling and coordination between two base stations.

[0019] Another 3GPP Release 16 work item (3GPP RP-213557) includes a study on the evolution of NR duplexing operation. This document addresses potential enhancements to subband non-overlapping duplexing schemes and dynamic / flexible TDD. It also identifies possible schemes and evaluates their feasibility and performance. The objectives of this work item include studying the handling of inter-gNB and inter-UE CLIs and identifying solutions for managing them, particularly considering intra-subband and inter-subband CLIs in the case of subband non-overlapping full duplex. It also includes studying the performance of the identified schemes as well as their impact on legacy operation where coexistence on co-channels and adjacent channels is expected. Summary of the Invention [Problem to be solved by the invention]

[0020] However, a key issue not addressed in the previous releases or in the 3GPP work items mentioned above is inter-gNB CLI. Specifically, there is no agreement yet on CLI measurement and reporting, gNB coordination mechanisms, and interference mitigation methods.

[0021] It can therefore be seen that there is a need for an enhancement to provide improved CLI handling between base stations (of the same or different operators) and / or between UEs to enable efficient dynamic / flexible TDD in communication networks.

[0022] The present disclosure aims to provide apparatus and methods that at least partially address the above needs and / or problems. [Means for solving the problem]

[0023] According to one aspect, the present disclosure provides a method performed by a radio access network node, the method including identifying an aggressor node as a source of Cross Link Interference (CLI) within a cell of the radio access network node outside a serving area of ​​the aggressor node based on respective configuration information for determining CLI with respect to a plurality of other radio access network nodes.

[0024] According to one aspect, the present disclosure provides a method performed by a radio access network node, the method including transmitting at least one reference signal for measuring cross link interference (CLI) caused by wireless transmissions from the radio access network node outside a serving area of ​​the radio access network node.

[0025] According to one aspect, the present disclosure provides a method performed by a radio access network node, the method including configuring at least one resource for measuring cross link interference (CLI) caused by wireless transmissions from a transmitter outside a serving area of ​​the transmitter, and determining a level of the CLI based on a received signal strength value of a CLI reference signal received from the transmitter through the at least one resource.

[0026] According to one aspect, the present disclosure provides a method performed by a radio access network node, the method including detecting, based on an associated reference signal, an occurrence of Cross Link Interference (CLI) caused by wireless transmissions from another radio access network node outside the serving area of ​​the other radio access network node, and transmitting information indicative of the occurrence of the CLI to a node responsible for CLI management.

[0027] According to one aspect, the present disclosure provides a method performed by a User Equipment (UE), the method including transmitting an uplink signal such that an arrival time of the uplink signal at a radio access network node coincides with an arrival time of a reference signal from another radio access network node for measuring cross link interference (CLI).

[0028] According to one aspect, the present disclosure provides a radio access network node including means (e.g., a memory, a controller, and a transceiver) for identifying an aggressor node as a source of Cross Link Interference (CLI) within a cell of the radio access network node outside the serving area of ​​the aggressor node based on respective configuration information for determining CLI with respect to a plurality of other radio access network nodes.

[0029] According to one aspect, the present disclosure provides a radio access network node including means (e.g., a memory, a controller, and a transceiver) for transmitting at least one reference signal for measuring cross link interference (CLI) caused by wireless transmissions from the radio access network node outside a serving area of ​​the radio access network node.

[0030] According to one aspect, the present disclosure provides a radio access network node comprising: means (e.g., a memory, a controller, and a transceiver) for configuring at least one resource for measuring cross link interference (CLI) caused by wireless transmissions from a transmitter outside the serving area of ​​the transmitter; and means for determining a level of the CLI based on a received signal strength value of a CLI reference signal received from the transmitter through the at least one resource.

[0031] According to one aspect, the present disclosure provides a radio access network node comprising means (e.g., a memory, a controller, and a transceiver) for detecting occurrences of Cross Link Interference (CLI) caused by wireless transmissions from other radio access network nodes outside the serving area of ​​the other radio access network nodes based on associated reference signals, and means for transmitting information indicating the occurrence of the CLI to a node responsible for CLI management.

[0032] According to one aspect, the present disclosure provides a User Equipment (UE) comprising means (e.g., a memory, a controller, and a transceiver) for transmitting an uplink signal such that the arrival time of the uplink signal at a radio access network node coincides with the arrival time of a reference signal from another radio access network node for measuring cross link interference (CLI).

[0033] Aspects of the present disclosure extend to corresponding systems, apparatus, and computer program products, such as a computer-readable storage medium having instructions operable to program a programmable processor to perform the methods described in the above aspects and possibilities or as recited in the claims, and / or to program a computer suitably adapted to provide an apparatus as recited in any of the claims.

[0034] For the sake of ease of understanding for those skilled in the art, the present disclosure will be described in detail in a 3GPP system (5G network), but the principles of the present disclosure may also be applied to other systems.

[0035] The present disclosure is defined by the claims appended hereto. Aspects of the disclosure are as set out in the independent claims. Some optional features are set out in the dependent claims.

[0036] However, each feature disclosed in this specification (which term includes claims) and / or shown in the drawings may be incorporated into the disclosure independently (or in combination) of any other feature disclosed and / or shown. In particular, but not limited to, features of claims dependent on a particular independent claim may be introduced into that independent claim in any combination or individually. [Effects of the Invention]

[0037] The present disclosure aims to provide apparatus and methods that at least partially address the above needs and / or problems. [Brief explanation of the drawings]

[0038] Exemplary embodiments of the present disclosure will now be described by way of example with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 illustrates schematically a telecommunications system (cellular or wireless mobile) in which exemplary embodiments of the present disclosure may be applied. [Figure 2] FIG. 2 is a schematic block diagram of a mobile device forming part of the system shown in FIG. [Figure 3] FIG. 3 is a schematic block diagram of an access network node (eg, a base station) forming part of the system shown in FIG. [Figure 4] FIG. 4 is a schematic block diagram of a core network node forming part of the system shown in FIG. [Figure 5]FIG. 5 illustrates schematically some exemplary embodiments of the present disclosure implemented in the system illustrated in FIG. [Figure 6] FIG. 6 illustrates schematically some exemplary embodiments of the present disclosure implemented in the system illustrated in FIG. [Figure 7] FIG. 7 illustrates schematically some exemplary embodiments of the present disclosure implemented in the system illustrated in FIG. [Figure 8] FIG. 8 illustrates schematically some exemplary embodiments of the present disclosure implemented in the system illustrated in FIG. [Figure 9] FIG. 9 illustrates schematically some exemplary embodiments of the present disclosure implemented in the system illustrated in FIG. [Figure 10] FIG. 10 illustrates schematically some exemplary embodiments of the present disclosure implemented in the system illustrated in FIG. [Figure 11] FIG. 11 illustrates schematically some exemplary embodiments of the present disclosure implemented in the system illustrated in FIG. [Figure 12] FIG. 12 illustrates schematically some exemplary embodiments of the present disclosure implemented in the system illustrated in FIG. [Figure 13] FIG. 13 illustrates schematically some exemplary embodiments of the present disclosure implemented in the system illustrated in FIG. [Figure 14] FIG. 14 illustrates schematically some exemplary embodiments of the present disclosure implemented in the system illustrated in FIG. [Figure 15] FIG. 15 illustrates schematically some exemplary embodiments of the present disclosure implemented in the system illustrated in FIG. [Figure 16] FIG. 16 illustrates schematically some exemplary embodiments of the present disclosure implemented in the system illustrated in FIG. [Figure 17] FIG. 17 illustrates schematically some exemplary embodiments of the present disclosure implemented in the system illustrated in FIG. [Figure 18]FIG. 18 illustrates schematically some exemplary embodiments of the present disclosure implemented in the system illustrated in FIG. [Figure 19] FIG. 19 illustrates schematically some exemplary embodiments of the present disclosure implemented in the system illustrated in FIG. [Figure 20] FIG. 20 illustrates schematically some exemplary embodiments of the present disclosure implemented in the system illustrated in FIG. [Figure 21] FIG. 21 illustrates schematically some exemplary embodiments of the present disclosure implemented in the system illustrated in FIG. [Figure 22] FIG. 22 illustrates schematically some exemplary embodiments of the present disclosure implemented in the system illustrated in FIG. [Figure 23] FIG. 23 illustrates schematically some exemplary embodiments of the present disclosure implemented in the system illustrated in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0039] overview FIG. 1 illustrates schematically a mobile telecommunications system 1 (cellular or wireless) to which exemplary embodiments of the present disclosure may be applied.

[0040] In this system 1, users of mobile devices 3 (UE) can communicate with each other and other users via base stations 5 (and other access network nodes) and a core network 7 using an appropriate 3GPP Radio Access Technology (RAT), e.g., Evolved Universal Terrestrial Radio Access (E-UTRA) and / or 5G RAT. It will be understood that several base stations 5 form a (Radio) Access Network, or (R)AN. As those skilled in the art will appreciate, while one mobile device 3 and two base stations 5A / 5B are shown in FIG. 1 for illustrative purposes, the system, when implemented, will typically include other base stations / (R)AN nodes and mobile devices (UE).

[0041] Each base station 5 controls one or more associated cells (directly or via other nodes such as home base stations, relays, remote radio heads, distributed units, etc.). Base stations 5 that support next generation / 5G protocols may be referred to as "gNBs." It will be appreciated that some base stations 5 may be configured to support both 4G and 5G communication protocols, and / or any other 3GPP or non-3GPP communication protocol.

[0042] A mobile device 3 and its serving base station 5 are connected via an appropriate radio interface (e.g., the so-called "NR" radio interface, the "Uu" interface, etc.). Adjacent base stations 5 may be connected to each other via an appropriate inter-base station interface (e.g., the so-called "Xn" interface, the "X2" interface, etc.). Base stations 5 are also connected to core network nodes via appropriate interfaces (e.g., the so-called "NG-U" interface (for the user plane), the so-called "NG-C" interface (for the control plane), etc.).

[0043] The core network 7 (e.g., EPC in the case of LTE or NGC in the case of NR / 5G) typically includes logical nodes (or "functions") for subscriber management, mobility management, charging, security, and call / session management (among other things) to support communications in the telecommunications system 1. For example, the core network 7 in a "next generation" / 5G system includes user plane and control plane entities, such as one or more Control Plane Functions (CPFs) 10 and one or more User Plane Functions (UPFs) 11. For example, the so-called Access and Mobility Management Function (AMF) 9 in 5G, or the Mobility Management Entity (MME) in 4G, is responsible for handling connectivity and mobility management tasks for mobile devices 3. The so-called Session Management Function (SMF) is responsible for handling communication sessions for mobile devices 3, such as session establishment, modification, and release. The core network 7 may also typically include, among other things, an Authentication Server Function (AUSF), a Unified Data Management (UDM) entity, a Policy Control Function (PCF), and an Application Function (AF). It will be understood that nodes or functions may have different names in different systems. The core network 7 connects (via the UPF 11) to a Data Network (DN), such as the Internet or a similar Internet Protocol (IP)-based network. The core network 7 may also be connected to an Operations and Maintenance (OAM) function (not shown).

[0044] In this system 1, Cross Link Interference (CLI) can occur in the form of remote interference. Such remote interference occurs when atmospheric conditions allow radio waves to propagate from a transmitter (in this case base station 5A) to a remote location (in this case the location of base station 5B), where these radio waves can interfere with local transmissions. As shown in Figure 1, remote interference can occur well beyond the normal transmission range of a base station (gNB), which can be as little as a few kilometers. In this scenario, the following definitions can be used: Aggressor gNB: A base station transmitting on the downlink that causes (or has the potential to cause) interference. Victim gNB: A base station receiving on the uplink that is affected by interference. Inter-gNB CLI: Interference caused by downlink transmissions from an aggressor gNB to a victim gNB with uplink reception. Victim UE: A UE that has uplink transmissions to a victim gNB and is affected by an inter-gNB CLI.

[0045] Thus, in the example shown in FIG. 1, the first base station 5A is the aggressor of the CLI, and the second base station 5B and the UE 3 are victims of the CLI.

[0046] To mitigate or reduce the effects of such remote interference, the nodes of system 1 are configured to perform one or more of the following procedures.

[0047] In a first step, the victim base station 5B identifies an aggressor base station 5A from among multiple potential aggressors based on configuration information regarding the CLI for each of the potential aggressors.

[0048] In the second procedure, the aggressor base station 5A transmits at least one reference signal for measuring CLI caused by radio transmissions from the aggressor base station 5A outside the serving area of ​​the aggressor base station 5A.

[0049] In a third procedure, the base stations 5A and 5B configure at least one resource for measuring CLI outside the serving area of ​​the transmitter of the aggressor base station 5A. The level of CLI is determined based on the received signal strength value of a CLI reference signal from the transmitter of the aggressor base station 5A through the at least one resource.

[0050] In a fourth step, the victim base station 5B detects, based on the associated reference signal, the occurrence of a CLI that occurs outside the serving area (cell) of the aggressor base station 5A. The victim base station 5B transmits information indicating the occurrence of the CLI to a node responsible for CLI management (which may be another base station or an OAM function).

[0051] In the fifth procedure, the UE 3 and the aggressor base station 5A are configured to transmit so that the arrival time of the uplink signal from the UE 3 at the victim base station 5B coincides with the arrival time of the CLI reference signal from the aggressor base station 5A.

[0052] Advantageously, using one or more of the following procedures, nodes of this system 1 can mitigate or reduce harmful remote interference.

[0053] User Equipment (UE) FIG. 2 is a block diagram illustrating the main components of the mobile device (UE) 3 shown in FIG. 1. As illustrated, the UE 3 includes a transceiver circuit 31 operable to transmit signals to and receive signals from at least one connected node via one or more antennas 33. While not necessarily shown in FIG. 2, the UE 3 naturally has all the usual functionality of a conventional mobile device (such as a user interface 35), which may be provided by any one or any combination of hardware, software, and firmware, as appropriate. A controller 37 controls the operation of the UE 3 according to software stored in memory 39. The software may be pre-installed in memory 39 and / or downloaded, for example, via the telecommunications network 1 or from a removable data storage device (RMD). The software includes, among other things, an operating system 41, a communications control module 43, and an interference (e.g., CLI) management module 45.

[0054] The communications control module 43 is responsible for processing (generating / sending / receiving) signaling messages and uplink / downlink data packets between the UE 3 and other nodes, including the (R)AN node 5 and core network nodes. The signaling may include control signaling related to CLI management, such as configuring resources for CLI reference signals and measurements. The communications control module 43 is also responsible for determining and applying the appropriate TDD and / or FDD configuration.

[0055] The interference / CLI management module 45 is responsible for CLI management, including receiving and applying relevant reference signal configurations (via the communications control module 43).

[0056] Access network node (base station) FIG. 3 is a block diagram illustrating the main components of the base station 5 (or similar access network node) shown in FIG. 1. As illustrated, the base station 5 includes transceiver circuitry 51 operable to transmit signals to and receive signals from at least one connected UE 3 via one or more antennas 53, and to transmit signals to and receive signals from other network nodes (directly or indirectly) via a network interface 55. The network interface 55 typically includes an appropriate base station-to-base station interface (such as an X2 / Xn interface) and an appropriate base station-core network interface (such as an S1 / N1 / N2 / N3 interface). A controller 57 controls the operation of the base station 5 according to software stored in memory 59. The software may be pre-installed in memory 59 and / or downloaded, for example, via the telecommunications network 1 or from a removable data storage device (RMD). The software includes, among other things, an operating system 61, a communications control module 63, and an interference (e.g., CLI) management module 65.

[0057] The communications control module 63 is responsible for handling (generating / sending / receiving) signaling between the base station 5 and other nodes, such as the UE 3 and core network nodes. The signaling may include control signaling related to CLI management, such as configuring resources for CLI reference signals and measurements. The communications control module 63 is also responsible for controlling and applying the appropriate TDD and / or FDD configuration.

[0058] The interference / CLI management module 65 is responsible for CLI management in the radio access network part to which the access network node belongs, and for exchanging CLI related assistance information with other access network nodes (directly or via the core network 7).

[0059] Core Network Functions 4 is a block diagram illustrating the main components of a typical core network function, such as the CPF 10 or UPF 11 shown in FIG. 1. As shown, the core network function includes a transceiver circuit 71 operable to transmit signals to and receive signals from other nodes (including UEs 3, base stations 5, and other core network nodes) via a network interface 75. A controller 77 controls the operation of the core network function in accordance with software stored in memory 79. The software may be pre-installed in memory 79 and / or may be downloaded, for example, via the communications network 1 or from a removable data storage device (RMD). The software includes, among other things, an operating system 81, a communications control module 83, and an interference (e.g., CLI) management module 85.

[0060] The communication control module 83 is responsible for handling (generating / sending / receiving) signaling between the core network functions and other nodes such as the UE 3, the base station 5, and other core network nodes. The signaling may include control signaling related to CLI management, such as configuration of resources for CLI reference signals and measurements.

[0061] The interference / CLI management module 85 is responsible for supporting CLI management in the part of the radio access network served by the core network node.

[0062] Detailed Description In this disclosure, the following definitions are used: Aggressor gNB: Base station (gNB) transmitting in DL Victim gNB: Base station (gNB) receiving on UL Inter-gNB CLI: Interference from DL transmissions from an aggressor gNB to a victim gNB receiving UL signals Victim UE: A UE that transmits UL to a victim gNB and is affected by an inter-gNB CLI

[0063] The above nodes and their relationships are shown schematically in FIG.

[0064] How to Identify Aggressors 9 schematically illustrates an exemplary scenario in which an aggressor base station 5A (denoted as "gNB 5A") generates CLI to a victim base station 5B (denoted as "gNB 5B"). Specifically, transmitter (Tx) beam #1 of base station 5A generates interference to receiver (Rx) beam #1 of base station 5B.

[0065] In this scenario, the victim base station 5B needs to identify the interferer (in this example, base station 5A) in order to mitigate the interference from that particular aggressor. In the case of beamforming, as shown in FIG. 9, not only the aggressor node, e.g., gNB 5A, but also the aggressor beam, e.g., Tx beam #1 of gNB 5A, should be identified. Once the aggressor base station / beam is identified, the interference can be mitigated by, for example, not scheduling UEs 3 covered by the aggressor beam during one or more specific symbols / slots corresponding to the period when the aggressor base station 5A transmits in the downlink, more specifically, the period when the signal transmitted by the aggressor base station 5A arrives at the cell of the victim base station 5B (with a delay that depends on the distance between the two base stations 5A and 5B).

[0066] In the case of remote interference, the aggressor and victim nodes may be located at a relatively large distance from each other, so they are not considered neighbors for the purposes of mobility, load balancing, dual connectivity, and / or similar normal network operations.

[0067] In this example, the base stations 5 have an inter-base station interface (e.g., an Xn interface, and / or the like) between them. Advantageously, the base stations 5A and 5B may be configured to exchange information suitable for assisting other base stations in CLI mitigation over the Xn interface (or other inter-base station interface). Specifically, the base station 5 (at least the aggressor 5A) may be configured to transmit configuration information that may be related to CLI management (including TDD configuration, beam configuration, and reference signal configuration, and / or the like) to the other base stations 5. The base stations 5 may exchange this information once (e.g., upon establishment or connection between them) or periodically (on demand, periodically, or in response to changes in their configuration) to assist each other in dynamic TDD operation.

[0068] It will be appreciated that if a direct base station-to-base station interface (e.g., an Xn interface) is not available for information exchange, relevant information may be exchanged between two base stations over the Ng interface and / or the like using RRC containers. For example, the aggressor base station 5A may transmit this information (over the Ng interface using one or more appropriate RRC containers) to the core network 7, which may then forward the information (at least one RRC container) to one or more other base stations 5B, where the other base stations 5B may be one or more victims of a CLI caused by the transmission from base station 5A.

[0069] 10 illustrates an exemplary procedure for identifying an aggressor base station (denoted "gNB 5A") by a victim base station (denoted "gNB 5B") using the approach described above. In this case, the base stations 5A and 5B exchange appropriate assistance information over an inter-base station interface (e.g., Xn and / or the like) between them.

[0070] In this example, there are five base stations 5, of which gNB 5B is the victim base station and gNB 5A is the aggressor. Rx beam #1 of gNB 5B receives CLI from (the beam of) gNB 5A.

[0071] In this approach, the victim base station 5B identifies the aggressor 5A based on applicable TDD configuration, beam configuration, and gNB location information exchanged over the inter-base station interface (or over the core network 7). In other words, at least some of the base stations shown in Figure 10 are configured to support such information exchange to assist CLI management.

[0072] The procedure includes the following steps:

[0073] Step 1: The victim base station 5B exchanges TDD configuration information with surrounding base stations 5, and through such information knows which at least one base station 5 performs DL transmission when performing UL reception in one or more specific symbols / slots. A list of potential aggressors is created accordingly.

[0074] The exchanged information may include, for example, common or dedicated uplink / downlink configurations (which may be included in so-called tdd-UL-DL-ConfigurationCommon and tdd-UL-DL-ConfigurationDedicated information elements, respectively), Downlink Control Information (DCI) format (e.g., DCI format 2_0), and any additional parameters related to subband non-overlapping full-duplex operation, such as one or more symbols / slots / frequency bands to be used for the UL and / or DL.

[0075] The exact type of information to be exchanged and the frequency of the information exchange may depend on the performance of the interface used between the base stations 5. It will be appreciated that a subset of the parameters described above may be exchanged.

[0076] In this example, after step 1, the victim base station 5B may be able to narrow down the potential aggressors (based on the exchanged information) to an initial set (or list) of potential aggressor nodes including base stations 5A, 5C, 5D, and 5E that have exchanged relevant TDD (or CLI) related information with the victim base station 5B.

[0077] Step 2: Based on the locations of other base stations, the victim base station 5B may further derive potential aggressors based on its own location and information related to the Rx beam (e.g., beam direction, beam width, etc.) to reduce the size of the initial list. In this example, after step 2, the victim base station 5B may narrow down the initial set (list) of potential aggressor nodes to base stations 5A and 5C (i.e., remove base stations 5D and 5E from the list of potential aggressors).

[0078] Step 3: The victim base station 5B and its surrounding base stations 5 exchange transmit beam configuration information (e.g., beam direction, beam width, configuration of related reference signals such as NZP-CSI-RS, SSB, etc.). It will be understood that this information may be exchanged as part of the information exchanged in step 2. Based on this information, the victim base station 5B may be able to identify one or more potential aggressor beams. In this example, the victim base station 5B may be able to narrow down the potential aggressors to base station 5A and that particular beam of base station 5A.

[0079] (Optional) Step 4: Each base station 5 may be configured to share its aggressor list and / or aggressor beam list with a centralized controller. The centralized controller may be, for example, an Operations Administration and Maintenance (OAM) function or one of the base stations, depending on whether a centralized or distributed CLI management mechanism is used. Alternatively, the victim base station 5B may indicate to the centralized controller that it is experiencing a CLI, and the centralized controller may perform steps 1-3 to derive a list of aggressor nodes and / or beams (at least one aggressor node and / or beam) for the victim base station 5B and send this list to the victim base station 5B.

[0080] It will be appreciated that there may be more than one aggressor (and / or more than one beam or cell may be subject to CLI), in which case the procedure may be applied separately to each aggressor or beam / cell, or, if appropriate, a single procedure may identify more than one aggressor or beam.

[0081] It will be appreciated that the process may stop at any step between steps 1-3 to provide different levels or granularity of aggressor identification. Accordingly, the following alternatives are envisioned: Alternative 1: By performing only step 1, the aggressor gNB list {5A, 5C, 5D, 5E} is available. Alternative 2: By performing steps 1 and 2, a more specific, reduced-size aggressor gNB list {5A, 5C} is available. Alternative 3: By performing steps 1, 2, and 3, a further reduced size (or specific aggressor, as in this example) aggressor gNB list {gNB 5A} is available.

[0082] Advantageously, the victim base station 5B can identify aggressor nodes (at least a list of potential aggressor nodes) based on available information and take appropriate action to mitigate CLI caused by one or more aggressor nodes.

[0083] To ensure effective CLI management, the aggressor gNB / beam list may need to be updated. This may be updated on demand (e.g., when a CLI is detected again), replaced when the TDD / beam configuration of one of the base stations changes, or updated periodically (e.g., based on an associated timer), depending on the performance of the Xn interface.

[0084] It will also be appreciated that once an aggressor base station 5A is identified, the aggressor base station 5A may indicate its transmit power to the victim base station 5B. Alternatively, transmit power information may be provided by each potential aggressor node, and this information may be used in any of steps 1 through 3.

[0085] The transmit power information may be used by the victim base station 5B to determine whether the transmissions of a (potential) aggressor base station will interfere with the victim base station 5B.

[0086] 11 and 12 schematically illustrate another exemplary procedure for identifying aggressor base stations without having (or using) an inter-base station interface between base stations. In this case, beam sweeping (FIG. 11) or nulling beam sweeping (FIG. 12) is used to identify the aggressor.

[0087] More specifically, one or more aggressor nodes may be identified based on associated TDD configuration and location information (exchanged over the Xn interface) without exchanging (or having the ability to exchange) beam information between base stations 5.

[0088] In this scenario, steps 1 and 2 may be the same as those described above with reference to FIG.

[0089] However, in step 3, each potential aggressor base station 5 performs a beam sweep or nulling beam sweep operation to help the victim base station 5B measure the CLI level (or change in CLI level) that is used to identify which beam causes CLI to that particular victim base station 5B. The measured CLI level (or change in CLI level) may be reported to the associated potential aggressor node. Based on this report, the potential aggressor node (gNB) can determine whether it is an aggressor with respect to other nodes and identify which Tx beam is the aggressor beam (or multiple aggressor beams).

[0090] In the case of beam sweeping, the (aggressor) base station 5A turns on its beams one by one (in other words, schedules downlink communications via different beams in sequence), and the victim base station 5B reports the measured CLI levels to base station 5A. Based on this reporting, base station 5A can identify beams that cause high levels of CLI (e.g., CLI above an associated threshold).

[0091] In the case of nulling beam sweep, the (aggressor) base station 5A turns off its beams one by one (in other words, does not schedule downlink communications via different beams in sequence), and the victim base station 5B reports the changes in the measured CLI level to base station 5A. In this case, the aggressor beam causes the largest change in CLI level. Based on this report, base station 5A can identify the aggressor beam.

[0092] It will be appreciated that beam sweeping may be performed in an active or passive manner. When active beam sweeping is used, the aggressor base station 5A may actively configure appropriate reference signals for beam sweeping (e.g., CSI-RS / SSB reference signals, described below); in this case, the beam may not necessarily be the beam used for actual data transmission within the cell of the base station 5A. This approach may beneficially reduce interruptions caused to the transmission of the base station 5A by the beam sweeping operation. Furthermore, it can be used to identify additional potential aggressing beams (which may cause CLI to other base stations in the future). For each Tx beam, the victim base station 5B reports the respective measurement results to the base station 5A.

[0093] When passive beam sweeping is used, the aggressor base station 5A performs beam sweeping only for beams that are currently being used (or expected to be used soon). For the currently used beams, a demodulation reference signal (DMRS) or even data may be used for CLI measurements by the victim base station 5B. For other beams, CSI-RS / SSB may be used. For each Tx beam, the victim base station 5B reports the respective measurement results to the base station 5A.

[0094] The nulling beam sweep method may be applied only to the beam currently being used for data transmission.

[0095] What to measure? It will be appreciated that any of the following approaches may be used for CLI management. Alt1: Measure reference signals, such as Channel State Information Reference Signals (CSI-RS), Synchronization Signal Blocks (SSB), Demodulation Reference Signals (DMRS): in this case, the configuration of the applied reference signals needs to be exchanged between the base stations; -Alt2: Measure data transmission from aggressors; and -Alt3: Perform blind measurements.

[0096] To support CLI specific measurements, the following measurement capabilities are proposed for base station 5: -(For Alt1) CLI CSI-RS RSRP measurement; -(Alt2) gNB CLI-RSSI measurement.

[0097] In the case of Alt1, the CLI CSI reference signal received power (CLI CSI-RSRP) is defined as the linear average of the power contributions (in watts) of the resource elements of one or more antenna ports transmitting the indicated CSI reference signal for the CLI RSRP measurement within the measurement frequency bandwidth considered in the indicated CSI-RS opportunity.

[0098] For the determination of the CSI CSI-RSRP, it shall be indicated on which antenna port the CSI reference signal is transmitted, and it is expected that the base station 5 can measure one or more CLI CSI-RS resources outside the active downlink bandwidth portion.

[0099] In detail, the CLI CSI-RSRP reference points are: -For Type 1-C base station: Rx antenna connector, For a type 1-O or 2-O base station: based on the composite signal from the antenna elements corresponding to a specific receiver branch, For Type 1-H Base Stations: Rx Transceiver Array Boundary Connector.

[0100] In the above list, Type 1-C, Type 1-O, Type 2-O, and Type 1-H base stations correspond to the respective definitions set out in 3GPP TS 38.104.

[0101] For frequency ranges 1 and 2, if receiver diversity is used by base station 5, the reported CLI CSI-RSRP value must not be lower than the corresponding CLI CSI-RSRP of any of the individual receiver branches.

[0102] It should be noted that Alt1 may be extended to other reference signals such as SSB, DMRS, etc., depending on the base station's choice.

[0103] For Alt2, the gNB-specific CLI Received Signal Strength Indicator (CLI-RSSI) is defined as the linear average of the total received power (in watts) observed only in the indicated OFDM symbols for one or more indicated measurement time resources, observed in the indicated measurement bandwidth from all sources including co-channel serving and non-serving cells, adjacent channel interference, self-interference, thermal noise, etc.

[0104] It is expected that the base station 5 will be able to measure one or more resources outside of the active downlink bandwidth portion.

[0105] The reference point for gNB CLI RSSI is -For Type 1-C base station: Rx antenna connector, For a type 1-O or 2-O base station: based on the composite signal from the antenna elements corresponding to a specific receiver branch, For Type 1-H Base Stations: Rx Transceiver Array Boundary Connector.

[0106] For frequency ranges 1 and 2, if receiver diversity is used by base station 5, the reported gNB CLI RSSI value must not be lower than the gNB CLI RSSI corresponding to any individual receiver branch.

[0107] When to measure? Regarding the question of when to trigger the measurement of CLI, two main cases and several associated solutions can be identified.

[0108] Case 1: When a so-called full Xn interface is used between base stations, both the victim base station 5B and the aggressor base station 5A know when and where a CLI occurs based on TDD-related configuration information exchanged between them. In this case, the following solution can be used: Solution 1: UE UL transmission is allowed when gNB-gNB CLI occurs, as the CLI level may not be high enough to affect UL transmission. CLI measurements may be performed during UL transmission from the first symbol / slot where gNB CLI occurs. Solution 2: If gNB-gNB CLI measurements are performed, UE UL transmission is not allowed and the victim base station 5B may need to perform CLI measurements before UL transmission.

[0109] Case 2: When an incomplete Xn interface is used between base stations, the victim base station 5B and the aggressor base station 5A may not have exchanged all (or any) TDD-related configuration information and therefore may not have sufficient knowledge of when and where CLI occurs. Solution: In this case, CLI measurements may be performed when the performance of UL transmissions is affected, which may be indicated, for example, by a higher associated Block Error Rate (BLER) value or a lower associated Signal-To-Interference-Plus-Noise Ratio (SINR) value.

[0110] Another solution (for either case 1 or case 2) allows the victim base station 5B to measure the CLI periodically without an associated trigger, or all solutions may be flexibly combined.

[0111] For both cases, the parameter T delta (T Δ ) may be defined and configured to indicate the time difference between the time of CLI measurement and the time when the CLI mitigation is expected to be applied. This parameter may be communicated to the UE 3 so that the UE 3 knows when the CLI can be mitigated.

[0112] Figure 13 shows the T value based on a value (T0) that represents the time when CLI measurements are initiated and another value (T1) that represents the time when CLI relaxation is expected to be applied. Δ 10 shows an example method for defining

[0113] Note that the behavior of the Xn interface described above may also apply to the Ng interface if the Xn interface is not available.

[0114] Measurement method Figure 14 illustrates schematically an exemplary approach to performing measurements for CLI mitigation in the system of Figure 1. In this case, the following definitions apply (in addition to those given with reference to Figure 8): Aggressor gNB: A base station (gNB) that configures and transmits non-zero power (NZP) reference signals such as CSI-RS, DMRS, and SSB to indicate the gNB-gNB CLI level. Victim gNB: A base station (gNB) that configures one or more time-frequency resources as CLI measurement reference signals / resources and measures the signal strength received on those resources, e.g., by receiving CSI-RS from an Aggressor gNB. gNB-gNB CLI: Signal strength of NZP RS from aggressor gNB, indicating the interference level of gNB-gNB CLI. Victim UE: A UE configured with a set of one or more time-frequency resources for CLI measurements by a victim gNB.

[0115] The issue of how to measure CLI will be explained in more detail with reference to Figures 15 to 17.

[0116] Figure 15 shows a first alternative. In this case, a new RS type, for example, a Zero Power (ZP) SRS, is configured in the victim UE 3. The victim base station 5B measures the CLI on one or more ZP SRS resources. It will be understood that the ZP SRS may be configured for one or more resources / resource sets for one or more beams / gNBs according to similar (or identical) configuration rules as the SRS. In the example shown in Figure 15, the ZP SRS (for the CLI) is configured for one or more symbols following the regular SRS symbol. It will be understood that the number of ZP SRSs may be up to n_max OFDM symbols, where n_max is an integer having a value less than or equal to 12.

[0117] The comb factor of the ZP SRS may be selected from the set {1, 2, 4, 8, 16} depending on the maximum number of aggressors (e.g., comb factor 1 in FIG. 15). Thus, the number of measurable aggressors is given by n_max*comb_factor*n_code, where n_code is the number of orthogonal codes in the code domain.

[0118] Figure 16 shows a second alternative. In this case, an appropriate (CLI-specific) puncturing pattern is configured for victim UE 3. UL data and / or SRS may be punctured for the time and frequency resources indicated in the associated pattern configuration. It will be appreciated that as data is punctured, the actual coding rate for the UL will be higher.

[0119] Figure 17 shows the third alternative, in which a ZP CLI management RS is configured for victim UE3. Compared to the second alternative above, the actual coding rate and UL channel sounding performance remain unchanged.

[0120] It will be appreciated that multiple resources and resource sets may be configured for each base station 5. Each resource may correspond to a respective aggressor beam, for example, CLI IM RS#1 for Tx beam #1 of the aggressor base station 5A, CLI IM RS#2 for Tx beam #2 of the (same) aggressor base station 5A, and CLI IM RS#3 for Tx beam 3. Each resource set may correspond to a specific aggressor base station 5A, for example, CLI IM RS#1, #2, and #3 may belong to the same resource set corresponding to one aggressor base station 5A.

[0121] In a fourth alternative, ZP CSI-RS resources may be configured for the UEs 3 served by the victim base station 5B for rate matching / puncturing purposes when a CSI-RS type resource configuration is used for the CLI.

[0122] Compared to the ZP CSI-RS resource configuration for DL ​​rate matching / puncturing currently supported in NR, in this System 1, resources may also be used for UL rate matching / puncturing. Similar to the DCI-based indication for the Physical Downlink Shared Channel (PDSCH), the DCI for the Physical Uplink Shared Channel (PUSCH) may also be adapted to indicate which ZP CSI-RS resources to activate.

[0123] FIG. 18 shows a schematic of a potential timing problem in the CLI case, namely misaligned transmissions by the aggressor and victim (in this case the UE).

[0124] Thus, the arrival times of the UL signal from victim UE 3 and the interference signal from aggressor base station 5A may not coincide due to the distance between them: the UL signal from victim UE 3 arrives at time T0, and the interference signal from the aggressor arrives (at victim base station 5B) at time T1.

[0125] Timing difference T Δ1 = T1 - T0 depends on the propagation delay and may be greater than the duration of the applicable cyclic prefix (CP), which may affect the measurement of CLI. In Figure 18, the following definitions apply: T0: Arrival timing of UL signal from victim UE3 T1: Arrival timing of interference signal from aggressor node (gNB 5A)

[0126] In this example, DL transmissions across network 1 are synchronized, i.e., T_DL denotes the DL timing of both base station 5A and base station 5B. T_DL may also include UL / DL or Tx / Rx transition times, and is therefore expected to be (substantially) equal to or close to T0.

[0127] UE3 is TA=N TA +N TA,offset It consists of an associated Timing Advance (TA) value (in ms) given by: Thus, as shown in Figure 19, UE3 transmits TA ms earlier than T0.

[0128] To support efficient CLI management, the following solutions have been proposed: Alt1: The aggressor base station 5A is T Δ2=T0-T3 [ms] earlier (where T0 represents the corresponding DL timing of the victim base station 5B). In a synchronous network, T_DL applies to both the aggressor base station 5A and the victim base station 5B. T_DL may also include UL / DL or Tx / Rx transition times, and is therefore expected to be (substantially) equal to or close to T0.

[0129] An example of this solution is shown in Figure 20.

[0130] In this case, T Δ2 is less than or equal to the distance between the aggressor base station 5A and the victim base station 5B divided by c (the speed of light, or in this case the speed of radio waves). This ensures that the arrival times of the UL signal from the victim UE and the interference signal from the aggressor base station 5A match. In this context, matching means that T Δ1 This means that =T1-T0 is smaller than the period of the CP used in the cell of the victim base station 5B.

[0131] There is no need to change the behavior of UE3. Therefore, Alt1 may depend on the implementation of the base station (gNB).

[0132] Alt2: In this case, the aggressor base station 5A does not transmit its reference signal earlier as this may affect its own DL transmission timing. However, the victim UE 3 aligns its UL transmission with the downlink signal from the aggressor base station 5A (T Δ3 The delay time is configured to delay its transmission by an amount indicated by .

[0133] An example of this solution is shown in FIG. 21, where T_DL=T3 represents the DL timing of both the aggressor base station 5A and the victim base station 5B (assuming a synchronous network).

[0134] T Δ3 The arrival time of the UL signal from the victim UE 3 and the interference signal from the aggressor base station 5A coincides (i.e., TΔ1 =T1-T0 is configured to be smaller than the period of the CP used in the cell of the victim base station 5B. Δ3 It will be appreciated that the UE's Timing Advance (TA) value may be absorbed by the UE's Timing Advance (TA) value. In this case, a negative TA value may be required.

[0135] In Alt2, the UL transmission of victim UE3 is delayed, which may cause the UE's own UL / DL to become misaligned. This issue may be addressed by introducing an additional GP (between the UL and DL resources).

[0136] Measurement Report 22 and 23, below is a discussion of some exemplary ways in which measurements may be reported to perform appropriate CLI management action. Alt1 (Figure 22): In case of centralized CLI management, report the measurement results to a centralized controller (e.g., OAM). Alt2 (Figure 23): In case of distributed CLI management, report the measurement results to the aggressor node (e.g., via the Xn interface).

[0137] Reporting may be periodic, semi-persistent, and / or aperiodic (on-demand).

[0138] In the case of semi-persistent and on-demand aperiodic reporting, reporting may be based on (in response to) a request from the OAM or aggressor, or may be initiated by the victim base station 5B when the detected / measured interference exceeds an associated threshold, which may be predefined or configured based on the signal power received on the UL.

[0139] CLI-RS Resource Configuration Below are descriptions of some example ways to configure a CLI-specific reference signal (CLI-RS) and when to transmit the CLI-RS.

[0140] The CLI-RS resource may have a persistent / semi-persistent periodicity or may be an aperiodic CLI-RS resource.

[0141] In the case of persistently allocated resources, cell-specific legacy RS (such as CSI-RS or SSB) may be used for measurements.

[0142] In the case of semi-persistent / aperiodic resources, the base stations 5 may exchange information about the time opportunities for their RS transmissions. This exchange may be triggered, for example, when a TDD conflict is identified by one of the base stations 5.

[0143] In one alternative, the victim base station 5B may request the aggressor base station 5A to transmit a CLI-RS, and the aggressor base station 5A may indicate applicable resource reservations and transmit the CLI-RS accordingly.

[0144] In another alternative, the aggressor base station 5A transmits its CLI-RS and provides information to the victim base station 5B (on its own, i.e., without a request from the victim base station 5B) regarding the used CLI-RS resource configuration.

[0145] Regarding the question of when to transmit the CLI-RS, the time resource for the CLI-RS may be defined at the slot / symbol level. The slot / symbol type used for the CLI-RS transmission may be selected as follows: 1) The victim base station 5B is able to measure and receive the RS, which means that the CLI-RS transmission should occur during the victim UL slot / symbol or when the victim base station 5B is not transmitting. 2) CLI-RS transmission occurs during DL slots or when there is no transmission so that the DL RS does not interfere with UL reception.

[0146] According to point 2 above, RS should be sent as follows: Option 1: Transmit CSI-RS in one or more DL slots / symbols of the aggressor base station that overlap with one or more UL slots / symbols of the victim base station (this means that CLI-RS is transmitted only in the conflicting slots). Option 2: Transmit CSI-RS in one or more UL slots / symbols of the victim base station that overlap with any flexible slot of the aggressor base station. Option 3: Transmit CSI-RS in the DL slots / symbols of the aggressor base station that overlap with the flexible slots of the victim base station. Option 4: Both victim and aggressor base stations transmit CSI-RS in overlapping flexible slots.

[0147] To implement options 2 to 4, base stations may need to share information about flexible time opportunities with each other.

[0148] The type of CLI-RS resource used may also depend on the slot / symbol types of the aggressor and victim base stations, respectively. For example, if the victim base station's UL slot / symbol is used for CLI-RS transmission, an SRS-type resource configuration may be used. Otherwise, a CSI-RS-type resource configuration may be used.

[0149] It will be appreciated that additional restrictions may be applied to the CLI-RS transmission so that the CLI-RS is transmitted at least a certain period before the start of the contention slot. Such additional restrictions on CLI-RS timing may be implemented using fixed values ​​(e.g., defined in the relevant 3GPP specifications) or values ​​determined by the victim base station and indicated to the aggressor base station.

[0150] If the CSI-RS is transmitted to avoid contention in the DL+UL slot, the CLI-RS may be transmitted only on frequency resources and beams where contention is expected to occur (i.e., DL of the aggressor base station and UL of the victim base station). It will be appreciated that this information (i.e., frequency resource / beam information) may need to be exchanged between base stations.

[0151] Modifications and Alternatives Detailed example embodiments have been described above, and as those skilled in the art will appreciate, having the benefit of the disclosure embodied therein, many modifications and alternatives may be applied to the above example embodiments.

[0152] For example, for clarity, terminology specific to a cellular communication generation (2G, 3G, 4G, 5G, 6G, etc.) may be used to refer to a particular communication entity, but it will be understood that technical features described for a given entity are not limited to devices of that particular communication generation. The technical features may be implemented in any functionally equivalent communication entity, regardless of any differences in the terminology used to refer to them.

[0153] It will be appreciated that when subband full duplex (SBFD) operation is used, the CLI-RS or puncturing pattern may be configured within one or more subbands. The CLI-RS or puncturing pattern may be configured in a periodic, semi-persistent, or dynamic manner. In the case of periodic and semi-persistent configuration, Radio Resource Control (RRC) signaling (e.g., one or more appropriately formatted information elements) may be used to configure the CLI-RS or puncturing pattern, and Medium Access Control (MAC) signaling (e.g., MAC control elements) may be used to activate / deactivate the CLI-RS or puncturing pattern. In the case of dynamic configuration, appropriately formatted Downlink Control Information (DCI) may be used for configuration / activation / deactivation, or RRC may be used for configuration and DCI may be used for activation / deactivation.

[0154] The type of CLI-RS or puncturing resource may depend on the CLI-RS resource configuration type. For example, if the CLI-RS resource configuration is of SRS type, the first alternative described above (ZP SRS, FIG. 15) may be used, and if the CLI-RS resource configuration is of CSI-RS type, the fourth alternative described above (ZP CSI-RS resource) may be used.

[0155] Multiple CLI measurement RS resources / resource sets may be configured in different time and frequency resources for a single aggressor base station so that multiple Tx beams can be measured simultaneously. One or more identical CLI measurement RS resources / resource sets may be configured for multiple beams as long as the sequences of one or more RSs associated with these beams are orthogonal to each other.

[0156] With respect to one or more frame structures that may be used in the above-described communication systems, it will be understood that the base station and the UE communicate with each other using resources organized in the time domain into frames of length 10 ms. Each frame includes 10 equally sized subframes of length 1 ms. Each subframe is divided into one or more slots including 14 Orthogonal Frequency-Division Multiplexing (OFDM) symbols of the same length. For example, each column in Figures 15 through 17 may represent one OFDM symbol, and in this case, 14 consecutive symbols in Figures 15 through 17 may represent one subframe.

[0157] However, communication systems support multiple different numerologies (subcarrier spacing (SCS), slot length, and therefore OFDM symbol length). Specifically, each numerology is identified by a parameter μ, where μ=0 represents 15 kHz (corresponding to LTE SCS). Currently, SCS for other values ​​of μ can be derived by effectively scaling up from μ=0 by a power of 2 (i.e., SCS=15x2 μ kHz). The relationship between the parameter μ and SCS (Δf) is shown in Table 1. [Table 1]

[0158] In the above description, the UE, access network nodes (base stations), and core network functions have been described for ease of understanding as having a number of separate functional components or modules. While these modules may be provided in this manner for certain applications, e.g., when an existing system is modified to implement the present disclosure, in other applications, e.g., systems designed from the beginning with the features of the present invention in mind, these modules may be incorporated into an overall operating system or code, and therefore may not be identifiable as separate entities.

[0159] The above example embodiments have described numerous software modules. As those skilled in the art will appreciate, the software modules may be provided to the UE, the access network node (base station), or the core network function in compiled or uncompiled form, as signals over a computer network, or on a recording medium. Furthermore, the functionality performed by some or all of this software may be performed using one or more dedicated hardware circuits. However, the use of software modules is preferred because it facilitates updating the UE, the access network node (base station), or the core network function to update their functionality.

[0160] Each controller may include any suitable form of processing circuitry, including (but not limited to) for example, one or more hardware-implemented computer processors, microprocessors, central processing units (CPUs), arithmetic logic units (ALUs), input / output (IO) circuitry, internal memory / cache (program and / or data), processing registers, communication buses (e.g., control buses, data buses, and / or address buses), direct memory access (DMA) facilities, hardware or software-implemented counters, pointers, and / or timers, etc. Various other modifications will be apparent to those skilled in the art and will not be described in further detail herein.

[0161] Base stations may include "distributed" base stations having a central unit "CU" and one or more separate distributed units (DUs). For example, a gNB may be divided into a CU and one or more DUs connected by a so-called F1 interface. This enables the use of a "split" architecture, whereby the typically "upper" CU layer (e.g., but not necessarily or exclusively, PDCP) and the typically "lower" DU layer (e.g., but not necessarily or exclusively, RLC / MAC / PHY) are implemented separately. Thus, for example, the higher-layer CU functions of multiple gNBs may be implemented centrally (e.g., by a single processing unit or in a cloud-based or virtualized system), while keeping the lower-layer DU functions local at each gNB.

[0162] User Equipment (ie, "UE," "mobile station," "mobile device," or "wireless device") in this disclosure is an entity that connects to a network via a wireless interface.

[0163] It should be noted that the present disclosure is not limited to dedicated communication devices, but may be applied to any device having communication capabilities as described in the following paragraphs.

[0164] The terms "User Equipment" or "UE," "mobile station," "mobile device," and "wireless device" (as the terms are used by 3GPP) are generally intended to be synonymous with each other and include standalone mobile stations such as terminals, cell phones, smartphones, tablets, cellular IoT devices, IoT devices, and machines. It will be understood that the terms "mobile station" and "mobile device" also encompass devices that remain stationary for extended periods of time.

[0165] The UE may be, for example, an item of production or manufacturing equipment and / or an item of energy-related machinery (such as equipment or machinery such as boilers; engines; turbines; solar panels; wind turbines; hydroelectric generators; thermal generators; nuclear generators; batteries; nuclear systems and / or related equipment; heavy electrical machinery; pumps including vacuum pumps; compressors; fans; blowers; hydraulic equipment; pneumatic equipment; metalworking machinery; manipulators; robots and / or application systems thereof; tools; molds or dies; rolls; conveying equipment; elevators; material handling equipment; textile machinery; sewing machinery; printing and / or related machinery; paper processing machinery; chemical machinery; mining machinery and / or construction machinery and / or related equipment; machinery and / or implements for the agricultural, forestry, and / or fisheries industries; safety and / or environmental protection equipment; tractors; precision bearings; chains; gears; power transmission equipment; lubrication equipment; valves; pipe fittings; and / or application systems for any of the foregoing equipment or machinery).

[0166] A UE may be, for example, an item of transportation equipment (such as rolling stock; automobiles; motorcycles; bicycles; trains; buses; carts; human-powered vehicles; ships and other watercraft; aircraft; rockets; satellites; drones; balloons; etc.).

[0167] A UE may be, for example, an item of information and communications equipment (such as electronic computers and related equipment; communications and related equipment; electronic components; etc.).

[0168] The UE may be, for example, a refrigerator, a refrigerator application product, an item of goods and / or service industry equipment, a vending machine, an automated service machine, an office machine or equipment, a consumer electronic device, and an electronic device (e.g., audio equipment; video equipment; loudspeakers; radios; televisions; microwave ovens; rice cookers; coffee machines; dishwashers; washing machines; dryers; electronic fans or related equipment; consumer electronic devices such as vacuum cleaners, etc.).

[0169] The UE may be, for example, an electrical application system or device (such as an electrical application system or device, such as an x-ray system; a particle accelerator; a radioisotope device; a sonic device; an electromagnetic application device; or an electrically powered application device).

[0170] The UE may be, for example, an electronic lamp, a lighting fixture, a measuring instrument, an analyzer, a tester, or, for example, surveying or detecting equipment (such as a smoke alarm; a presence sensor; a motion sensor; a wireless tag), a watch or clock, inspection equipment, optical equipment, medical equipment and / or systems, a weapon, an item of cutlery, a hand tool, etc.

[0171] The UE may be, for example, a wirelessly equipped personal digital assistant or related equipment (such as a wireless card or module designed to be attached to or inserted into another electronic device (e.g., a personal computer, an electrical measuring machine)).

[0172] The UE may be a device or part of a system that uses various wired and / or wireless communication technologies to provide the applications, services, and solutions described below with respect to the Internet of Things (IoT).

[0173] Internet of Things devices (or "Things") can be equipped with appropriate electronics, software, sensors, network connectivity, etc. that enable these devices to collect and exchange data with each other and other communicating devices. IoT devices may include automated equipment that follows software instructions stored in internal memory. IoT devices can operate without the need for human supervision or interaction. IoT devices may also remain stationary and / or inactive for extended periods of time. IoT devices may be implemented as part of (typically) stationary equipment. IoT devices may also be incorporated into non-stationary equipment (e.g., vehicles) or attached to animals or people being monitored / tracked.

[0174] It will be understood that IoT technology may be implemented on any communication device that can connect to a communication network to send / receive data, whether such communication device is controlled by human input or software instructions stored in memory.

[0175] It will be appreciated that IoT devices may also be referred to as Machine Type Communication (MTC) devices or Machine-to-Machine (M2M) communication devices. It will be appreciated that a UE may support one or more IoT or MTC applications. Some examples of MTC applications are listed below in Table 1. This list is not exhaustive and is intended to illustrate some examples of machine type communication applications. [Table 2]

[0176] The applications, services, and solutions may be Mobile Virtual Network Operator (MVNO) services, emergency wireless communication systems, Private Branch eXchange (PBX) systems, PHS / digital cordless communication systems, Point of Sale (POS) systems, advertising call systems, Multimedia Broadcast and Multicast Service (MBMS), Vehicle to Everything (V2X) systems, train radio systems, location-related services, disaster / emergency wireless communication services, community services, video streaming services, femtocell application services, Voice over LTE (VoLTE) services, billing services, wireless on-demand services, roaming services, activity monitoring services, telecommunications carrier / network selection services, feature restriction services, Proof of Concept (PoC) services, personal information management services, ad hoc networks / delay tolerant networking (DTN) services, and the like.

[0177] Furthermore, the above-mentioned UE categories are merely examples of applications of the technical concepts and exemplary embodiments described in this document. Of course, these technical concepts and exemplary embodiments are not limited to the above-mentioned UEs, and various modifications can be made thereto.

[0178] The method performed by the radio access network node may further include receiving respective configuration information and including at least one of the plurality of other radio access network nodes in a list comprising a plurality of candidate aggressor nodes based on the respective configuration information, in which case identifying the aggressor node may include identifying the aggressor node from the list.

[0179] The inclusion may be performed based on at least one of location information associated with the radio access network node, respective location information associated with the transmitters of the candidate aggressor nodes, and characteristics of beams associated with the transmitters of the candidate aggressor nodes.

[0180] The method performed by the radio access network node may further include receiving beam configuration information of at least one other radio access network node, in which case including at least one of the plurality of other radio access network nodes in the list may be performed based on the beam configuration information.

[0181] The method performed by the radio access network node may further include transmitting the list to at least one other node for managing the CLI.

[0182] The method performed by the radio access network node may further include receiving a further list including information identifying at least one candidate aggressor node as a source of CLIs for cells of the further radio access network node, and managing the list based on the further list.

[0183] The method performed by the radio access network node may further include receiving information identifying a transmit power associated with the aggressor node.

[0184] The configuration information may include at least one of a time division duplex configuration, a beam configuration, and location information associated with transmitters of the plurality of remote radio access network nodes.

[0185] Identifying the aggressor node may include measuring a CLI or a change in CLI associated with at least one candidate aggressor node among the plurality of candidate aggressor nodes while the at least one candidate aggressor node performs a beam sweeping operation or a nulling beam sweeping operation. The method performed by the radio access network node may further include identifying a beam of the aggressor node as a source of the CLI based on the beam sweeping operation or the nulling beam sweeping operation.

[0186] Identifying the aggressor node may further include reporting to the at least one candidate aggressor node a CLI or a change in CLI associated with the at least one candidate aggressor node.

[0187] The beam sweep operation may be performed on at least one of a first set of at least one beam currently being used for data transmission by at least one candidate aggressor node, a second set of at least one beam expected to be used for data transmission by at least one candidate aggressor node, and a third set of at least one beam not being used for data transmission by at least one candidate aggressor node.

[0188] The method performed by the radio access network node may further include configuring at least one resource for measurement of CLI, and determining a level of CLI in a cell of the radio access network node based on a received signal strength of a CLI reference signal received from an aggressor node over the at least one resource.

[0189] The method performed by the radio access network node may further include transmitting beam configuration information of at least one beam of the radio access network node to other radio access network nodes, so as to identify a source beam of the CLI by the other access network nodes.

[0190] The timing of transmitting at least one reference signal for measuring the CLI may be set to coincide with the arrival time of an uplink signal from a user equipment (UE) to another radio access network node and the arrival time of a radio transmission from the radio access network node.

[0191] In the case where downlink transmissions by the radio access network node and the other radio access network node are synchronized, the timing may be set based on a first value representing the arrival time of the uplink signal from the UE and a second value derived based on the distance between the radio access network node and the other radio access network node.

[0192] The method performed by the radio access network node may further include receiving, based on the transmitted at least one reference signal, information indicative of an occurrence of a CLI outside a serving area of ​​the radio access network node.

[0193] The received signal strength value may include at least one of a CLI Channel State Information - Reference Signal Received Power (CLI CSI-RSRP) value and a base station-specific CLI received signal strength indicator (CLI-RSSI) value.

[0194] The CLI CSI-RSRP value may represent a linear average of the power contributions of at least one resource element of one or more antenna ports transmitting a CSI reference signal associated with the CLI RSRP measurement within an associated measurement frequency bandwidth in at least one associated CSI-RS occasion.

[0195] The base station specific CLI-RSSI value may represent a linear average of the total received power observed in at least one Orthogonal Frequency Division Multiplexing (OFDM) symbol of at least one associated measurement time resource in an associated measurement bandwidth from at least one source.

[0196] The at least one source may include at least one of a co-channel serving cell, a non-serving cell, a source of adjacent channel interference, a source of self-interference, and thermal noise.

[0197] The at least one resource may include at least one of: at least one resource for a Zero Power (ZP) Sounding Reference Signal (SRS), at least one punctured resource, at least one ZP CLI management resource, and at least one ZP Channel State Information - Reference Signal (CSI-RS) resource.

[0198] The configuring may include configuring a plurality of ZP SRS resources for measuring respective CLIs caused by wireless transmissions from the plurality of transmitters. Comb coefficients of the plurality of ZP SRS resources may be selected based on a maximum number of the plurality of transmitters, and the determining may be performed based on the comb coefficients and a plurality of orthogonal codes in a code domain for each of the plurality of transmitters.

[0199] The at least one resource may include a plurality of ZP SRS or CSI-RS resources each associated with a different beam, and determining may include determining, for each of the different beams, a respective level of CLI based on a corresponding received signal strength value of a CLI reference signal received through the associated ZP SRS or CSI-RS resource.

[0200] The punctured resources may include at least one of punctured uplink data resources and punctured SRS resources, and the punctured resources may be configured in at least one of a time and a frequency domain.

[0201] The at least one resource may be configured in at least one of a periodic, semi-persistent, and dynamic manner.

[0202] The radio access network node may be configured for Sub-Band Full Duplex (SBFD) operation, and at least one resource may be configured in at least one sub-band.

[0203] The information indicating the occurrence of a CLI may include at least one of a CLI Channel State Information - Reference Signal Received Power (CLI CSI-RSRP) value and a CLI received signal strength indicator (CLI-RSSI) value.

[0204] The information indicating the occurrence of a CLI may be transmitted in at least one of periodic reports, semi-persistent reports, and aperiodic or on-demand reports.

[0205] The method performed by the radio access network node may further include receiving a request to send a report regarding the CLI from another radio access network node or an operation management node acting as a node managing the CLI, and sending a report including information indicating the occurrence of the CLI to the other radio access network node or the operation management node.

[0206] Information indicating the occurrence of a CLI may be sent to a node responsible for CLI management in cases where the level of CLI exceeds an associated threshold.

[0207] Downlink transmissions by the radio access network node and the other radio access network node may be synchronized, in which case the timing of transmitting the uplink signal may be set based on a first value representing the arrival time of the downlink signal from the other radio access network node and a second value derived based on the distance between the radio access network node and the other radio access network node.

[0208] The timing may be based on the UE's timing advance value, which may be a negative number.

[0209] The method performed by the UE may further include configuring the guard period based on the timing.

[0210] Various other modifications will be apparent to those skilled in the art and will not be described in further detail here.

[0211] The whole or part of the above disclosed embodiments can be described as, but not limited to, the following supplementary notes. (Appendix 1) 1. A method performed by a radio access network node, comprising: receiving, from at least one other radio access network node, respective configuration information for determining Cross Link Interference (CLI); identifying an aggressor node as a source of the CLI within a cell of the radio access network node outside the serving area of ​​the aggressor node based on the respective configuration information; A method comprising: (Appendix 2) wherein said identifying is performed by updating a list comprising information identifying at least one candidate aggressor node based on said respective configuration information by including or removing information identifying said at least one other radio access network node; The identifying the aggressor node is performed by identifying the aggressor node from the list. The method described in Appendix 1. (Appendix 3) The updating step includes: location information corresponding to said radio access network node; Respective location information corresponding to the transmitter of the at least one candidate aggressor node; and characteristics of beams corresponding to the transmitters of the at least one candidate aggressor node; is performed based on at least one of The method described in Appendix 2. (Appendix 4) receiving beam configuration information of each of the at least one other radio access network node; The updating is performed based on the respective beam configuration information. 4. The method according to claim 2 or 3. (Appendix 5) and transmitting the list to at least one other node that manages the CLI. 5. The method of any one of appendices 2 to 4. (Appendix 6) receiving a further list including information identifying at least one candidate aggressor node as a source of CLIs for cells of the further radio access network node; updating the list based on the further list; and 6. The method of any one of appendices 2 to 5, further comprising: (Appendix 7) receiving information identifying a transmit power corresponding to the aggressor node; identifying whether transmissions of said aggressor nodes interfere with said access network nodes; 7. The method of any one of appendices 1 to 6, further comprising: (Appendix 8) Each of the configuration information is time division duplex configuration, beam configuration, and location information corresponding to a transmitter of said at least one other radio access network node; Contains at least one of 8. The method of any one of appendices 1 to 7. (Appendix 9) The identifying the aggressor node includes measuring a CLI or a change in CLI corresponding to the at least one candidate aggressor node while the at least one candidate aggressor node is performing a beam sweep operation or a nulling beam sweep operation. 9. The method of any one of appendices 2 to 8. (Appendix 10) Identifying a beam of the aggressor node as a source of the CLI based on the beam sweep operation or the nulling beam sweep operation. 10. The method of claim 9, further comprising: (Appendix 11) The identifying the aggressor node further includes reporting the CLI or a change in the CLI corresponding to the at least one candidate aggressor node to the at least one candidate aggressor node. 11. The method of claim 9 or 10. (Appendix 12) The beam sweep operation is a first set of at least one beam currently being used for data transmission by the at least one candidate aggressor node; a second set of at least one beam expected to be used for data transmission by the at least one candidate aggressor node; and a third set of at least one beam not being used for data transmission by the at least one candidate aggressor node; is performed on at least one of 12. The method of any one of appendices 9 to 11. (Appendix 13) configuring at least one resource for measurement of said CLI; determining a level of the CLI in the cell of the radio access network node based on a received signal strength of a CLI reference signal received from the aggressor node over the at least one resource; 13. The method of any one of appendices 1 to 12, further comprising: (Appendix 14) 1. A method performed by a radio access network node, comprising: detecting, based on a reference signal, occurrences of cross link interference (CLI) caused by radio transmissions from other radio access network nodes outside the serving areas of the other radio access network nodes; transmitting information indicating the occurrence of the CLI to at least one other node that manages the CLI; A method comprising: (Appendix 15) The information indicating the occurrence of the CLI may include: CLI Channel State Information - Reference Signal Received Power (CLI CSI-RSRP) value, and CLI Received Signal Strength Indicator (CLI-RSSI) value Contains at least one of The method described in Appendix 14. (Appendix 16) The information indicating the occurrence of the CLI may include: Periodic reports, semi-persistent reporting, and Aperiodic or on-demand reporting sent on at least one of 16. The method of claim 14 or 15. (Appendix 17) receiving a request from the other radio access network node or an operation management node acting as one of the other at least one node managing the CLI to transmit a report including the information indicating the occurrence of the CLI; sending the report to the other radio access network node or the operation management node; 17. The method of any one of claims 14 to 16, further comprising: (Appendix 18) The information indicating the occurrence of the CLI is transmitted to the at least one other node that manages the CLI in the case where the level of the CLI exceeds a threshold. 18. The method of any one of appendices 14 to 17. (Appendix 19) 1. A method performed by a radio access network node, comprising: configuring at least one resource outside a serving area of ​​a transmitter of the radio access network node for measuring cross link interference (CLI) caused by wireless transmissions from the transmitter; determining a level of the CLI based on a received signal strength value of a CLI reference signal received from the transmitter over the at least one resource; A method comprising: (Appendix 20) The received signal strength value is CLI Channel State Information - Reference Signal Received Power (CLI CSI-RSRP) value, and Base station specific CLI Received Signal Strength Indicator (CLI-RSSI) value Contains at least one of 19. The method described in Appendix 19. (Appendix 21) The CLI CSI-RSRP value represents a linear average of power contributions of at least one resource element of one or more antenna ports transmitting a CSI reference signal associated with the CLI RSRP measurement within an associated measurement frequency bandwidth in at least one associated CSI-RS occasion. 21. The method described in Appendix 20. (Appendix 22) The base station-specific CLI-RSSI value represents a linear average of the total received power observed in at least one Orthogonal Frequency Division Multiplexing (OFDM) symbol of at least one associated measurement time resource in an associated measurement bandwidth from at least one source. 22. The method of claim 20 or 21. (Appendix 23) The at least one source Co-channel serving cell, Non-serving cells, Sources of adjacent channel interference, Sources of self-interference, and Thermal Noise Contains at least one of 23. The method described in Appendix 22. (Appendix 24) The at least one resource is: at least one resource for a Zero Power (ZP) Sounding Reference Signal (SRS); at least one punctured resource, At least one ZP-CLI managed resource, and At least one ZP Channel State Information - Reference Signal (CSI-RS) resource Contains at least one of 24. The method of any one of appendixes 19 to 23. (Appendix 25) The configuring includes configuring a plurality of ZP SRS resources for measuring respective CLIs caused by wireless transmissions from a plurality of transmitters; comb coefficients of the plurality of ZP SRS resources are selected based on a maximum number of the plurality of transmitters; The determining is performed based on the comb coefficients and a plurality of orthogonal codes in the code domain for each of the plurality of transmitters. The method described in Appendix 24. (Appendix 26) the at least one resource includes a plurality of ZP SRS or CSI-RS resources, each associated with a different beam; The determining includes determining, for each of the different beams, a respective level of the CLI based on a corresponding received signal strength value of a CLI reference signal received over the associated ZP SRS or CSI-RS resource. The method described in Appendix 24. (Appendix 27) The punctured resources include at least one of punctured uplink data resources and punctured SRS resources, and the punctured resources are configured in at least one of a time domain and a frequency domain. The method described in Appendix 24. (Appendix 28) the at least one resource is configured in at least one of a periodic, semi-persistent, and dynamic manner; 28. The method of any one of appendices 19 to 27. (Appendix 29) the radio access network node is configured for Sub-Band Full Duplex (SBFD) operation; The at least one resource is configured in at least one subband. 28. The method of claim 24 or 27. (Appendix 30) 1. A method performed by a radio access network node, comprising: transmitting a reference signal outside the serving area of ​​the radio access network node for measuring cross link interference (CLI) caused by radio transmissions from the radio access network node; A method comprising: (Appendix 31) transmitting beam configuration information of at least one beam of the radio access network node to another radio access network node for use in identifying a source beam of the CLI by the other radio access network node; 31. The method of claim 30, further comprising: (Appendix 32) The timing of transmitting the reference signal for measuring CLI is set so that the arrival time of an uplink signal from a user equipment (UE) at another radio access network node coincides with the arrival time of the radio transmission from the radio access network node. 32. The method of claim 30 or 31. (Appendix 33) downlink transmissions by said radio access network node and said other radio access network node are synchronized; The timing is set based on a first value representing the arrival time of the uplink signal from the UE and a second value derived based on a distance between the radio access network node and the other radio access network node. 32. The method described in Appendix 32. (Appendix 34) receiving information indicating an occurrence of a CLI outside a serving area of ​​the radio access network node based on the reference signal; 34. The method of any one of claims 30 to 33, further comprising: (Appendix 35) 1. A method performed by a user equipment (UE), comprising: Transmitting an uplink signal so that the arrival time of the uplink signal at a radio access network node coincides with the arrival time of a reference signal for measuring cross link interference (CLI) from another radio access network node. A method comprising: (Appendix 36) downlink transmissions by said radio access network node and said other radio access network node are synchronized; a timing of transmitting the uplink signal is set based on a first value representing the arrival time of a downlink signal from the other radio access network node and a second value derived based on a distance between the radio access network node and the other radio access network node; The method described in Appendix 35. (Appendix 37) The timing is based on a timing advance value of the UE. 37. The method of claim 35 or 36. (Appendix 38) The timing advance value is a negative number. The method described in Appendix 37. (Appendix 39) configuring a guard period based on said timing; 39. The method of any one of Appendices 36 to 38, further comprising: (Appendix 40) 1. A radio access network node, comprising: means for receiving, from at least one other radio access network node, respective configuration information for determining Cross Link Interference (CLI); means for identifying an aggressor node as a source of the CLI in a cell of the radio access network node outside the serving area of ​​the aggressor node based on the respective configuration information; A radio access network node comprising: (Appendix 41) 1. A radio access network node, comprising: means for detecting, based on a reference signal, occurrence of cross link interference (CLI) caused by radio transmissions from other radio access network nodes outside the serving area of ​​the other radio access network nodes; means for transmitting information indicating the occurrence of the CLI to at least one other node that manages the CLI; A radio access network node comprising: (Appendix 42) 1. A radio access network node, comprising: means for configuring at least one resource outside a serving area of ​​a transmitter of said radio access network node for measuring Cross Link Interference (CLI) caused by radio transmissions from said transmitter; means for determining a level of the CLI based on a received signal strength value of a CLI reference signal received from the transmitter through the at least one resource; A radio access network node comprising: (Appendix 43) 1. A radio access network node, comprising: means for transmitting, outside the serving area of ​​said radio access network node, a reference signal for measuring cross link interference (CLI) caused by radio transmissions from said radio access network node; A radio access network node comprising: (Appendix 44) A user equipment (UE), means for transmitting an uplink signal such that the arrival time of the uplink signal at a radio access network node coincides with the arrival time of a reference signal for measuring cross link interference (CLI) from another radio access network node; A user equipment comprising:

[0212] It will be appreciated by those skilled in the art that many variations and / or modifications may be made to the present disclosure as set forth in the specific examples without departing from the spirit or scope of the disclosure as broadly described. The present examples are, therefore, to be considered in all respects as illustrative and not restrictive.

[0213] This application claims the benefit of priority from UK Patent Application No. 2209320.7 filed on 24 June 2022, the entire contents of which are incorporated herein by reference. [Explanation of symbols]

[0214] 1. Telecommunications Systems 3, 3A, 3B Mobile Devices 5, 5A, 5B, 5C, 5D, 5E base station 7 Core Network 31 Transceiver Circuit 33 Antenna 35 User Interface 37 Controller 39 Memory 41 Operating Systems 43 Communication Control Module 45 CLI Management Module 51 Transceiver circuit 53 Antenna 55 Network Interfaces 57 Controller 59 Memory 61 Operating Systems 63 Communication Control Module 65 CLI Management Module 71 Transceiver Circuit 75 network interfaces 77 Controller 79 Memory 81 Operating Systems 83 Communication Control Module 85 CLI Management Module

Claims

1. 1. A radio access network node, comprising: means for receiving, from at least one other radio access network node, respective configuration information for determining Cross Link Interference (CLI); Each of the configuration information is Subband Full Duplex (SBFD) time-frequency location configuration and Non-Zero Power (NZP) Channel State Information - Reference Signal (CSI-RS) resource configuration; Synchronization Signal / Physical Broadcast Channel (PBCH) Block (SSB) configuration and / or Non-Zero Power (NZP) Channel State Information - Reference Signal (CSI-RS) resource configuration; and location information corresponding to a transmitter of said at least one other radio access network node; at least one of: Radio access network node.

2. 1. A method performed by a radio access network node, comprising: receiving, from at least one other radio access network node, respective configuration information for determining Cross Link Interference (CLI); Each of the configuration information is Subband Full Duplex (SBFD) time-frequency location configuration and Non-Zero Power (NZP) Channel State Information - Reference Signal (CSI-RS) resource configuration; Synchronization Signal / Physical Broadcast Channel (PBCH) Block (SSB) configuration and / or Non-Zero Power (NZP) Channel State Information - Reference Signal (CSI-RS) resource configuration; and location information corresponding to a transmitter of said at least one other radio access network node; Contains at least one of method.

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