Interference mitigation in an integrated access and backhaul network

Abstract

There is provided techniques for interference mitigation in an IAB network. A method is performed by a controller node. The method comprises scheduling transmission from a middle IAB node to a parent IAB node and a child IAB node. The middle IAB node is scheduled to, in a third time resource and upon reception of a first signal from the parent IAB node in a first time resource and reception of a second signal from the child IAB node in a second time resource, simultaneously transmit the first signal to the child IAB node and the second signal to the parent IAB node. The third time resource is determined as a function of the first time resource and the second time resource.

Description

[0001] INTERFERENCE MITIGATION IN AN INTEGRATED ACCESS AND BACKHAUL NETWORK

[0002] TECHNICAL FIELD

[0003] Embodiments presented herein relate to methods, a controller node, integrated access and backhaul nodes, computer programs, and a computer program product for interference mitigation in an integrated access and backhaul network.

[0004] BACKGROUND

[0005] In general terms, network densification via the deployment of network access points (such as macro base stations, micro base stations, or pico base stations) is one of mechanism that can be employed to address the ever-increasing demand for more and more bandwidth / capacity in wireless networks. Due to the availability of more spectrum in the millimeter wave (mmW) band, deploying small cells that operate in this band is an attractive deployment option for these purposes. However, deploying fiber connections to each of the network access points, which is the usual way in which small cells are deployed, can end up being very expensive and impractical. Thus, employing a wireless link for connecting the small cells to the wireless network is a cheaper and practical alternative with more flexibility. One such technology is an Integrated Access and Backhaul (IAB) network, where the network operator can utilize part of the radio resources for wireless access links and part of the radio resources for wireless backhaul links.

[0006] In Fig. 1 is illustrated an IAB network 100 where multiple hops (i.e., multiple wireless backhaul links) are supported. For illustrative purposes, the IAB network 100 comprises three IAB nodes 110, 120, 130. An IAB donor node (or in short IAB donor) 110 has a wired or wireless connection to the core network 140 (which in turn is operatively connected to a data network 150). The IAB nodes 120, 130 can be wirelessly connected using some cellular air interface technology, such as the New Radio (NR) air interface to the IAB donor 110, either directly (as for IAB node 120) or indirectly via another IAB node (as for IAB node 130). The connection between an IAB node 110, 120, 130 and its served pieces of user equipment (UEs) 160a, 160b, 160c are referred to as downlink (DL) and uplink (UL) access links, whereas the connections between two IAB nodes are referred to as wireless backhaul links. The adjacent upstream IAB node which is closer to the IAB donor node of a given IAB node is referred to as a parent IAB node of that given IAB node. The IAB node can also be referred to as a parent IAB node. The adjacent downstream IAB node which is further away from the IAB donor node of a given IAB node is referred to as a child IAB node of that given IAB node. In the example of Fig. 1, IAB node (i.e., the donor node) 110 is the parent IAB node of IAB node 120 and IAB node 130 is the child IAB node of IAB node 120. The wireless backhaul links between a given IAB node and its parent IAB node are referred to as DL and UL parent backhaul (BH) links, whereas the backhaul links between a given IAB node and its child IAB node are referred to as DL and UL child BH links.

[0007] In Fig. 2 is illustrated an IAB network 200 with the same components as in Fig. 1 but illustrated from an IAB architecture point-of-view. Hence, the IAB network 200 comprises three IAB nodes 210, 220, 230 connected to a data network 250 via a core network 240 and configured to serve UEs 2601, 260b, 260c. The connection to the core network 24 is via the NG interface and the connections to the UEs are via the NR Uu interface. Further, the IAB nodes communicate with each other over the F1 interface. The IAB architecture is illustrated as adopting a Central-Unit / Distributed-Unit (DU / DU) split. Time-critical functionalities are realized in the DU closer to the radio. Less time-critical functionalities are pooled in the CU with the opportunity for centralization. Based on this architecture, an IAB donor 210 contains both CU and DU functions. In particular, it contains all CU functions of the IAB nodes under the same IAB donor. Each remaining IAB node 220, 230 then hosts the DU function(s) of an access network node. In order to be able to transmit / receive wireless signals to / from the upstream IAB node or the IAB donor, each IAB node 220, 230 has a mobile termination (MT) interface. The MT interface can be regarded as being a logical unit providing a necessary set of UE-like functions. Via the DU, the IAB nodes 220, 230 can establish a radio link control (RLC) channel to UEs and / or to MT interfaces of the connected IAB node(s). Via the MT interface 220, 230, the IAB nodes can establish a backhaul radio interface towards the serving IAB node or IAB donor.

[0008] Wireless backhaul links can be vulnerable to blockage, e.g., due to moving objects, such as vehicles, due to seasonal changes (foliage), severe weather conditions (rain, snow, or hail, etc.), or due to infrastructure changes (new buildings, etc.). Such vulnerability also applies to IAB nodes. Also, traffic variations can create uneven load distribution on wireless backhaul links, leading to local link or node congestion. In view of those concerns, the IAB networks 100, 200 can support redundant paths, for example using network topologies based on spanning trees (STs) or directed acyclic graphs (DAGs). This means that any given IAB node can have multiple child IAB nodes and / or multiple parent IAB nodes. The multi-connectivity or route redundancy may be used for back-up purposes. It is also possible that redundant routes are used concurrently, e.g., to achieve load balancing, reliability, etc.

[0009] In case of in-band operation, the IAB nodes may be subject to a half-duplex constraint, where each of the IAB nodes can only be in either transmission mode or reception mode at a time. In this respect, in Release 16 (Rel-16) of the third-generation partnership project (3GPP) suite of standards for telecommunication, time-division multiplexing (TDM) is mostly considered for IAB networks, where the MT and DU resources of the same IAB node are separated in time. However, in Release 17 (Rel-17), enhancements of IAB networks have been introduced. One enhancement is the specification of enhancements to the resource multiplexing between child and parent links of an IAB node, including support of simultaneous operation (transmission and / or reception) of the IAB node's child and parent links. The cases with usage of the MT interface and the DU interface for simultaneous transmission and reception are commonly referred to as full-duplex IAB. Another case is where the IAB node at one time can use its MT interface and DU interface for simultaneous transmission and at another time use its MT interface and DU interface for simultaneous reception. This is schematically illustrated in Fig. 3. In Fig. 3 is schematically illustrated an IAB network 300a, 300b, where, at a first time instant, an IAB node 320 is using its MT interface for receiving a first signal X1 from one IAB node 310 and its DU interface for receiving a second signal X2 from another IAB node 330. Then, at a second time instant, the IAB node 320 is using its MT interface for transmitting the second signal X2 to IAB node 310 and its DU interface for transmitting the first signal X1 to IAB node 330. However, with simultaneous transmission from the MT interface and the DU interface of the same IAB node 320, there is high probability for strong interferences to the other IAB nodes 310, 330, as illustrated by the channel components H1 and H2 in Fig. 3. This may affect the performance of both IAB nodes 310, 330 and also result in error propagation in the multi-hop chain.

[0010] The above examples show that there is a need for means to handle interference in IAB networks.

[0011] SUMMARY

[0012] An object of embodiments herein is to address the above issues by providing means for handling interference in IAB networks.

[0013] A particular object is to reduce the interference in an IAB network where one of the IAB nodes is simultaneously transmitting to two other nodes in the IAB network.

[0014] A particular object is to reduce the interference by proper scheduling of the transmissions from the IAB node that is simultaneously transmitting to two other nodes in the IAB network.

[0015] The herein disclosed aspects are based on interference mitigation in an IAB network. The IAB network comprises at least a parent IAB node, a middle IAB node and a child IAB node. In some of the aspects, one of the parent IAB node and the child IAB node will be referred to as a first IAB node whereas the other of the parent IAB node and the child IAB node can be referred to as a third IAB node. The IAB nodes are controlled by a controller node.

[0016] According to a first aspect there is presented a method for interference mitigation in an IAB network. The IAB network comprises at least a parent IAB node, a middle IAB node and a child IAB node. The method is performed by a controller node of the IAB network. The method comprises scheduling transmission from the middle I AB node to the parent I AB node and the child I AB node. The middle I AB node is scheduled to, in a third time resource and upon reception of a first signal from the parent I AB node in a first time resource and reception of a second signal from the child I AB node in a second time resource, simultaneously transmit the first signal to the child IAB node and the second signal to the parent IAB node. The third time resource is determined as a function of the first time resource and the second time resource. The method comprises providing information to the parent IAB node for the parent IAB node to, in the third time resource, receive the second signal and the child IAB node to, in the third time resource, receive the first signal.

[0017] According to a second aspect there is presented a controller node for interference mitigation in an IAB network. The IAB network comprises at least a parent IAB node, a middle IAB node and a child IAB node. The controller node comprises processing circuitry. The processing circuitry is configured to cause the controller node to schedule transmission from the middle IAB node to the parent IAB node and the child IAB node. The middle IAB node is scheduled to, in a third time resource and upon reception of a first signal from the parent IAB node in a first time resource and reception of a second signal from the child IAB node in a second time resource, simultaneously transmit the first signal to the child IAB node and the second signal to the parent IAB node. The third time resource is determined as a function of the first time resource and the second time resource. The processing circuitry is configured to cause the controller node to provide information to the parent IAB node for the parent IAB node to, in the third time resource, receive the second signal and the child IAB node to, in the third time resource, receive the first signal.

[0018] According to a third aspect there is presented a computer program for interference mitigation in an IAB network. The computer program comprises computer program code which, when run on processing circuitry of a controller node, causes the controller node to perform actions. One action comprises the controller node to schedule transmission from the middle IAB node to the parent IAB node and the child IAB node. The middle IAB node is scheduled to, in a third time resource and upon reception of a first signal from the parent IAB node in a first time resource and reception of a second signal from the child IAB node in a second time resource, simultaneously transmit the first signal to the child IAB node and the second signal to the parent IAB node. The third time resource is determined as a function of the first time resource and the second time resource. One action comprises the controller node to provide information to the parent IAB node for the parent IAB node to, in the third time resource, receive the second signal and the child IAB node to, in the third time resource, receive the first signal.

[0019] According to a fourth aspect there is presented a method for interference mitigation in an IAB network. The IAB network comprises at least a parent IAB node, a middle IAB node and a child IAB node. The method is performed by the middle IAB node. The method comprises receiving, in a first time resource, a first signal from the parent IAB node and, in a second time resource, a second signal from the child IAB node. The method comprises receiving, from a controller node of the IAB network, scheduling of transmission from the middle IAB node to the parent IAB node and the child IAB node, wherein, according to the scheduling, the middle IAB node is scheduled to, in a third time resource, simultaneously transmit the first signal to the child IAB node and the second signal to the parent IAB node. The third time resource is determined as a function of the first time resource and the second time resource. The method comprises transmitting, in the third time resource. The first signal to the child IAB node and the second signal to the parent IAB node.

[0020] According to a fifth aspect there is presented a middle IAB node for interference mitigation in an IAB network. The IAB network comprises at least a parent IAB node. The middle IAB node and a child IAB node. The middle IAB node comprises processing circuitry. The processing circuitry is configured to cause the middle IAB node to receive, in a first time resource, a first signal from the parent IAB node and, in a second time resource, a second signal from the child IAB node. The processing circuitry is configured to cause the middle IAB node to receive, from a controller node of the IAB network, scheduling of transmission from the middle IAB node to the parent IAB node and the child IAB node, wherein, according to the scheduling, the middle IAB node is scheduled to, in a third time resource, simultaneously transmit the first signal to the child IAB node and the second signal to the parent IAB node. The third time resource is determined as a function of the first time resource and the second time resource. The processing circuitry is configured to cause the middle IAB node to transmit, in the third time resource. The first signal to the child IAB node and the second signal to the parent IAB node.

[0021] According to a sixth aspect there is presented a computer program for interference mitigation in an IAB network. The computer program comprises computer program code which, when run on processing circuitry of a middle IAB node, causes the middle IAB node to perform actions. One action comprises the middle IAB node to receive, in a first time resource, a first signal from the parent IAB node and, in a second time resource, a second signal from the child IAB node. One action comprises the middle IAB node to receive, from a controller node of the IAB network, scheduling of transmission from the middle IAB node to the parent IAB node and the child IAB node, wherein, according to the scheduling, the middle IAB node is scheduled to, in a third time resource, simultaneously transmit the first signal to the child IAB node and the second signal to the parent IAB node. The third time resource is determined as a function of the first time resource and the second time resource. One action comprises the middle IAB node to transmit, in the third time resource. The first signal to the child IAB node and the second signal to the parent IAB node. According to a seventh aspect there is presented a method for interference mitigation in an I AB network. The I AB network comprises at least a first I AB node, a middle I AB node and a third I AB node. The method is performed by the first I AB node. The method comprises transmitting, in a first time resource, either a first signal or a second signal towards the third I AB node via the middle I AB node. The method comprises receiving information from the controller node for the I AB node to, in the third time resource, receive the other of the first signal and the second signal. The method comprises receiving, in a third time resource, this other of the first signal and the second signal from the third I AB node via the middle I AB node. This other of the first signal and the second signal is transmitted from the third I AB node in a second time resource. The third time resource is determined as a function of the first time resource and the second time resource.

[0022] According to an eighth aspect there is presented a first I AB node for interference mitigation in an I AB network. The I AB network comprises at least the first I AB node, a middle I AB node and a third I AB node. The first IAB node comprises processing circuitry. The processing circuitry is configured to cause the first IAB node to transmit, in a first time resource, a first signal towards the third IAB node via the middle IAB node. The processing circuitry is configured to cause the first IAB node to receive information from the controller node for the IAB node to, in the third time resource, receive a second signal. The processing circuitry is configured to cause the first IAB node to receive, in a third time resource, the second signal from the third IAB node via the middle IAB node. The second signal is transmitted from the third IAB node in a second time resource. The third time resource is determined as a function of the first time resource and the second time resource.

[0023] According to a ninth aspect there is presented a computer program for interference mitigation in an IAB network, the computer program comprising computer program code which, when run on processing circuitry of a first IAB node, causes the first IAB node to perform actions. One action comprises the first IAB node to transmit, in a first time resource, a first signal towards the third IAB node via the middle IAB node. One action comprises the first IAB node to receive information from the controller node for the IAB node to, in the third time resource, receive a second signal. One action comprises the first IAB node to receive, in a third time resource, the second signal from the third IAB node via the middle IAB node. The second signal is transmitted from the third IAB node in a second time resource. The third time resource is determined as a function of the first time resource and the second time resource.

[0024] According to a tenth aspect there is presented a computer program product comprising a computer program according to at least one of the third aspect, the sixth aspect, and the ninth aspect and a computer readable storage medium on which the computer program is stored. The computer readable storage medium can be a non-transitory computer readable storage medium. Advantageously, these aspects provide means for handling interference in IAB networks.

[0025] An object of embodiments herein is to address the above issues by providing means for handling interference in IAB networks.

[0026] Advantageously, these aspects enable interference to be reduced in an IAB network where one of the IAB nodes is simultaneously transmitting to two other IAB nodes in the IAB network. This is one of the main challenges of IAB networks with simultaneous operation. In turn, reducing the interference improves the probability of successful decoding, thereby reducing the need for hybrid automatic repeat request (HARQ) based retransmissions and, therefore, reduces the end-to-end transmission delay and use of network resources otherwise needed for retransmissions.

[0027] Advantageously, these aspects enable the interference to be reduced by proper scheduling of the transmissions from the IAB node that is simultaneously transmitting to two other nodes in the IAB network.

[0028] Advantageously, these aspects enable beamforming to be more flexible, since wider / more beams can be used by the IAB nodes without the risk of causing interference.

[0029] Other objectives, features and advantages of the enclosed embodiments will be apparent from the following detailed disclosure, from the attached dependent claims as well as from the drawings.

[0030] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a / an / the element, apparatus, component, means, module, step, etc." are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, module, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.

[0031] BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The inventive concept is now described, by way of example, with reference to the accompanying drawings, in which:

[0033] Figs. 1 , 2, and 3 are schematic diagrams illustrating IAB networks according to examples;

[0034] Figs. 4, 5, and 6 are flowcharts of methods according to embodiments;

[0035] Fig. 7 is a schematic diagram illustrating an I AB network according to an embodiment; Fig. 8 is a schematic diagram showing structural units of a controller node according to an embodiment;

[0036] Fig. 9 is a schematic diagram showing structural units of a middle I AB node according to an embodiment;

[0037] Fig. 10 is a schematic diagram showing structural units of a first IAB node according to an embodiment; and

[0038] Fig. 11 shows one example of a computer program product comprising computer readable means according to an embodiment.

[0039] DETAILED DESCRIPTION

[0040] The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments of the inventive concept are shown. This inventive concept may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. Like numbers refer to like elements throughout the description. Any step or feature illustrated by dashed lines should be regarded as optional.

[0041] As disclosed above, the examples in the background section show that there is a need for means to handle interference in IAB networks.

[0042] According to at least some of the herein disclosed embodiments, technologies are developed for interference handling in IAB networks where simultaneous operation as in Fig. 3 is used. In this respect, it is here noted that the signals X1 and X2 might not be transmitted at the same time from IAB nodes 310, 330. Rather, as will be disclosed in further detail below, the signal X1 is transmitted in a first time resource N1 and the signal X2 is transmitted in a second time resource N2, where the time resources N1, N2, might be either the same or different time resources, as in Fig. 7. The herein disclosed embodiments are based on proper scheduling and coordination between the different IAB nodes in the IAB network. The IAB network 100, 200, 300a, 300b comprises at least a parent IAB node 110, 210, 310, a middle IAB node 120, 220, 320, and a child IAB node 130, 230, 330. In some of the aspects, one of the parent IAB node and the child IAB node will be referred to as a first IAB node whereas the other of the parent IAB node and the child IAB node can be referred to as a third IAB node. Further, as will be disclosed in further detail below, generally the child IAB node 130, 230, 330 might even be a UE. However, the term "child IAB node” will be used throughout for consistency purposes. The IAB nodes 110, 120, 130, 210, 220, 230, 310, 320, 330 are controlled by a controller node 170, 270. The controller node 170, 270 might be collocated with, integrated with, or part of, one of: the parent IAB node 110, 210, 310, the middle IAB node 120, 220, 320, a donor IAB node 110, 210 in the IAB network 100, 200, 300a, 300b, a core network node. Further, the controller node 170, 270 might have a distributed implementation, where part of the controller node 170, 270 is implemented in one of the IAB nodes and another part of the controller node 170, 270 is implemented in another one of the IAB nodes, etc. In this respect, with reference again to Figs. 1 and 2, the controller node 170, 270 of the middle IAB node may be provided in the parent IAB node, and the controller node 170, 270 of the child IAB node may be provided in the middle IAB node. However, the parent IAB node cannot comprise the controller node 170, 270 of the child IAB node, unless the parent IAB node is the donor node. Further, the middle IAB node 120, 220, 320 cannot comprise the controller node 170, 270 of the parent IAB node 110, 210, 310.

[0043] It is assumed that one IAB node (the middle IAB node 120, 220, 320) receives signals X1, X2 (either using TDM or simultaneous reception) from two other IAB nodes (the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330).

[0044] It is further assumed that the controller node 170, 270 is configured to provide coordination between the parent IAB node 110, 210, 310 and the middle IAB node 120, 220, 320 and / or between the middle IAB node 120, 220, 320 and the child IAB node 130, 230, 330 about the transmission of the signals X1, X2 to be transmitted by the middle IAB node 120, 220, 320 simultaneously to the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330 at specific time slots.

[0045] It is further assumed that the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330 are configured to exploit the received information to adapt the decoding scheme and thereby remove, or at least mitigate or suppress, the interference.

[0046] Reference is now made to Fig. 4 illustrating a method for interference mitigation in an IAB network 100, 200, 300a, 300b as performed by the controller node 170, 270 according to an embodiment.

[0047] S108: The controller node 170, 270 schedules transmission from the middle IAB node 120, 220, 320 to the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330.

[0048] The middle IAB node 120, 220, 320 is scheduled to, in a third time resource N3 and upon reception of a first signal X1 from the parent IAB node 110, 210, 310 in a first time resource N1 and reception of a second signal X2 from the child IAB node 130, 230, 330 in a second time resource N2, simultaneously transmit the first signal X1 to the child IAB node 130, 230, 330 and the second signal X2 to the parent IAB node 110, 210, 310, and The third time resource N3 is determined as a function of the first time resource N1 and the second time resource N2.

[0049] S110: The controller node 170, 270 provides information to the parent I AB node for the parent IAB node 110, 210, 310 to, in the third time resource N3, receive the second signal X2 and the child IAB node 130, 230, 330 to, in the third time resource N3, receive the first signal X1.

[0050] In this respect, the controller node of the parent IAB node might schedule the middle IAB node for the middle IAB node to send a signal to the parent IAB node (in this case: the second signal X2). Likewise, the controller node of the child IAB node might schedule the child IAB node to receive a signal from the middle IAB node (in this case: the first signal X1). Further, the controller node(s) might inform the parent IAB node and the child IAB node about the signals that are transmitted (i.e., that the second signal X2 is transmitted by the middle IAB node to the parent IAB node in the third time resource N3, and that the first signal X1 is transmitted by the middle IAB node to the child IAB node in the third time resource N3). Further, the controller node(s) might inform the parent IAB node and the child IAB node about the relation between the signals (i.e., that the second signal X2 transmitted by the middle IAB node to the parent IAB node in the third time resource N3 is with the same as the second signal X2 transmitted by the child IAB node to the middle IAB node in the second time resource N2 and possibly impacted by interference by the first signal X1, and that the first signal X1 transmitted by the middle IAB node to the child IAB node in the third time resource N3 is the same as the first signal X1 transmitted by the parent IAB node to the middle IAB node in the first time resource N1 and possibly impacted by interference by the second signal X2) so that the parent IAB node and the child IAB can apply the proper decoding and interference suppression accordingly, see below.

[0051] Embodiments relating to further details of interference mitigation in an IAB network 100, 200, 300a, 300b as performed by the controller node 170, 270 will now be disclosed with continued reference to Fig. 4.

[0052] In some aspects, the controller node 170, 270 configures the middle IAB node 120, 220, 320 for transmission of the first signal X1 and the second signal X2 in the third time resource N3, and configures the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330 for reception of the signals in the third time resource N3. Therefore, in some embodiments, the controller node 170, 270 is configured to perform (optional) step S102.

[0053] S102: The controller node 170, 270 provides transmission configuration to the middle IAB node 120, 220, 320 for use when transmitting the first signal X1 and the second signal X2, and reception configuration to the parent IAB node 110, 210, 310 for use when receiving the second signal X2 and to the child IAB node 130, 230, 330 for use when receiving the first signal X1.

[0054] In some non-limiting examples, the transmission configuration pertains to at least one of enabling simultaneous transmission, transmit beam configuration (e.g., at the MT interface and the DU interface), transmission power (of the MT interface and the DU interface), frequency bandwidth (to be used for simultaneous operation), modulation and coding scheme (of the first and the second signals), indication a specific set of restricted transmission beams, etc.

[0055] In this respect, there may be a set of restricted beams, i.e., a set of beams at the MT interface and the DU interface, which cannot be used simultaneously by the MT interface and the DU interface.

[0056] According to the herein disclosed embodiments, where proper coordination and scheduling enables the parent IAB node 110, 210, 310 and / or the child IAB node 130, 230, 330 to mitigate the interference, a different set of restricted beams may be considered, where more combinations of beams can be used by the MT interface and the DU interface for simultaneous transmission. Also, given that the parent IAB node 110, 210, 310 and / or the child IAB node 130, 230, 330 can mitigate the interference, the effective signal to interference plus noise ratio (SINR) increases and, therefore, higher modulation and coding may be considered by the middle IAB node 120, 220, 320 for simultaneous transmission.

[0057] In some non-limiting examples, the reception configuration pertains to at least one of: receive beam configuration, interference suppression scheme, indicating a limited set of restricted receive beams, etc.

[0058] In some aspects, the controller node 170, 270 obtains capability reports about the different IAB nodes. Therefore, in some embodiments, the controller node 170, 270 is configured to perform (optional) step S104.

[0059] S104: The controller node 170, 270 receives a capability report from at least one of the middle IAB node 120, 220, 320, the parent IAB node 110, 210, 310, and the child IAB node 130, 230, 330.

[0060] In some non-limiting examples, the capability report comprises information pertaining to at least one of the middle IAB node 120, 220, 320, the parent IAB node 110, 210, 310, and the child IAB node 130, 230, 330 with respect to at least one of: capabilities for simultaneous transmission and / or simultaneous transmission, beamforming capabilities (in the MT and DU part of the IAB nodes, such as the type (wide, semi-wide, narrow) of beams, number of beams, beams directions, etc.), power allocation capabilities (in the MT interface and / or DU interface of the IAB node), dynamic range capabilities, interference suppression capabilities, number, type, and constellations, of antennas, type of IAB node (wide-area or local-area), etc. It is here noted that the interference suppression capabilities are only relevant for the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330. The capability reports may be received via medium access control (MAC) control element (CE), via radio resource control (RRC) signaling, etc. Further, the capability reports may be received from one or more of: the parent IAB node 110, 210, 310, the child IAB node 130, 230, 330, the middle IAB node 120, 220, 320, the IAB donor, an Operations, Administration and Maintenance (0AM) node, etc.

[0061] In some aspects, the controller node 170, 270 also schedules the parent IAB node 110, 210 and the child IAB node 130, 230, 330. Therefore, in some embodiments, the controller node 170, 270 is configured to perform (optional) step S106.

[0062] S106: The controller node 170, 270 schedules the parent IAB node 110, 210, 310 to, in the first time resource N 1 , transmit the first signal X1, and the child IAB node 130, 230, 330 to, in the second time resource N2, transmit the second signal X2.

[0063] In other aspects, the scheduling of the first signal X1 in the first time resource N1 and of the second signal X2 in the second time resource N2 is performed by some central scheduling entity in the IAB network 100, 200, 300a, 300b. But then at least the controller node 170, 270 is made aware of the scheduling of the parent IAB node 110, 210 and the scheduling of the child IAB node 130, 230, 330.

[0064] Further, the transmission configuration of the middle IAB node 120, 220, 320, the reception configuration of the parent IAB node 110, 210, 310 and / or the child IAB node 130, 230, 330, and / or the scheduling configuration (as in steps S106, S108 and S110) may be dynamic, periodic or semi- persistent. Also, the signaling for the transmission configuration, for the reception configuration, and / or the scheduling configuration can be based on downlink control information (DCI), a MAC-CE or RRC signaling.

[0065] There can be different ways for the third time resource N3 to be determined. Different embodiments relating thereto will now be described in turn.

[0066] In general terms, scheduling the middle IAB node 120, 220, 320 for simultaneous transmission of the first signal X1 and the second signal X2 in the third time resource N3 can be based on the DL and / or UL data traffic in the IAB network 100, 200, 300a, 300b, quality-of-service requirements for the signals X1, X2, channel quality (of the channel between the middle IAB node 120, 220, 320 and the parent IAB node 110, 210, 310 and of the channel between the middle IAB node 120, 220, 320 and the child IAB node 130, 230, 330), buffering capabilities of the IAB nodes, etc. Hence, in some embodiments, the third time resource N3 further is determined as a function of the information comprised in the capability report. That is, in some non-limiting examples, the third time resource N3 further is determined as a function of at least one of: downlink and / or uplink data traffic in the IAB network 100, 200, 300a, 300b, quality-of-service requirements in the IAB network 100, 200, 300a, 300b, channel quality in the IAB network 100, 200, 300a, 300b, decoding capabilities of the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330, the buffering capability / status of the middle IAB node 120, 220, 320.

[0067] In further examples, scheduling the middle IAB node 120, 220, 320 for simultaneous transmission of the first signal X1 and the second signal X2 in the third time resource N3 can be based on the capability reports (for example in terms of power levels to be middle IAB node 120, 220, 320, the decoding capabilities and interference cancellation capabilities of the the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330). That is, in some embodiments, the third time resource N3 is further determined as a function of the information comprised in the capability report.

[0068] In some embodiments, the function according to which the third time resource N3 is determined, specifies the third time resource N3 to have an offset to the first time resource N1 and the second time resource N2. In particular, in some embodiments, according to the function, the third time resource N3 has an offset to the first time resource N1 and the second time resource N2. For example, the third time resource N3 can be determined by selecting the offset from a predetermined set of fixed values. These values can either be explicitly indicated by the controller node 170, 270 to the middle IAB node 120, 220, 320 (in step S108) and to the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330 (in step S110), or be implicitly indicated in these steps as an index referring to a tabulated (and thus pre-configured) value.

[0069] As disclosed above, the middle IAB node 120, 220, 320 may receive the signals X1, X2 either using TDM or simultaneous reception from the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330.

[0070] Thus, in case of TDM, each of the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330 is allocated different time resources for transmission. That is, in some embodiments, the first time resource N1 is different from the second time resource N2. Then, the third time resource N3 can be determined to have an offset with respect to the first time resource N1 and the second time resource N2 occurring latest in time, i.e., max{N1,N2}. That is, in some embodiments, according to the function, the third time resource N3 is determined as max{N1,N2}+K, where N1 is the first time resource and N2 is the second time resource, and where K>0 is an integer (that is the aforementioned offset).

[0071] Further, in case of simultaneous reception, the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330 are both allocated the same time resources for transmission. That is, in some embodiments, the first time resource N1 and the second time resource N2 are both equal to a common time resource. Then, the third time resource N3 can be determined to have an offset with respect to either the first time resource N1 or the second time resource N2 (since N1 = N2 = N). That is, in some embodiments, according to the function, the third time resource N3 is determined as N+K, where N is the common time resource, and where K>0 is an integer (that is the aforementioned offset).

[0072] Reference is now made to Fig. 5 illustrating a method for interference mitigation in an IAB network 100, 200, 300a, 300b as performed by the middle IAB node 120, 220, 320 according to an embodiment.

[0073] S206: The middle IAB node 120, 220, 320 receives, in a first time resource N1, a first signal X1 from the parent IAB node 110, 210, 310 and, in a second time resource N2, a second signal X2 from the child IAB node 130, 230, 330.

[0074] S208: The middle IAB node 120, 220, 320 receives, from a controller node 170, 270 of the IAB network 100, 200, 300a, 300b, scheduling of transmission from the middle IAB node 120, 220, 320 to the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330.

[0075] According to the scheduling, the middle IAB node 120, 220, 320 is scheduled to, in a third time resource N3, simultaneously transmit the first signal X1 to the child IAB node 130, 230, 330 and the second signal X2 to the parent IAB node 110, 210, 310. The third time resource N3 is determined as a function of the first time resource N1 and the second time resource N2.

[0076] The principles disclosed above with respect to the implementation of the controller node and with respect to the flowchart of Fig. 4 apply here as well. In this respect, the controller node of the middle IAB node might decide that the signals the middle IAB node received are to be forwarded, relayed, or passed on, to the parent IAB node and the child IAB node (i.e. , that the second signal X2 is to be transmitted by the middle IAB node to the parent IAB node in the third time resource N3, and that the first signal X1 is to be transmitted by the middle IAB node to the child IAB node in the third time resource N3). The controller node of the middle IAB node might then inform the parent IAB node and the child IAB node about the signals that are to be transmitted, and about the time resource in which these signals are to be transmitted, in the same manner as disclosed above with reference to the flowchart of Fig. 4.

[0077] Thus, the middle IAB node 120, 220, 320 is scheduled to, upon having received the first and the second signals X1, X2, transmit the first and the second signals X1, X2 to the child IAB node 130, 230, 330 and the parent IAB node 110, 210, 310, respectively, via simultaneous operation.

[0078] S210: The middle IAB node 120, 220, 320 transmits, in the third time resource N3, the first signal X1 to the child IAB node 130, 230, 330 and the second signal X2 to the parent IAB node 110, 210, 310. Embodiments relating to further details of interference mitigation in an IAB network 100, 200, 300a, 300b as performed by the middle IAB node 120, 220, 320 will now be disclosed with continued reference to Fig. 5.

[0079] In accordance with the example in Fig. 2, the middle IAB node 120, 220, 320 comprises an MT interface, and a DU interface. The first signal X1 is then received via the MT interface, whereas the second signal X2 is received via the DU interface. Further, the first signal X1 is transmitted via the DU interface, whereas the second signal X2 is transmitted via the MT interface.

[0080] In further accordance with the example in Fig. 2, the middle IAB node 120, 220, 320 is downstream the parent IAB node 110, 210, 310 and upstream the child IAB node 130, 230, 330.

[0081] As disclosed above, in some aspects, the controller node 170, 270 configures the middle IAB node 120, 220, 320 for transmission of the first signal X1 and the second signal X2 in the third time resource N3. Therefore, in some embodiments, the middle IAB node 120, 220, 320 is configured to perform (optional) step S202.

[0082] S202: The middle IAB node 120, 220, 320 receives transmission configuration from the controller node 170, 270 for the middle IAB node 120, 220, 320 to use when transmitting the first signal X1 and the second signal X2.

[0083] As further disclosed above, in some non-limiting examples, the transmission configuration pertains to at least one of enabling simultaneous transmission, transmit beam configuration, transmission power, frequency bandwidth, modulation and coding scheme.

[0084] As yet further disclosed above, the controller node 170, 270 might obtain capability reports about the different IAB nodes. The middle IAB node 120, 220, 320 might be configured to transmit such a capability report. Therefore, in some embodiments, the middle IAB node 120, 220, 320 is configured to perform (optional) step S204.

[0085] S204: The middle IAB node 120, 220, 320 sends a capability report to the controller node 170, 270.

[0086] As further disclosed above, in some non-limiting examples, the capability report comprises information pertaining to at least one of: capabilities for simultaneous transmission and / or simultaneous transmission, beamforming capabilities, power allocation capabilities, dynamic range capabilities, interference suppression capabilities, number, type, and constellations, of antennas. The third time resource N3 might then further be determined as a function of the information comprised in the capability report. As disclosed in step S206, the middle IAB node 120, 220, 320 receives, in a first time resource N1, a first signal X1 from the parent IAB node 110, 210, 310 and, in a second time resource N2, a second signal X2 from the child IAB node 130, 230, 330. These signals may have been transmitted using TDM or simultaneous reception from the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330.

[0087] As disclosed above, there can be different ways for the third time resource N3 to be determined. Different embodiments relating thereto will now be described in turn.

[0088] In case of TDM, each of the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330 is allocated different time resources for transmission. The middle IAB node 120, 220, 320 will then receive the first signal X1 and the second signal X2 in different time resources. That is, in some embodiments, the first time resource N1 is different from the second time resource N2. Then, as disclosed above, the third time resource N3 can be determined to have an offset with respect to the first time resource N1 and the second time resource N2 occurring latest in time, i.e., max{N1,N2}. That is, in some embodiments, according to the function, the third time resource N3 is determined as max{N1,N2}+K, where N1 is the first time resource and N2 is the second time resource, and where K>0 is an integer (that is the aforementioned offset).

[0089] In case of simultaneous reception, the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330 are both allocated the same time resources for transmission. The middle IAB node 120, 220, 320 will then receive the first signal X1 and the second signal X2 in the same time resource. Hence, in some embodiments, the first time resource N1 and the second time resource N2 are both equal to a common time resource.

[0090] With simultaneous transmission of the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330 (at time resource N1 = N2 = N), the simultaneous transmission of the first signal X1 and the second signal X2 by the middle IAB node 120, 220, 320 can be in a time resource N+K. That is, in some embodiments, according to the function, the third time resource N3 is determined as N+K, where N is the common time resource, and where K>0 is an integer (that is the aforementioned offset).

[0091] As disclosed above, the offset can be selected from a predetermined set of fixed values. These values can either be explicitly indicated by the controller node 170, 270 to the middle IAB node 120, 220, 320 (and thus received in step S208), or be implicitly indicated in this step as an index referring to a tabulated (and thus pre-configured) value.

[0092] Reference is now made to Fig. 6 illustrating a method for interference mitigation in an IAB network 100, 200, 300a, 300b as performed by the first IAB node 1000 according to an embodiment. As disclosed above, the first IAB node could be either the parent IAB node 110, 210, 310 or the child IAB node 130, 230, 330. As further disclosed above, in case the first IAB node is the parent IAB node 110, 210, 310, then a third IAB node is the child IAB node 130, 230, 330, and vice versa.

[0093] S308: The first IAB node transmits, in a first time resource N1, N2, either a first signal X1 or a second signal X2 towards the third IAB node via the middle IAB node 120, 220, 320.

[0094] S312: The first IAB node receives information from the controller node 170, 270 for the first IAB node to, in the third time resource N3, receive another of the first signal X1 and the second signal X2.

[0095] That is, if the first signal X1 was transmitted in step S308, then, the scheduling in S312, and the reception in step S314, is of the second signal X2. Likewise, if instead the second signal X2 was transmitted in step S308, then, the scheduling in S312, and the reception in step S314, is of the first signal X1.

[0096] S314: The first IAB node receives, in a third time resource N3, the other of the first signal X1 and the second signal X2 from the third IAB node via the middle IAB node 120, 220, 320. Said other of the first signal X1 and the second signal X2 is transmitted from the third IAB node in a second time resource N2, N1. The third time resource N3 is determined as a function of the first time resource N1, N2 and the second time resource N2, N1.

[0097] The principles disclosed above with respect to the implementation of the controller node and with respect to the flowchart of Fig. 4 apply here as well.

[0098] Embodiments relating to further details of interference mitigation in an IAB network 100, 200, 300a, 300b as performed by the first IAB node 1000 will now be disclosed with continued reference to Fig. 6.

[0099] In some examples, the first IAB node is an IAB donor node 110, 210 or some other IAB node. In some examples, the first IAB node is a parent IAB node 110, 210, 310 with respect to the middle IAB node 120, 220, 320. Hence, in some embodiments, the first IAB node is upstream the middle IAB node 120, 220, 320 and the third IAB node. The IAB node might then, as in Fig. 3, comprise a DU interface, where said first signal X1 or second signal X2 is transmitted, and said other of the first signal X1 and the second signal X2 is received, via the DU interface.

[0100] In some examples, the first IAB node is a user equipment 160b, 160c, 260b, 260c or an IAB node. In some examples, the first IAB node is a child IAB node 130, 230, 330 with respect to the middle IAB node 120, 220, 320. Hence, in some embodiments, the first IAB node is downstream the middle IAB node 120, 220, 320 and the third IAB node. The IAB node might then, as in Fig. 3, comprise an MT interface, where said first signal X1 or second signal X2 is transmitted, and said other of the first signal X1 and the second signal X2 is received, via the MT interface.

[0101] As disclosed above, in some aspects, the controller node 170, 270 configures the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330 for reception of the signals in the third time resource N3. Therefore, in some embodiments, the first IAB node is configured to perform (optional) step S302.

[0102] S302: The first IAB node receives reception configuration from the controller node 170, 270 for the IAB node to use when receiving said other of the first signal X1 and the second signal X2.

[0103] As disclosed above, in some non-limiting examples, the reception configuration pertains to at least one of: receive beam configuration, interference suppression scheme, indicating a limited set of restricted receive beams, etc..

[0104] As yet further disclosed above, the controller node 170, 270 might obtain capability reports about the different IAB nodes. The first IAB node might be configured to transmit such a capability report. Therefore, in some embodiments, the first IAB node is configured to perform (optional) step S304.

[0105] S304: The first IAB node sends a capability report to the controller node 170, 270.

[0106] As further disclosed above, in some non-limiting examples, the capability report comprises information pertaining to at least one of: capabilities for simultaneous transmission and / or simultaneous transmission, beamforming capabilities, power allocation capabilities, dynamic range capabilities, interference suppression capabilities, number, type, and constellations, of antennas. The third time resource N3 might then further be determined as a function of the information comprised in the capability report.

[0107] In some aspects, the controller node 170, 270 also schedules the parent IAB node 110, 210 and the child IAB node 130, 230, 330. Therefore, in some embodiments, the first IAB node is configured to perform (optional) step S306.

[0108] S306: The first IAB node receives scheduling from the controller node 170, 270 for the IAB node to, in the first time resource N1, N2, transmit said first signal X1 or second signal X2.

[0109] Further, the first IAB node might be configured to buffer the signal transmitted in step S308, i.e., either the first signal X1 transmitted in time resource N1 or the second signal X2 transmitted in second time resource N2 (depending on which signal was transmitted by the first IAB node in step S308). Hence, in some embodiments, the first IAB node is configured to perform (optional) step S310. S310: The first IAB node buffers said first signal X1 or second signal X2 after said first signal X1 or second signal X2 has been transmitted.

[0110] As disclosed above, there can be different ways for the third time resource N3 to be determined. Different embodiments relating thereto will now be described in turn.

[0111] As disclosed above, the middle IAB node 120, 220, 320 may receive the signals X1, X2 either using TDM or simultaneous reception from the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330.

[0112] Thus, in case of TDM, each of the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330 is allocated different time resources for transmission. That is, in some embodiments, the first time resource N1, N2 is different from the second time resource N2, N1. Then, as disclosed above, the third time resource N3 can be determined to have an offset with respect to the first time resource N1 and the second time resource N2 occurring latest in time, i.e., max{N1,N2}. That is, the third time resource N3 can be determined as max{N1,N2}+K, where N1 is the first time resource and N2 is the second time resource, and where K>0 is an integer (that is the aforementioned offset).

[0113] Further, in case of simultaneous reception, the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330 are both allocated the same time resources for transmission. That is, in some embodiments, the first time resource N1, N2 and the second time resource N2, N1 are both equal to a common time resource. Then, as disclosed above, the third time resource N3 can be determined to have an offset with respect to the common time resource N. That is, the third time resource N3 can be determined as N+K, where N is the common time resource, and where K>0 is an integer (that is the aforementioned offset).

[0114] Further aspects of operations performed by the first IAB node upon the reception in step S314 will be disclosed next.

[0115] For example, the first IAB node can be configured to remove, or at least mitigate or reduce, interference of the received signal using the buffered signal. In particular, the first IAB node is configured to perform (optional) step S316.

[0116] S316: The first IAB node performs interference suppression on said other of the first signal X1 and the second signal X2 by subtracting said first signal X1 or second signal X2 from said other of the first signal X1 and the second signal X2. In further detail, the decoding scheme used by the first IAB node when performing the interference suppression in step S316 may be based on successive interference cancellation or other interference rejection methods.

[0117] In this way, considering the case where the parent IAB node 110, 210, 310 sends the signal X1 in the first time resource N1, then the parent IAB node 110, 210, 310 can remove interference from the second signal X2 received in the third time resource N3 by using the signal X1 transmitted in time resource N1 (and buffered in step S310). This is because both the interfering signal X1 and the channel H1 (see, Fig. 3) is known to the parent IAB node 110, 210, 310, and thus the interference term X1*H1 can be removed in the time resource max{N1, N2}+K.

[0118] Alternatively, considering the case with simultaneous transmission of X1 and X2 by the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330, respectively, at time resource N, then the parent IAB node 110, 210, 310 can remove the interference of the signal received in time resource N+K by using the signal X1 transmitted in time resource N (and buffered in step S310). This is because both the interfering signal X1 and the channel H1 (see, Fig. 3) is known to the parent IAB node 110, 210, 310, and thus the interference term X1*H1 can be removed in the time resource N+K.

[0119] The same approach can be applied at the child IAB node 130, 230, 330.

[0120] In this way, considering the case where the child IAB node 130, 230, 330 sends the signal X2 in the second time resource N2, then the child IAB node 130, 230, 330 can remove interference from the first signal X1 received in the third time resource N3 by using the signal X2 transmitted in time resource N2 (and buffered in step S310). This is because both the interfering signal X2 and the channel H2 (see, Fig. 3) is known to the child IAB node 130, 230, 330, and thus the interference term X2*H2 can be removed in the time resource max{N1, N2}+K.

[0121] Alternatively, considering the case with simultaneous transmission of X1 and X2 by the parent IAB node 110, 210, 310 and the child IAB node 130, 230, 330, respectively, at time resource N, then the child IAB node 130, 230, 330 can remove the interference of the signal received in time resource N+K by using the signal X2 transmitted in time resource N (and buffered in step S310). This is because both the interfering signal X2 and the channel H2 (see, Fig. 3) is known to the child IAB node 130, 230, 330, and thus the interference term X2*H2 can be removed in the time resource N+K.

[0122] Then, upon having removed the interfering signal, the first IAB node can decode its intended signal interference-free. Consider next the communication setup of Fig. 7. In Fig. 7 is schematically illustrated an I AB network 700a, 700b, 700c comprising three I AB nodes 710, 720, 730. The I AB node 710 is a patent I AB node with respect to the middle IAB node 720, and the IAB node 730 is a child IAB node with respect to the middle IAB node 720. Here, the IAB node 710 may be an IAB donor or another IAB node whereas the IAB node 730 may be a UE or another IAB node.

[0123] The IAB network 700a is using TDM whereas the IAB network 700b is using simultaneous transmission. For the IAB network 700a, at a first time instant (t=N 1 ), an IAB node 720 is using its MT interface for receiving a first signal X1 from one IAB node 710. Then, at a second time instant (t=N2), the IAB node 720 is using its DU interface for receiving a second signal X2 from another IAB node 730. For the IAB network 700b, at a common time instant (t=N), the IAB node 720 is using its MT interface for receiving the first signal X1 from one IAB node 710 and its DU interface for receiving the second signal X2 from another IAB node 730.

[0124] In the IAB network 700c, the IAB node 720 transmits, in a third time resource (t=N3), the first signal X1 to the IAB node 730 and the second signal X2 to the IAB node 710. As illustrated in the IAB network 700c, one of the main challenges of simultaneous transmission is the additive interference from the MT interface of the IAB node 720 towards the IAB node 730 (over the channel H2) when the signal X2 is transmitted to the IAB node 710, and the additive interference from the DU interface of the IAB node 720 towards the IAB node 710 (over the channel H1) when the signal X1 is transmitted to the IAB node 730. Depending on the deployment, such an interference may affect the efficiency of the simultaneous operation significantly, if not handled correctly.

[0125] As disclosed above, while transmitting the signal X1 to the IAB node 730 causes interference to the IAB node 710, the IAB node 710 already knows the signal X1. Thus, if the IAB node 710 knows when the IAB node 720 transmits the signal X1 to the IAB node 730, i.e., the IAB node 710 knows U+K (where U is either max{N1, N2} or N, depending on which transmission scheme is used), IAB node 710 can remove the interference effect of the signal X1 from its received signal X2.

[0126] The same method can be applied in the IAB node 730; while transmitting the signal X2 to the IAB node 710 causes interference to the IAB node 730, the IAB node 730 already knows the signal X2. Thus, if the IAB node 730 knows when the IAB node 720 transmits the signal X2 to the IAB node 710, i.e., the IAB node 730 knows U+K (where U is either max{N1, N2} or N, depending on which transmission scheme is used), IAB node 730 can remove the interference effect of the signal X2 from its received signal X1. This requires I AB node 710 to have an estimate of the channel H1 and I AB node 730 to have an estimate of the channel H2. This can be easily achieved, especially since all the IAB nodes are assumed to be stationary. Here, for instance, the estimates of the channels can be based on measurements performed by the IAB nodes 710, 730 on reference signals as transmitted by the IAB node 720. For example, a first reference signal as sent from the MT interface of the IAB node 720 can be measured on by the IAB node 710, and a second reference signal as sent from the DU interface of the IAB node 720 can be measured on by the IAB node 730.

[0127] Proper coordination, scheduling, transmission, and reception of signals can then be performed in accordance with the above disclosed methods with respect to the flowcharts in Figs. 4, 5, and 6, thus enabling the IAB nodes 710, 730 to remove the interference.

[0128] Fig. 8 schematically illustrates, in terms of a number of structural units, the components of a controller node 800 according to an embodiment. Processing circuitry 810 is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a computer program product 1110a (as in Fig. 11), e.g. in the form of a storage medium 830. The processing circuitry 810 may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA).

[0129] Particularly, the processing circuitry 810 is configured to cause the controller node 800 to perform a set of operations, or steps, as disclosed above. For example, the storage medium 830 may store the set of operations, and the processing circuitry 810 may be configured to retrieve the set of operations from the storage medium 830 to cause the controller node 800 to perform the set of operations. The set of operations may be provided as a set of executable instructions. Thus the processing circuitry 810 is thereby arranged to execute methods as herein disclosed.

[0130] The storage medium 830 may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory.

[0131] The controller node 800 may further comprise a communications (comm.) interface 820 for communications with other entities, functions, nodes, and devices, such as the IAB nodes in the IAB networks. As such the communications interface 820 may comprise one or more transmitters and receivers, comprising analogue and digital components.

[0132] The processing circuitry 810 controls the general operation of the controller node 800 e.g. by sending data and control signals to the communications interface 820 and the storage medium 830, by receiving data and reports from the communications interface 820, and by retrieving data and instructions from the storage medium 830. Other components, as well as the related functionality, of the controller node 800 are omitted in order not to obscure the concepts presented herein.

[0133] Fig. 9 schematically illustrates, in terms of a number of structural units, the components of a middle IAB node 900 according to an embodiment. Processing circuitry 910 is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a computer program product 1110b (as in Fig. 11), e.g. in the form of a storage medium 930. The processing circuitry 910 may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA).

[0134] Particularly, the processing circuitry 910 is configured to cause the middle IAB node 900 to perform a set of operations, or steps, as disclosed above. For example, the storage medium 930 may store the set of operations, and the processing circuitry 910 may be configured to retrieve the set of operations from the storage medium 930 to cause the middle IAB node 900 to perform the set of operations. The set of operations may be provided as a set of executable instructions. Thus the processing circuitry 910 is thereby arranged to execute methods as herein disclosed.

[0135] The storage medium 930 may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory.

[0136] The middle IAB node 900 may further comprise a communications interface 920 for communications with other entities, functions, nodes, and devices, such as the controller node and other IAB nodes in the IAB networks. As such the communications interface 920 may comprise one or more transmitters and receivers, comprising analogue and digital components, possibly implementing an MT interface and / or a DU interface.

[0137] The processing circuitry 910 controls the general operation of the middle IAB node 900 e.g. by sending data and control signals to the communications interface 920 and the storage medium 930, by receiving data and reports from the communications interface 920, and by retrieving data and instructions from the storage medium 930. Other components, as well as the related functionality, of the middle IAB node 900 are omitted in order not to obscure the concepts presented herein.

[0138] Fig. 10 schematically illustrates, in terms of a number of structural units, the components of a first IAB node 1000 according to an embodiment. Processing circuitry 1010 is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a computer program product 1110c (as in Fig. 11), e.g. in the form of a storage medium 1030. The processing circuitry 1010 may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA).

[0139] Particularly, the processing circuitry 1010 is configured to cause the first IAB node 1000 to perform a set of operations, or steps, as disclosed above. For example, the storage medium 1030 may store the set of operations, and the processing circuitry 1010 may be configured to retrieve the set of operations from the storage medium 1030 to cause the first IAB node 1000 to perform the set of operations. The set of operations may be provided as a set of executable instructions. Thus the processing circuitry 1010 is thereby arranged to execute methods as herein disclosed. The storage medium 1030 may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory.

[0140] The first IAB node 1000 may further comprise a communications interface 1020 for communications with entities, functions, nodes, and devices, such as the controller node and other IAB nodes in the IAB networks. As such the communications interface 1020 may comprise one or more transmitters and receivers, comprising analogue and digital components, possibly implementing an MT interface and / or a DU interface. The processing circuitry 1010 controls the general operation of the first IAB node 1000 e.g. by sending data and control signals to the communications interface 1020 and the storage medium 1030, by receiving data and reports from the communications interface 1020, and by retrieving data and instructions from the storage medium 1030. Other components, as well as the related functionality, of the first IAB node 1000 are omitted in order not to obscure the concepts presented herein.

[0141] Fig. 11 shows one example of a computer program product 1110a, 1110b, 1110c comprising computer readable means 1130. On this computer readable means 1130, a computer program 1120a can be stored, which computer program 1120a can cause the processing circuitry 810 and thereto operatively coupled entities and devices, such as the communications interface 820 and the storage medium 830, to execute methods according to embodiments described herein. The computer program 1120a and / or computer program product 1110a may thus provide means for performing any steps of the controller node 170, 270, 800 as herein disclosed. On this computer readable means 1130, a computer program 1120b can be stored, which computer program 1120b can cause the processing circuitry 910 and thereto operatively coupled entities and devices, such as the communications interface 920 and the storage medium 930, to execute methods according to embodiments described herein. The computer program 1120b and / or computer program product 1110b may thus provide means for performing any steps of the middle IAB node 120, 220, 320, 720, 900 as herein disclosed. On this computer readable means 1130, a computer program 1120c can be stored, which computer program 1120c can cause the processing circuitry 1010 and thereto operatively coupled entities and devices, such as the communications interface 1020 and the storage medium 1030, to execute methods according to embodiments described herein. The computer program 1120c and / or computer program product 1110c may thus provide means for performing any steps of the first IAB node 1000 as herein disclosed. In the example of Fig. 11, the computer program product 1110a, 1110b, 1110c is illustrated as an optical disc, such as a CD (compact disc) or a DVD (digital versatile disc) or a Blu-Ray disc. The computer program product 1110a, 1110b, 1110c could also be embodied as a memory, such as a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), or an electrically erasable programmable read-only memory (EEPROM) and more particularly as a non-volatile storage medium of a device in an external memory such as a USB (Universal Serial Bus) memory or a Flash memory, such as a compact Flash memory. Thus, while the computer program 1120a, 1120b, 1120c is here schematically shown as a track on the depicted optical disk, the computer program 1120a, 1120b, 1120c can be stored in any way which is suitable for the computer program product 1110a, 1110b, 1110c.

[0142] The inventive concept has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended patent claims.

Claims

CLAIMS1 . A method for interference mitigation in an integrated access and backhaul, I AB, network (100, 200, 300a, 300b, 700a:700c), wherein the I AB network (100, 200, 300a, 300b, 700a:700c) comprises at least a parent IAB node (110, 210, 310, 710), a middle IAB node (120, 220, 320, 720) and a childI AB node (130, 230, 330, 730), wherein the method is performed by a controller node (170, 270) of the IAB network (100, 200, 300a, 300b, 700a:700c), and wherein the method comprises: scheduling (S108) transmission from the middle IAB node (120, 220, 320, 720) to the parent IAB node (110, 210, 310, 710) and the child IAB node (130, 230, 330, 730), wherein the middle IAB node (120, 220, 320, 720) is scheduled to, in a third time resource (N3) and upon reception of a first signal (X1) from the parent IAB node (110, 210, 310, 710) in a first time resource (N1) and reception of a second signal (X2) from the child IAB node (130, 230, 330, 730) in a second time resource (N2), simultaneously transmit the first signal (X1) to the child IAB node (130, 230, 330, 730) and the second signal (X2) to the parent IAB node (110, 210, 310, 710), and wherein the third time resource (N3) is determined as a function of the first time resource (N1) and the second time resource (N2); and providing (S110) information to the parent IAB node (110, 210, 310, 710) for the parent IAB node (110, 210, 310, 710) to, in the third time resource (N3), receive the second signal (X2) and the child IAB node (130, 230, 330, 730) to, in the third time resource (N3), receive the first signal (X1).

2. The method according to claim 1 , wherein, according to the function, the third time resource (N3) has an offset to the first time resource (N1) and the second time resource (N2).

3. The method according to claim 2, wherein the third time resource (N3) is determined by selecting the offset from a predetermined set of fixed values.

4. The method according to claim 1 , wherein the method further comprises: receiving (S104) a capability report from at least one of the middle IAB node (120, 220, 320, 720), the parent IAB node (110, 210, 310, 710), and the child IAB node (130, 230, 330, 730), wherein the capability report comprises information pertaining to at least one of the middle IAB node (120, 220, 320, 720), the parent IAB node (110, 210, 310, 710), and the child IAB node (130, 230, 330, 730) with respect to at least one of: capabilities for simultaneous transmission and / or simultaneous transmission, beamforming capabilities, power allocation capabilities, dynamic range capabilities, interference suppression capabilities, number, type, and constellations, of antennas.

5. The method according to claim 4, wherein the third time resource (N3) further is determined as a function of the information comprised in the capability report.

6. The method according to any preceding claim, wherein the third time resource (N3) further is determined as a function of at least one of: downlink and / or uplink data traffic in the I AB network (100, 200, 300a, 300b, 700a:700c), quality-of-service requirements in the IAB network (100, 200, 300a, 300b, 700a:700c), channel quality in the IAB network (100, 200, 300a, 300b, 700a:700c), decoding capabilities of the parent IAB node (110, 210, 310, 710) and the child IAB node (130, 230, 330, 730), buffering capabilities of the middle IAB node (120, 220, 320, 720).

7. The method according to any preceding claim, wherein the method further comprises: scheduling (S106) the parent IAB node (110, 210, 310, 710) to, in the first time resource (N1), transmit the first signal (X1), and the child IAB node (130, 230, 330, 730) to, in the second time resource (N2), transmit the second signal (X2).

8. The method according to any preceding claim, wherein the first time resource (N1) is different from the second time resource (N2).

9. The method according to claim 8, wherein, according to the function, the third time resource (N3) is determined as max{N1,N2}+K, where N1 is the first time resource and N2 is the second time resource, and where K>0 is an integer.

10. The method according to any of claims 1 to 7, wherein the first time resource (N1) and the second time resource (N2) are both equal to a common time resource.11 . The method according to claim 10, wherein, according to the function, the third time resource (N3) is determined as N+K, where N is the common time resource, and where K>0 is an integer.

12. The method according to claim 2 in combination with either claim 9 or claim 11 , wherein the offset is equal to K.

13. The method according to any preceding claim, wherein the method further comprises: providing (S102) transmission configuration to the middle IAB node (120, 220, 320, 720) for use when transmitting the first signal (X1) and the second signal (X2), and reception configuration to the parent IAB node (110, 210, 310, 710) for use when receiving the second signal (X2) and to the child IAB node (130, 230, 330, 730) for use when receiving the first signal (X1).

14. The method according to claim 13, wherein the transmission configuration pertains to at least one of enabling simultaneous transmission, transmit beam configuration, transmission power, frequency bandwidth, modulation and coding scheme.

15. The method according to claim 13, wherein the reception configuration pertains to at least one of: receive beam configuration, interference suppression scheme.

16. The method according to any preceding claim, wherein the controller node (170, 270) is collocated with, integrated with, or part of, one of: the parent I AB node (110, 210, 310, 710), the middle IAB node (120, 220, 320, 720), a donor IAB node (110, 210) in the I AB network (100, 200, 300a, 300b, 700a:700c), a core network node.

17. A method for interference mitigation in an integrated access and backhaul, IAB, network (100, 200, 300a, 300b, 700a:700c), wherein the IAB network (100, 200, 300a, 300b, 700a:700c) comprises at least a parent IAB node (110, 210, 310, 710), a middle IAB node (120, 220, 320, 720) and a child IAB node (130, 230, 330, 730), wherein the method is performed by the middle IAB node (120, 220, 320, 720), and wherein the method comprises: receiving (S206), in a first time resource (N 1 ), a first signal (X1) from the parent IAB node (110, 210, 310, 710) and, in a second time resource (N2), a second signal (X2) from the child IAB node (130, 230, 330, 730); receiving (S208), from a controller node (170, 270) of the IAB network (100, 200, 300a, 300b, 700a:700c), scheduling of transmission from the middle IAB node (120, 220, 320, 720) to the parent IAB node (110, 210, 310, 710) and the child IAB node (130, 230, 330, 730), wherein, according to the scheduling, the middle IAB node (120, 220, 320, 720) is scheduled to, in a third time resource (N3), simultaneously transmit the first signal (X1) to the child IAB node (130, 230, 330, 730) and the second signal (X2) to the parent IAB node (110, 210, 310, 710), wherein the third time resource (N3) is determined as a function of the first time resource (N1) and the second time resource (N2); and transmitting (S210), in the third time resource (N3), the first signal (X1) to the child IAB node (130, 230, 330, 730) and the second signal (X2) to the parent IAB node (110, 210, 310, 710).

18. The method according to claim 17, wherein the method further comprises: sending (S204) a capability report to the controller node (170, 270), wherein the capability report comprises information pertaining to at least one of: capabilities for simultaneous transmissionand / or simultaneous transmission, beamforming capabilities, power allocation capabilities, dynamic range capabilities, interference suppression capabilities, number, type, and constellations, of antennas.

19. The method according to claim 18, wherein the third time resource (N3) further is determined as a function of the information comprised in the capability report.

20. The method according to any of claims 17 to 19, wherein the first time resource (N1) is different from the second time resource (N2).21 . The method according to claim 20, wherein, according to the function, the third time resource (N3) is determined as max{N1,N2}+K, where N1 is the first time resource and N2 is the second time resource, and where K>0 is an integer.

22. The method according to any of claims 17 to 19, wherein the first time resource (N1) and the second time resource (N2) are both equal to a common time resource.

23. The method according to claim 22, wherein, according to the function, the third time resource (N3) is determined as N+K, where N is the common time resource, and where K>0 is an integer.

24. The method according to any of claims 17 to 23, wherein the method further comprises: receiving (S202) transmission configuration from the controller node (170, 270) for the middle IAB node (120, 220, 320, 720) to use when transmitting the first signal (X1) and the second signal (X2).

25. The method according to claim 24, wherein the transmission configuration pertains to at least one of enabling simultaneous transmission, transmit beam configuration, transmission power, frequency bandwidth, modulation and coding scheme.

26. The method according to any of claims 17 to 25, wherein the middle IAB node (120, 220, 320, 720) comprises a mobile termination, MT interface, and a distributed unit, DU, interface, wherein the first signal (X1) is received via the MT interface, the second signal (X2) is received via the DU interface, the first signal (X1) is transmitted via the DU interface, and the second signal (X2) is transmitted via the MT interface.

27. The method according to any of claims 17 to 26, wherein the middle IAB node (120, 220, 320, 720) is downstream the parent IAB node (110, 210, 310, 710) and upstream the child IAB node (130, 230, 330, 730).

28. A method for interference mitigation in an integrated access and backhaul, IAB, network (100, 200, 300a, 300b, 700a:700c), wherein the IAB network (100, 200, 300a, 300b, 700a:700c) comprises at least a first IAB node, a middle IAB node (120, 220, 320, 720) and a third IAB node, wherein the method is performed by the first IAB node, and wherein the method comprises: transmitting (S308), in a first time resource (N1, N2), either a first signal (X1) or a second signal (X2) towards the third IAB node via the middle IAB node (120, 220, 320, 720); receiving (S312) information from the controller node (170, 270) for the IAB node to, in the third time resource (N3), receive another of the first signal (X1) and the second signal (X2); and receiving (S314), in a third time resource (N3), said another of the first signal (X1) and the second signal (X2) from the third IAB node via the middle IAB node (120, 220, 320, 720), wherein said another of the first signal (X1) and the second signal (X2) is transmitted from the third IAB node in a second time resource (N2, N 1 ), and wherein the third time resource (N3) is determined as a function of the first time resource (N1 , N2) and the second time resource (N2, N1).

29. The method according to claim 28, wherein the method further comprises: sending (S304) a capability report to the controller node (170, 270), wherein the capability report comprises information pertaining to at least one of: capabilities for simultaneous transmission and / or simultaneous transmission, beamforming capabilities, power allocation capabilities, dynamic range capabilities, interference suppression capabilities, number, type, and constellations, of antennas.

30. The method according to claim 29, wherein the third time resource (N3) further is determined as a function of the information comprised in the capability report.31 . The method according to any of claims 28 to 30, wherein the method further comprises: receiving (S306) scheduling from the controller node (170, 270) for the IAB node to, in the first time resource (N1 , N2), transmit said first signal (X1) or second signal (X2).

32. The method according to any of claims 28 to 31, wherein the first time resource (N1, N2) is different from the second time resource (N2, N 1 ).

33. The method according to any of claims 28 to 31, wherein the first time resource (N1, N2) and the second time resource (N2, N1) are both equal to a common time resource.

34. The method according to any of claims 28 to 33, wherein the method further comprises:receiving (S302) reception configuration from the controller node (170, 270) for the I AB node to use when receiving said another of the first signal (X1) and the second signal (X2).

35. The method according to claim 34, wherein the reception configuration pertains to at least one of: receive beam configuration, interference suppression scheme.

36. The method according to any of claims 28 to 35, wherein the method further comprises: buffering (S310) said first signal (X1) or second signal (X2) after said first signal (X1) or second signal (X2) has been transmitted.

37. The method according to claim 36, wherein the method further comprises: performing (S316) interference suppression on said another of the first signal (X1) and the second signal (X2) by subtracting said first signal (X1) or second signal (X2) from said another of the first signal (X1) and the second signal (X2).

38. The method according to any of claims 28 to 37, wherein the first IAB node is upstream the middle IAB node (120, 220, 320, 720) and the third IAB node.

39. The method according to claim 38, wherein the IAB node comprises a distributed unit, DU, interface, and wherein said first signal (X1) or second signal (X2) is transmitted, and said another of the first signal (X1) and the second signal (X2) is received, via the DU interface.

40. The method according to claim 38 or 39, wherein the first IAB node is an IAB donor node (110, 210).41 . The method according to any of claims 28 to 40, wherein the first IAB node is downstream the middle IAB node (120, 220, 320, 720) and the third IAB node.

42. The method according to claim 41 , wherein the IAB node comprises a mobile termination, MT interface, and wherein said first signal (X1) or second signal (X2) is transmitted, and said another of the first signal (X1) and the second signal (X2) is received, via the MT interface.

43. The method according to claim 41 or 42, wherein the first IAB node is a user equipment (160b, 160c, 260b, 260c).

44. A controller node (170, 270, 800) for interference mitigation in an integrated access and backhaul, IAB, network (100, 200, 300a, 300b, 700a:700c), wherein the IAB network (100, 200, 300a, 300b, 700a:700c) comprises at least a parent IAB node (110, 210, 310, 710), a middle IAB node (120,220, 320, 720) and a child I AB node (130, 230, 330, 730), the controller node (170, 270, 800) comprising processing circuitry (810), the processing circuitry being configured to cause the controller node (170, 270, 800) to: schedule transmission from the middle I AB node (120, 220, 320, 720) to the parent I AB node (110, 210, 310, 710) and the child I AB node (130, 230, 330, 730), wherein the middle IAB node (120, 220, 320, 720) is scheduled to, in a third time resource (N3) and upon reception of a first signal (X1) from the parent IAB node (110, 210, 310, 710) in a first time resource (N1) and reception of a second signal (X2) from the child IAB node (130, 230, 330, 730) in a second time resource (N2), simultaneously transmit the first signal (X1) to the child IAB node (130, 230, 330, 730) and the second signal (X2) to the parent IAB node (110, 210, 310, 710), and wherein the third time resource (N3) is determined as a function of the first time resource (N1) and the second time resource (N2); and provide information to the parent IAB node (110, 210, 310, 710) for the parent IAB node (110, 210, 310, 710) to, in the third time resource (N3), receive the second signal (X2) and the child IAB node (130, 230, 330, 730) to, in the third time resource (N3), receive the first signal (X1).

45. A middle integrated access and backhaul, IAB, node (120, 220, 320, 720, 900) for interference mitigation in an IAB network (100, 200, 300a, 300b, 700a:700c), wherein the IAB network (100, 200, 300a, 300b, 700a:700c) comprises at least a parent IAB node (110, 210, 310, 710), the middle IAB node (120, 220, 320, 720) and a child IAB node (130, 230, 330, 730), the middle IAB node (120, 220, 320, 720, 900) comprising processing circuitry (910), the processing circuitry being configured to cause the middle IAB node (120, 220, 320, 720, 900) to: receive, in a first time resource (N 1 ), a first signal (X1) from the parent IAB node (110, 210, 310, 710) and, in a second time resource (N2), a second signal (X2) from the child IAB node (130, 230, 330, 730); receive, from a controller node (170, 270) of the IAB network (100, 200, 300a, 300b, 700a:700c), scheduling of transmission from the middle IAB node (120, 220, 320, 720) to the parent IAB node (110, 210, 310, 710) and the child IAB node (130, 230, 330, 730), wherein, according to the scheduling, the middle IAB node (120, 220, 320, 720) is scheduled to, in a third time resource (N3), simultaneously transmit the first signal (X1) to the child IAB node (130, 230, 330, 730) and the second signal (X2) to the parent IAB node (110, 210, 310, 710), wherein the third time resource (N3) is determined as a function of the first time resource (N1) and the second time resource (N2); andtransmit, in the third time resource (N3), the first signal (X1) to the child I AB node (130, 230, 330, 730) and the second signal (X2) to the parent I AB node (110, 210, 310, 710).

46. A first integrated access and backhaul, IAB, node (1000) for interference mitigation in an I AB network (100, 200, 300a, 300b, 700a:700c), wherein the IAB network (100, 200, 300a, 300b, 700a:700c) comprises at least the first IAB node, a middle IAB node (120, 220, 320, 720) and a third IAB node, the first IAB node (1000) comprising processing circuitry (1010), the processing circuitry being configured to cause the first IAB node (1000) to: transmit, in a first time resource (N1, N2), either a first signal (X1) or a second signal (X2) towards the third IAB node via the middle IAB node (120, 220, 320, 720); receive information from the controller node (170, 270) for the IAB node to, in the third time resource (N3), receive another of the first signal (X1) and the second signal (X2); and receive, in a third time resource (N3), said another of the first signal (X1) and the second signal (X2) from the third IAB node via the middle IAB node (120, 220, 320, 720), wherein said another of the first signal (X1) and the second signal (X2) is transmitted from the third IAB node in a second time resource (N2, N 1 ), and wherein the third time resource (N3) is determined as a function of the first time resource (N1, N2) and the second time resource (N2, N1).

47. A computer program (1120a) for interference mitigation in an integrated access and backhaul, IAB, network (100, 200, 300a, 300b, 700a:700c), wherein the IAB network (100, 200, 300a, 300b, 700a:700c) comprises at least a parent IAB node (110, 210, 310, 710), a middle IAB node (120, 220, 320, 720) and a child IAB node (130, 230, 330, 730), the computer program comprising computer code which, when run on processing circuitry (810) of a controller node (170, 270, 800) of the IAB network (100, 200, 300a, 300b, 700a:700c), causes the controller node (170, 270, 800) to: schedule (S108) transmission from the middle IAB node (120, 220, 320, 720) to the parent IAB node (110, 210, 310, 710) and the child IAB node (130, 230, 330, 730), wherein the middle IAB node (120, 220, 320, 720) is scheduled to, in a third time resource (N3) and upon reception of a first signal (X1) from the parent IAB node (110, 210, 310, 710) in a first time resource (N1) and reception of a second signal (X2) from the child IAB node (130, 230, 330, 730) in a second time resource (N2), simultaneously transmit the first signal (X1) to the child IAB node (130, 230, 330, 730) and the second signal (X2) to the parent IAB node (110, 210, 310, 710), andwherein the third time resource (N3) is determined as a function of the first time resource (N1) and the second time resource (N2); and provide (S110) information to the parent IAB node (110, 210, 310, 710) for the parent I AB node (110, 210, 310, 710) to, in the third time resource (N3), receive the second signal (X2) and the child IAB node (130, 230, 330, 730) to, in the third time resource (N3), receive the first signal (X1).

48. A computer program (1120b) for interference mitigation in an integrated access and backhaul, IAB, network (100, 200, 300a, 300b, 700a:700c), wherein the IAB network (100, 200, 300a, 300b, 700a:700c) comprises at least a parent IAB node (110, 210, 310, 710), a middle IAB node (120, 220, 320, 720) and a child IAB node (130, 230, 330, 730), the computer program comprising computer code which, when run on processing circuitry (910) of the middle IAB node (120, 220, 320, 720, 900), causes the middle IAB node (120, 220, 320, 720, 900) to: receive (S206), in a first time resource (N 1 ), a first signal (X1) from the parent IAB node (110, 210, 310, 710) and, in a second time resource (N2), a second signal (X2) from the child IAB node (130, 230, 330, 730); receive (S208), from a controller node (170, 270) of the IAB network (100, 200, 300a, 300b, 700a:700c), scheduling of transmission from the middle IAB node (120, 220, 320, 720) to the parent IAB node (110, 210, 310, 710) and the child IAB node (130, 230, 330, 730), wherein, according to the scheduling, the middle IAB node (120, 220, 320, 720) is scheduled to, in a third time resource (N3), simultaneously transmit the first signal (X1) to the child IAB node (130, 230, 330, 730) and the second signal (X2) to the parent IAB node (110, 210, 310, 710), wherein the third time resource (N3) is determined as a function of the first time resource (N1) and the second time resource (N2); and transmit (S210), in the third time resource (N3), the first signal (X1) to the child IAB node (130, 230, 330, 730) and the second signal (X2) to the parent IAB node (110, 210, 310, 710).

49. A computer program (1120c) for interference mitigation in an integrated access and backhaul, IAB, network (100, 200, 300a, 300b, 700a:700c), wherein the IAB network (100, 200, 300a, 300b, 700a:700c) comprises at least a first IAB node, a middle IAB node (120, 220, 320, 720) and a third IAB node, the computer program comprising computer code which, when run on processing circuitry (1010) of the first IAB node (1000), causes the first IAB node (1000) to: transmit (S308), in a first time resource (N1, N2), either a first signal (X1) or a second signal (X2) towards the third IAB node via the middle IAB node (120, 220, 320, 720);receive (S312) information from the controller node (170, 270) for the I AB node to, in the third time resource (N3), receive another of the first signal (X1) and the second signal (X2); and receive (S314), in a third time resource (N3), said another of the first signal (X1) and the second signal (X2) from the third I AB node via the middle I AB node (120, 220, 320, 720), wherein said another of the first signal (X1) and the second signal (X2) is transmitted from the third IAB node in a second time resource (N2, N 1 ), and wherein the third time resource (N3) is determined as a function of the first time resource (N1 , N2) and the second time resource (N2, N1).

50. A computer program product (5110a, 1110b, 1110c) comprising a computer program (1120a, 1120b, 1120c) according to at least one of claims 47, 48 and 49, and a computer readable storage medium (1130) on which the computer program is stored.

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