WO2021043385A1

WO2021043385A1 - Network coordination and interference handling in telecommunication systems

Info

Publication number: WO2021043385A1
Application number: PCT/EP2019/073400
Authority: WO
Inventors: Klaus Ingemann Pedersen; Gilberto BERARDINELLI; Fuad ABINADER
Original assignee: Nokia Technologies Oy
Priority date: 2019-09-03
Filing date: 2019-09-03
Publication date: 2021-03-11

Abstract

There is provided a method, comprising receiving, by a second network node from a first network node, a message comprising time-frequency resource allocation characteristics for one or more user equipments served by the first network node, wherein the one or more user equipments served by the first network node is subject to interference at least from the second network node;and/or transmitting, by the second network node to the first network node, a message comprising time-frequency resource allocation characteristics for one or more user equipments served by the second network node, wherein the one or more user equipments served by the second network node is subject to interference at least from the first network node; and reducing inter-cell interference based on the message.

Description

Network Coordination and Interference Handling in Telecommunication Systems

FIELD

[0001] Various embodiments relate to network coordination and interference handling.

BACKGROUND

[0002] The industrial internet of things (IIoT) is a network of intelligent devices connected to form systems that e.g. monitor, collect, exchange and analyse data. Large amount of data needs to be transferred between the devices of an IoT installation. Traffic between the devices has strict latency and/or jitter requirements. IIoT transmissions are sensitive to interference which may cause reception errors for subsequent retransmissions resulting in violation of latency and/or jitter requirements.

[0003] Thus, there is a need for improved interference handling.

SUMMARY

[0004] According to some aspects, there is provided the subject-matter of the independent claims. Some example embodiments are defined in the dependent claims. The scope of protection sought for various example embodiments is set out by the independent claims. The embodiments, examples and features, if any, described in this specification that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various example embodiments.

[0005] According to a first aspect of the present disclosure, there is provided an apparatus which is a second network node comprising means for receiving, from a first network node, a message comprising time-frequency resource allocation characteristics for one or more user equipments served by the first network node, wherein the one or more user equipments served by the first network node is subject to interference at least from the second network node; and/or transmitting, to the first network node, a message comprising time- frequency resource allocation characteristics for one or more user equipments served by the second network node, wherein the one or more user equipments served by the second network node is subject to interference at least from the first network node; and reducing inter-cell interference based on the message.

[0006] According to a second aspect of the present disclosure, there is provided an apparatus which is a first network node comprising means for transmitting, to a second network node, a message comprising time- frequency resource allocation characteristics for one or more user equipments served by the first network node, wherein the one or more user equipments served by the first network node is subject to interference at least from the second network node; and/or receiving, from the second network node, a message comprising time- frequency resource allocation characteristics for one or more user equipments served by the second network node, wherein the one or more user equipments served by the second network node is subject to interference at least from the first network node; and reducing inter-cell interference based on the message.

[0007] According to a third aspect of the present disclosure, there is provided an apparatus of any preceding claim, comprising a central unit and one or more distributed unit, the central unit comprising means for configuring a second user equipment served by the distributed unit with a desired time-periodicity of resource allocations; transmitting, to the distributed unit, a message comprising time -periodicity of the resource allocation; receiving, from the distributed unit, a message comprising a number of required physical resource blocks that it will allocate to the second user equipment; and transmitting, to the distributed unit, a message comprising instruction for the distributed unit to use certain physical resource blocks. [0008] According to a fourth aspect of the present disclosure, there is provided a method, comprising receiving, by a second network node from a first network node, a message comprising time- frequency resource allocation characteristics for one or more user equipments served by the first network node, wherein the one or more user equipments served by the first network node is subject to interference at least from the second network node; and/or transmitting, by the second network node to the first network node, a message comprising time- frequency resource allocation characteristics for one or more user equipments served by the second network node, wherein the one or more user equipments served by the second network node is subject to interference at least from the first network node; and reducing inter-cell interference based on the message.

[0009] According to a fifth aspect of the present disclosure, there is provided a method, comprising transmitting, by a first network node to a second network node, a message comprising time- frequency resource allocation characteristics for one or more user equipments served by the first network node, wherein the one or more user equipments served by the first network node is subject to interference at least from the second network node; and/or receiving, from the second network node, a message comprising time- frequency resource allocation characteristics for one or more user equipments served by the second network node, wherein the one or more user equipments served by the second network node is subject to interference at least from the first network node; and reducing inter-cell interference based on the message.

[0010] According to a sixth aspect of the present disclosure, there is provided a method, comprising receiving, by a victim user equipment served by a first network node and subject to interference at least from a second network node, a message from the first network node comprising interference characteristics of the interference from the second network node; and performing interference cancellation and/or interference mitigation based on the received interference characteristics.

[0011] According to still further aspects, there may be provided a computer readable medium, optionally non-transitory, having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least perform the method of fourth, fifth, and/or sixth aspects.

[0012] According to still further aspects, there may be provided a computer program configured to cause the method of fourth, fifth, and/or sixth aspects to be performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Fig. 1 shows, by way of an example, a deterministic time- frequency domain resource allocation pattern for one user equipment;

[0014] Fig. 2 shows, by way of an example, a network architecture;

[0015] Fig. 3 shows, by way of an example, a block diagram of an apparatus 300;

[0016] Fig. 4a is a flow graph of a method for reducing inter-cell interference;

[0017] Fig. 4b is a flow graph of a method for reducing inter-cell interference;

[0018] Fig. 5 shows, by way of an example, a signalling flow diagram;

[0019] Fig. 6 shows, by way of an example, a signalling flow diagram;

[0020] Fig. 7 shows, by way of an example, a signalling flow diagram;

[0021] Fig. 8 shows, by way of an example, a signalling flow diagram;

[0022] Fig. 9a shows, by way of an example, a signalling flow diagram;

[0023] Fig. 9b shows, by way of an example, a flow graph of a method for reducing inter-cell interference; and

[0024] Fig. 10 shows, by way of an example, a signalling flow diagram.

DETAILED DESCRIPTION

[0025] The industrial internet of things (IIoT) refers to interconnected devices, e.g. sensors and instruments, which are networked together with computers’ industrial applications, e.g. manufacturing and energy management. IIoT is a network of intelligent devices connected to form systems that e.g. monitor, collect, exchange and analyse data. IIoT systems may be considered as a layered modular architecture of digital technology. The device layer refers to the physical components, such as sensors which collect the data, and actuators, which act based on received commands. The network layer comprises physical network buses, cloud computing and communication protocols that aggregate and transport the collected data to the service layer. The service layer comprises applications that manipulate and combine data into information that may be e.g. displayed on the driver dashboard. The top-most layer is the content layer or the user interface, e.g. screens, tablets and/or smart glasses.

[0026] The dominant traffic type for IIoT, or Factories of the Future (FoF), is deterministic with fixed periodicity, fixed payload size, and strict latency and jitter requirements. This applies also for Time- Sensitive Communications (TSC), also known as Time- Sensitive Networking (TSN). Downlink traffic is therefore typically scheduled with semi persistent scheduling (SPS). The scheduling may be referred to as radio resource allocation. Scheduling with SPS means that users are scheduled on the same frequency domain resources with a fixed time-domain periodicity. For the uplink traffic, configured grant (CG) resource allocation patterns may be used. The CG means that the network, e.g. a 5G network, enables multiple devices to share the periodic resources.

[0027] The new radio (NR) solution for the SPS, which is used for downlink allocations, may be summarized as follows. The time-domain periodicity may be configured by Radio Resource Control (RRC) signalling. The corresponding frequency- domain allocation and starting time may be given with the Downlink Control Information (DCI) activation which may be scrambled with the Configured Scheduling - Radio Network Temporary Identifier (CS-RNTI). Fixed modulation and coding scheme (MCS) may be assumed for the allocations until a new DCI is given.

[0028] The NR solution for the CG, which is used for uplink allocations, may be summarized as follows. In the CG Type 1, the uplink grant is provided by RRC, i.e. all is configured by RRC, such as time- frequency allocation grid, MCS, etc. In the CG Type 2, the uplink grant is provided roughly similarly as in the SPS.

[0029] Fig. 1 shows, by way of an example, a deterministic time- frequency domain resource allocation pattern 100 for one single user equipment (UE). In this example, the vertical axis 110 is time and the horizontal axis 120 refers to frequency domain resources.

[0030] Fig. 2 shows, by way of an example, a network architecture, e.g. 5G NR architecture 200. The next generation radio access network (NG-RAN) 205 comprises a set of network nodes 210, 212, 214, 216, 218, e.g. gNBs, connected to the 5G core network (5GC) 220 through the NG interface 230, 232. The gNBs, i.e. next generation nodeBs, may be interconnected through the Xn interface, e.g. Xn control plane interface Xn-C 240. A gNB may comprise a gNB central unit 218 (gNB-CU) and one or more gNB distributed unit(s) 214, 216 (gNB-DU). A gNB-CE and a gNB-DU are connected via FI interfaces 250, 252. FI interface 250, 252 provides means for interconnecting a gNB-CU and a gNB- DU of a gNB within an NG-RAN. FI interface may e.g. separate the Radio Network Fayer and Transport Network Fayer and/or enable exchange of UE associated information and non-UE associated information. The 5G NR architecture also allows Cloud-RAN or Centralized-RAN implementation with one or more CU, each serving a large number of DUs. The network vendor or operator may decide on which of the available architecture options to implement and deploy. For example, in locations or areas with availability of fiber connections, one CU may be set to serve large number of DUs with FI latencies of e.g. 50-10 micro seconds.

[0031] The CU may comprise entities such as RRC, Service Data Adaptation Protocol (SDAP), and Packet Data Convergence Protocol (PDCP). The DU may comprise entities such as Radio Fink Control (RFC), Medium Access Control (MAC) and PHY (physical) protocol layers.

[0032] IIoT and/or TSC transmissions may be sensitive to inter-cell interference which may be caused by a dense network of base stations or access points. Interference may be the dominant cause of e.g. reception errors. The reception errors may trigger a retransmission that may result in violation of latency and/or jitter requirements.

[0033] The flexibility offered by the physical layer design of 5G NR may enable new inter-cell interference coordination (ICIC) mechanisms to support new services, e.g. TSN and those that rely on ultra-reliable low latency communications (URFFC).

[0034] To address the multi-cell or multi-user resource allocation and inter-cell interference problem, e.g. with deterministic IIoT and/or TSC type of traffic, methods are provided to coordinate time-frequency resource allocation patterns for deterministic traffic to reduce or minimize the inter-cell interference coupling for distributed and centralized NR network architectures. These kinds of methods may be especially needed for highly time-critical and jitter-sensitive time sensitive communication (TSC) type of traffic.

[0035] An example apparatus capable of performing the method is described first, and then the method will be described referring also to the figures showing examples how the methods may be applied. [0036] Fig. 3 shows, by way of an example, a block diagram of an apparatus 300. Illustrated is an apparatus or device 300, which may comprise, for example, a network node, or a mobile communication device such as a user device or user equipment UE. Comprised in device 300 is processor 310, which may comprise, for example, a single- or multi-core processor wherein a single-core processor comprises one processing core and a multi-core processor comprises more than one processing core. Processor 310 may comprise, in general, a control device. Processor 310 may comprise more than one processor. Processor 310 may be a control device. A processing core may comprise, for example, a Cortex- A8 processing core manufactured by ARM Holdings or a Steamroller processing core designed by Advanced Micro Devices Corporation. Processor 310 may comprise at least one Qualcomm Snapdragon and/or Intel Atom processor. Processor 310 may comprise at least one application-specific integrated circuit, ASIC. Processor 310 may comprise at least one field-programmable gate array, FPGA. Processor 310 may be means for performing method steps in device 300. Processor 310 may be configured, at least in part by computer instructions, to perform actions, e.g. the method(s) as disclosed herein.

[0037] A processor may comprise circuitry, or be constituted as circuitry or circuitries, the circuitry or circuitries being configured to perform phases of methods in accordance with embodiments described herein. As used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations, such as implementations in only analog and/or digital circuitry, and (b) combinations of hardware circuits and software, such as, as applicable: (i) a combination of analog and/or digital hardware circuit(s) with software/firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0038] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0039] Device 300 may comprise memory 320. Memory 320 may comprise random- access memory and/or permanent memory. Memory 320 may comprise at least one RAM chip. Memory 320 may comprise solid-state, magnetic, optical and/or holographic memory, for example. Memory 320 may be at least in part accessible to processor 310. Memory 320 may be at least in part comprised in processor 310. Memory 320 may be means for storing information. Memory 320 may comprise computer instructions that processor 310 is configured to execute. When computer instructions configured to cause processor 310 to perform certain actions are stored in memory 320, and device 300 overall is configured to run under the direction of processor 310 using computer instructions from memory 320, processor 310 and/or its at least one processing core may be considered to be configured to perform said certain actions. Memory 320 may be at least in part comprised in processor 310. Memory 320 may be at least in part external to device 300 but accessible to device 300.

[0040] Device 300 may comprise a transmitter 330. Device 300 may comprise a receiver 340. Transmitter 330 and receiver 340 may be configured to transmit and receive, respectively, information in accordance with at least one cellular or non-cellular standard. Transmitter 330 may comprise more than one transmiter. Receiver 340 may comprise more than one receiver. Transmiter 330 and/or receiver 340 may be configured to operate in accordance with a mobile communication system standards, such as 5G, long term evolution, LTE, wireless local area network, WLAN and/or Ethernet.

[0041] Device 300 may comprise a near-field communication, NFC, transceiver 350. NFC transceiver 350 may support at least one NFC technology, such as NFC, Bluetooth, Wibree or similar technologies.

[0042] Device 300 may comprise user interface, UI, 360. UI 360 may comprise at least one of a display, a keyboard, a touchscreen, a vibrator arranged to signal to a user by causing device 300 to vibrate, a speaker and a microphone. A user may be able to operate device 300 via UI 360, for example to accept incoming telephone calls, to originate telephone calls or video calls, to browse the Internet, to manage digital files stored in memory 320 or on a cloud accessible via transmitter 330 and receiver 340, or via NFC transceiver 350, and/or to play games.

[0043] Device 300 may comprise or be arranged to accept a user identity module 370. User identity module 370 may comprise, for example, a subscriber identity module, SIM, card installable in device 300. A user identity module 370 may comprise information identifying a subscription of a user of device 300. A user identity module 370 may comprise cryptographic information usable to verify the identity of a user of device 300 and/or to facilitate encryption of communicated information and billing of the user of device 300 for communication effected via device 300.

[0044] Processor 310 may be furnished with a transmitter arranged to output information from processor 310, via electrical leads internal to device 300, to other devices comprised in device 300. Such a transmitter may comprise a serial bus transmitter arranged to, for example, output information via at least one electrical lead to memory 320 for storage therein. Alternatively to a serial bus, the transmitter may comprise a parallel bus transmitter. Likewise processor 310 may comprise a receiver arranged to receive information in processor 310, via electrical leads internal to device 300, from other devices comprised in device 300. Such a receiver may comprise a serial bus receiver arranged to, for example, receive information via at least one electrical lead from receiver 340 for processing in processor 310. Alternatively to a serial bus, the receiver may comprise a parallel bus receiver.

[0045] Device 300 may comprise further devices not illustrated in Fig. 3. For example, where device 300 comprises a smartphone, it may comprise at least one digital camera. Some devices 300 may comprise a back-facing camera and a front-facing camera, wherein the back-facing camera may be intended for digital photography and the front facing camera for video telephony. Device 300 may comprise a fingerprint sensor arranged to authenticate, at least in part, a user of device 300. In some embodiments, device 300 lacks at least one device described above. For example, some devices 300 may lack a NFC transceiver 350 and/or user identity module 370.

[0046] Processor 310, memory 320, transmitter 330, receiver 340, NFC transceiver 350, UI 360 and/or user identity module 370 may be interconnected by electrical leads internal to device 300 in a multitude of different ways. For example, each of the aforementioned devices may be separately connected to a master bus internal to device 300, to allow for the devices to exchange information. However, as the skilled person will appreciate, this is only one example and depending on the embodiment various ways of interconnecting at least two of the aforementioned devices may be selected.

[0047] Fig. 4a is a flow graph of a method 400 for reducing inter-cell interference. The phases of the illustrated method may be performed in a network node, e.g. a second network node, e.g. gNB#2, or in a control device configured to control the functioning thereof, when installed therein. The method 400 comprises receiving 410, by a second network node from a first network node, a message comprising time- frequency resource allocation characteristics for one or more user equipments served by the first network node, wherein the one or more user equipments served by the first network node is subject to interference at least from the second network node; and/or transmitting 420, by the second network node to the first network node, a message comprising time- frequency resource allocation characteristics for one or more user equipments served by the second network node, wherein the one or more user equipments served by the second network node is subject to interference at least from the first network node. The method 400 comprises reducing 430 inter-cell interference based on the message.

[0048] Reducing the interference may comprise various actions. These actions may comprise e.g. adjustments for the UE, or re-allocation of the UE to use a different radio resource allocation pattern. Adjustments for the UE may comprise e.g. reducing the user equipment’s transmission power, and/or adjusting the multiple input multiple output transmission configuration of the user equipment. More possible ways to reduce the interference will be explained below along with example signalling flowcharts.

[0049] Fig. 4b is a flow graph of a method 450 for reducing inter-cell interference. The phases of the illustrated method may be performed in a network node, e.g. a first network node, e.g. gNB#l, or in a control device configured to control the functioning thereof, when installed therein. The method 450 comprises transmitting 460, by a first network node to a second network node, a message comprising time- frequency resource allocation characteristics for one or more user equipments served by the first network node, wherein the one or more user equipments served by the first network node is subject to interference at least from the second network node; and/or receiving 470, from the second network node, a message comprising time-frequency resource allocation characteristics for one or more user equipments served by the second network node, wherein the one or more user equipments served by the second network node is subject to interference at least from the first network node. The method 450 comprises reducing 480 inter-cell interference based on the message.

[0050] The method(s) as presented herein enable(s) more efficient handling of multi- cell resource allocation and/or inter-cell interference management for users with deterministic traffic patterns. The methods enable proactive, or up-front, coordination, as well as reactive mechanisms that act on detected interference problems.

[0051] The method(s) may take system dynamics that cause time-variant behaviours into account. For example, the method(s) may be used in cases when e.g. new communication links, e.g. gNB-2-UE, are setup, and/or existing ones are terminated, and/or when UEs are moving and experiencing e.g. handovers.

[0052] The method(s) enable(s) to ensure that SPS/CG allocations for difference users are done such that inter-cell interference is reduced or minimized, or at least managed to the extent that is tolerable. In case of detected interference problems, the method(s) may quickly overcome the interference problems e.g. by utilizing a-priori knowledge of the deterministic traffic patterns and all interference relations.

[0053] The messages comprising time-frequency resource allocation characteristics for user equipments, i.e. the information exchanged per UE over Xn between the network nodes, e.g. gNBs, may comprise e.g. the following information:

Time- frequency grid resource allocation for uplink (UL) and/or downlink (DL). This may comprise modulation and coding scheme (MCS) allocation. This information may be the same as is configured for the UE using RRC signalling and potentially DCI.

UE measurement of its dominant interferer ratio (DIR), e.g. average DIR. This may comprise the Cell ID of the dominant interferer (DI).

For DL allocations: multiple input multiple output setting of the network node, i.e. the gNB MIMO setting. This may include the rank of the transmission, and for cases with gNB beamforming also the used Beam Index.

For UL allocations: (i) uplink transmission power control (PC) setting of the UE, i.e. the UEs UL Tx PC setting. The PC parameter setting may comprise e.g. the parameter values for Alpha and/or Po as per the 3GPP defined UE power control transmission equation (ii) multiple input multiple output setting of the user equipment transmission i.e. the UE Tx MIMO setting, (iii) uplink reception configuration of the network node, i.e. the gNB UL reception configuration, e.g. in the form of Beam Index.

[0054] Exchanging information means that the network nodes send or transmit information to each other and/or receive information from each other.

[0055] The above listed information, or at least one of the listed elements, may be captured as information elements in a new Xn based procedure for signalling. This signalling may be named “Extended Semi Persistent Scheduling or Configured Grant transmission and reception configuration” i.e. “Extended SPS/CG Tx and Rx configuration”. The Extended SPS/CG Tx and Rx configuration may be signalled by default over the Xn interface to the neighboring network nodes or cells, e.g. gNBs, that corresponds to the UEs dominant interferer, but may also be signalled to other cells, e.g. gNBs. The Extended SPS/CG Tx and Rx configuration expresses the UEs time- frequency resource allocation characteristics, or time-frequency-space resource allocation characteristics.

[0056] Fig. 5 shows, by way of an example, a signalling flow diagram 500. A first network node 510 is the gNB#l and a second network node 520 is the gNB#2. The first network node 510 and the second network node 520 have exchanged 530 a message comprising time- frequency resource allocation characteristics for one or more user equipments (UEs). In other words, the gNB#l and gNB#2 have exchanged Extended SPS/CG Tx and Rx configuration for their RRC connected users. The users, or UEs, may be subject to interference from the first and/or second network nodes 510, 520.

[0057] The gNB#l may set up a connection for a new UE. In other words, a new UE may be configured 540 for cell on gNB#l. For example, this new UE may be a user equipment that moves from another state, such as RRC Idle or RRC Inactive to RRC Connected state, which may then require a deterministic data flow allocation. The gNB#l may share the Extended SPS/CG Tx and Rx configuration for the new UE with the gNB#2. The new UE may have a cell on the gNB#2 as its dominant interferer (DI). Thus, the time- frequency resource allocation characteristics for the new UE may be selected by the serving cell to reduce interference from the second network node. For example, the gNB#l may select 550, for the new UE, an SPS pattern subject to minimum interference from gNB#2. The Extended SPS/CG Tx and Rx configuration for the new UE may be signalled 560 from the gNB#l to the gNB#2. As the gNBs exchange the message Extended SPS/CG Tx and Rx configuration and know the user’s time-frequency domain allocation patterns in different cells, they are able to allocate time- frequency resource allocation patterns based on that message for new arriving user(s). This way, the interference coupling between users, or inter-cell interference, may be minimized, or reduced.

[0058] Fig. 6 shows, by way of an example, a signalling flow diagram 600. The first network node 610 and the second network node 620 have exchanged 630 a message comprising time- frequency resource allocation characteristics for one or more user equipments (UEs). In other words, the gNB#l and gNB#2 have exchanged Extended SPS/CG Tx and Rx configuration for their RRC connected users. The users, or UEs, may be subject to interference from the first and/or second network nodes 610, 620. In this example, a gNB, e.g. gNB#l, modifies 640 the resource allocation for one of the users. For example, this user has previously been configured with a certain SPS/CG resource allocation pattern. The gNB#l decides to modify the SPS/CG allocation for the user, e.g. by sending a new DCI and modifying e.g. the frequency-domain allocation or MCS. This new DCI configuration for an existing UE related to its SPS and/or CG Type-2 configuration may then be signalled 660 over the Xn interface to the gNB#2. This way, the gNB#2 is made aware of the modified configuration for the UE. Thus, in response to the first network node modifying the time- frequency resource allocation for one of the one or more user equipments, a message comprising at least the modified time- frequency resource allocation, e.g. a new DCI configuration described above, may be sent to the second network node.

[0059] Fig. 7 shows by way of an example, a signalling flow diagram 700. In this example, one network node may be designated as a coordinator network node of a cluster of network nodes. The coordinator network node may be a master network node Master gNB 730. The cluster of network nodes may comprise the first network node 710 and the second network node 720, and the master network 730 node acting as a local coordinator. The first network node and the second network node and the coordinator network node have exchanged 740 a message comprising time- frequency resource allocation characteristics for one or more user equipments (UEs). In other words, the gNB#l and gNB#2 and Master gNB have exchanged Extended SPS/CG Tx and Rx configuration for their RRC connected users. The users, or UEs, may be subject to interference from the first and/or second network nodes. The coordinator network node is in charge of making sure that the resource allocations, e.g. SPS/CG time-frequency resource allocations, are as effectively coordinated as possible in order to ensure minimum interference coupling.

[0060] When a new UE is being added at gNB#l, it may happen that the new UE may require to allocate time and frequency resources in gNB#l that may be already allocated at gNB#2. The Master gNB has the information on SPS/CG time and frequency allocation on both gNB#l and gNB#2. When the new proposed time and frequency allocation in gNB#l is sent to the Master gNB, it may detect that the proposed allocation is not damaging previously existing SPS/CG time- frequency allocations in gNB#2 and hence can be granted. Alternatively, it may detect that the proposed allocation will damage previously existing allocations in gNB#2. Therefore, some adaptation may need to be done on the proposed time- frequency allocation. This is explained further in the following with reference to Fig. 7.

[0061] The gNB#l may set up a connection for a new UE. In other words, a new UE may be configured 750 for cell on gNB#l. For example, this new UE may be a user equipment that moves from another state, such as RRC Idle or RRC Inactive to RRC Connected state, which may then require a deterministic data flow allocation. The gNBs, e.g. the gNB#l, may propose Extended SPS/CG Tx and Rx configuration for their UEs, e.g. the new UEs. Before the new configuration is taken into use, the gNB may transmit a message comprising time-frequency resource allocation characteristics for the new UE, i.e. signal 760 the Extended SPS/CG Tx and Rx configuration for the new UE, to a coordinator network node of a cluster of network nodes, i.e. to the Master gNB, for confirmation.

[0062] The Master gNB may transmit to the gNB#l a confirmation message as a response message comprising the confirmation. The confirmation message may comprise a confirmation that the message comprising time- frequency resource allocation characteristics for the new UE may be taken into use and/or transmitted to the second network node, e.g. the gNB#2.

[0063] Alternatively, the Master gNB may respond with an information message comprising a request to use different time-frequency resource allocation characteristics for the new UE. [0064] To summarize, the Master gNB may respond 770 with two possible response messages: i) CONFIRM, i.e. a confirmation that the message comprising time-frequency resource allocation characteristics for the new user equipment can be taken into use and/or transmitted to the second network node or ii) INFORM to use a different Extended SPS/CG Tx and Rx configuration for the new UE.

[0065] In response to receiving CONFIRM, the gNBs may take the Extended SPS/CG Tx and Rx configuration into use and/or transmit it to the second network node. In response to receiving INFORM, the gNB may configure new time-frequency resource allocation characteristics for the new UE. The gNB may propose a different configuration and send the different configuration for confirmation to the coordinator network node. Alternatively, the Master gNB may configure a different time- frequency resource allocation characteristics to be used for the new UE. When the gNB#l have received the proposed configuration by the Master gNB, the gNB#l may transmit a confirmation message to the Master gNB that it will use the new pattern proposed by the Master gNB.

[0066] When the new configurations are confirmed by the coordinator network node, it may be assured that the resource allocations are effectively coordinated.

[0067] As the traffic load increases in the system, there may be more and more inter cell interference. This may happen, even though the network nodes have exchanged the information on the resource allocation characteristics, i.e. the Extended SPS/CG Tx and Rx configuration for their UEs, so that the network nodes may smartly allocate the radio resource patterns for their users. Fig. 8 shows by way of an example, a signalling flow diagram 800. The first network node 810 and the second network node 820 have exchanged a message comprising time-frequency resource allocation characteristics for one or more user equipments (UEs). In other words, the gNB#l and gNB#2 have exchanged 830 Extended SPS/CG Tx and Rx configuration for their RRC connected users. The users, or UEs, may be subject to interference at least from the first and/or second network nodes. A network node, e.g. the gNB#l, may detect 840 that the one of the one or more user equipments is subject to interference that is above a pre-defined threshold, i.e. subject to too high interference in the uplink. Too high interference may start to cause problems. For example, the gNB may start to fail decoding of uplink transmissions from the user. [0068] The network node may measure the uplink received interference for the resources where different users are being allocated. In addition, the network node may measure the received power level from a desired user. If the ratio of the received power level from the desired user and the interference, i.e. signal to interference ratio, is too low, the network node knows that the interference is too high. Depending on the used MSC, the network node knows which signal to interference ratio is required to have reliable detection of too high interference that is above a pre-defined threshold.

[0069] The gNB#l knows which user or users are causing this interference as it knows the radio resource allocation patterns for users in neighboring cells, since the network nodes have exchanged the Extended SPS/CG Tx and Rx configuration for their users. The user causing the interference is an aggressor user equipment. Thus, the gNB#l may determine 850 an aggressor user equipment based on the message exchanged between the first network node, e.g. the gNB#l, and the second network node, e.g. the gNB#2. The UE that causes the interference that is too high may be served by the gNB#2.

[0070] The gNB#l may transmit 860 a request to the gNB#2 to reduce interference caused by the aggressor user equipment towards the gNB#l. In response to receiving the request, the gNB#2 may take actions 870 to reduce the interference from the aggressor user equipment. These actions may comprise e.g. adjustments for the aggressor UE, or re allocation of the aggressor UE to use a different radio resource allocation pattern. Adjustments for the aggressor UE may comprise e.g. reducing the aggressor user equipment’s transmission power, and/or adjusting the multiple input multiple output transmission configuration of the aggressor user equipment.

[0071] Fig. 9a shows by way of an example, a signalling flow diagram 900. The first network node 910 and the second network node 920 have exchanged a message comprising time- frequency resource allocation characteristics for one or more user equipments (UEs). In other words, the gNB#l and gNB#2 have exchanged 940 Extended SPS/CG Tx and Rx configuration for their RRC connected users. The users, or UEs, may be subject to interference from the network nodes. For example, a victim UE 930, served by e.g. gNB#l, may experience a deterministic interference pattern which is repeatedly interfered by the same signal transmission from e.g. gNB#2. Since the gNB#l and the gNB#2 have exchanged or shared the Extended SPS/CG Tx and Rx configuration for their users, the gNB#l may determine 950 based on the message exchange that a certain victim UE in its serving is subject to interference from gNB#2. The gNB#2 knows, based on the message exchange, on which Physical Resource Blocks (PRBs) the victim UE that it is serving is experiencing interference, and/or what are the characteristics of the interference. For example, the gNB#l may know the characteristics of the interference, such as used MSC, Rank, Beam etc.

[0072] The gNB#l may transmit 960 the characteristics of the interference coming from the gNB#2 to the victim UE. Transmission of this a-priori information on the interference characteristics may be sent to the victim UE using RRC signalling or other methods. The assistant signalling comprises information expressing the characteristics of the experienced deterministic interferences. The interference characteristics may comprise information corresponding to the list of Extended SPS/CG Tx and Rx configuration, i.e. at least one of

UE measurement of its dominant interferer ratio (DIR), e.g. average DIR. This may comprise the Cell ID of the dominant interferer (DI). The dominant interferer in this example may be the gNB#2.

[0073] Sending this a-priori information on the interference characteristics to the victim UE enables the victim UE to exploit 970 the received a-priori information on the interference characteristics to perform enhanced interference cancellation (IC) and/or interference mitigation (IM). The IM may be non-linear or linear, or a combination of those. The more information a UE has on the interference, the better will be its receiver performance as it may exploit the knowledge on the interference. For linear receivers, the UE may exploit such information to acquire a better estimate of the interference covariance matrix, and hence for estimation of which combined weights to use. For UEs with non linear receivers, the a-priori knowledge of the dominant interferer makes estimation of interference prior to cancellation more reliable. Thus, the UE receiver performance is improved.

[0074] The a-priori information on the interference characteristics received by assistant signalling that the victim UE may exploit for advanced receiver processing comprises a lot more useful information when compared e.g. to LTE Network Assisted Interference Cancellation and Suppression (NAICS), wherein the assistant information may comprise only a number of antennas and cell ID of the aggressor cell.

[0075] Fig. 9b shows, by way of an example, a flow graph of a method 980 for reducing inter-cell interference. The phases of the illustrated method may be performed in a user equipment, e.g. the victim UE which is served by the first network node and subject to interference at least from the second network node, or in a control device configured to control the functioning thereof, when installed therein. The method 980 comprises receiving 982, by a victim user equipment served by a first network node and subject to interference at least from a second network node, a message from the first network node comprising interference characteristics of the interference from the second network node. The method 980 comprises performing interference cancellation and/or interference mitigation based on the received interference characteristics. The interference characteristics may comprise information corresponding to the list of Extended SPS/CG Tx and Rx configuration, which is described above.

[0076] Fig. 10 shows, by way of an example, a signalling flow diagram 1000 of a centralized network architecture with a higher-layer central unit - distribute unit (CU-DU) split. As described along with the Fig. 2, the CU and DU(s) are connected via FI interfaces. The CU 1010 may be a coordinator network node, i.e. a master for coordinating SPS/CG time- frequency resource grid allocations for all the UEs 1030 with deterministic data flows in a cluster of cells, i.e. DUs 1020, controlled by the CU. The CU and the DUs may form a network node such as a gNB#l and/or a gNB#2. The UE in this example may be named as a second user equipment.

[0077] The CU 1010 may host the RRC entity. New UE allocation may be set up 1040 with SPS/CG pattern triggered for a UE 1030, which may be a second UE. The CU may be able to directly configure 1045 a UE with the desired time-periodicity of their respective SPS/CG resource allocations. For Type 1 CG, the CU may also configure the frequency-domain resources and MCS by means of RRC signalling.

[0078] The DU may host the PHY/MAC/RLC, and hence the functionality for sending 1050 DCI to the UEs. The DCI may activate the SPS pattern for UEs and set their MCS. In case of CG Type 2 as well, activation of uplink resources may be activated by means of DCI.

[0079] For SPS and/or CG allocations, the CU 1010 may signal 1060 the time- periodicity of the allocation to the DU 1020 that hosts the UE 1030. Similarly, the CU 1010 may inform 1065 the UE of the payload size and desired start time. The DU may respond 1070 with confirmation and a number of required PRBs that it will allocate to the UE. The DU may at first decide on its own the PRBs that it allocates for the SPS and/or CG pattern for the UE. Alternatively, the CU may instruct 1080 the DU to use certain PRBs. This enables the CU to perform frequency- domain coordination of SPS/CG patterns between the cells (DUs).

ACRONYMS LIST

IIoT Industrial internet of things

FoF Factories of the future TSC Time- sensitive communications TSN Time- sensitive networking SPS Semi persistent scheduling CG Configured grant NR New radio RRC Radio resource control DCI Downlink control information

CS-RNTI Configured Scheduling - Radio Network Temporary Identifier MCS Modulation and coding scheme

UE User equipment

NG-RAN Next generation radio access network CU Central unit DU Distributed unit ICIC Inter-cell interference coordination URLLC Ultra-reliable low latency communications UL Uplink DL Downlink DIR Dominant interferer ratio DI Dominant interferer

MIMO Multiple input multiple output

PRB Physical resource block

IC Interference cancellation IM Interference mitigation

Claims

CLAIMS:

1. An apparatus which is a second network node comprising means for:

- receiving, from a first network node, a message comprising time- frequency resource allocation characteristics for one or more user equipments served by the first network node, wherein the one or more user equipments served by the first network node is subject to interference at least from the second network node; and/or

- transmitting, to the first network node, a message comprising time-frequency resource allocation characteristics for one or more user equipments served by the second network node, wherein the one or more user equipments served by the second network node is subject to interference at least from the first network node; and

- reducing inter-cell interference based on the message.

2. The apparatus of claim 1, further comprising means for receiving a message comprising time- frequency resource allocation characteristics for a new user equipment served by the first network node, wherein the new user equipment has the second network node as its dominant interferer, and wherein the time- frequency resource allocation characteristics for the new user equipment have been selected to reduce interference from the second network node; and allocating time- frequency resources for the new user equipment based on the received message for the new user equipment.

3. The apparatus of any preceding claim, further comprising means for receiving, in response to the first network node modifying the time- frequency resource allocation for one of the one or more user equipments served by the first network node, a message comprising at least the modified time- frequency resource allocation.

4. The apparatus of any preceding claim, further comprising means for receiving a request from the first network node to reduce interference caused by an aggressor user equipment towards the first network node, wherein the aggressor user equipment is served by the second network node; reducing the interference from the aggressor user equipment based on the request.

5. The apparatus of claim 4, wherein the reducing the interference from the aggressor user equipment comprises adjusting the aggressor user equipment’s transmission power; and/or adjusting the multiple input multiple output transmission configuration of the aggressor user equipment; and/or

- re-allocating the time- frequency resources of the aggressor user equipment.

6. An apparatus which is a first network node comprising means for:

- transmitting, to a second network node, a message comprising time- frequency resource allocation characteristics for one or more user equipments served by the first network node, wherein the one or more user equipments served by the first network node is subject to interference at least from the second network node; and/or

- receiving, from the second network node, a message comprising time- frequency resource allocation characteristics for one or more user equipments served by the second network node, wherein the one or more user equipments served by the second network node is subject to interference at least from the first network node; and reducing inter-cell interference based on the message.

7. The apparatus of claim 6, further comprising means for setting up a connection for a new user equipment which has the second network node as its dominant interferer; selecting time- frequency resource characteristics for the new user equipment to reduce interference from the second network node; and transmitting a message comprising time- frequency resource allocation characteristics for the new user equipment to the second network node.

8. The apparatus of claim 6 or 7, further comprising means for modifying the time- frequency resource allocation for one of the one or more user equipments served by the first network node; and transmitting a message comprising at least the modified time- frequency resource allocation to the second network node.

9. The apparatus of any of the claims 6 to 8, further comprising means for setting up a connection for a new user equipment; transmitting a message comprising time- frequency resource allocation characteristics for the new user equipment to a coordinator network node of a cluster of network nodes; receiving a confirmation message from the coordinator network node, the confirmation message comprising a confirmation that the message comprising time- frequency resource allocation characteristics for the new user equipment can be taken into use and/or transmitted to the second network node; or receiving an information message from the coordinator network node, the information message comprising a request to use different time-frequency resource allocation characteristics for the new user equipment.

10. The apparatus of claim 9, further comprising means for taking, in response to receiving the confirmation message, into use the time-frequency resource allocation characteristics for the new user equipment and/or transmitting, in response to receiving the confirmation message, the message comprising time- frequency resource allocation characteristics for the new user equipment to the second network node; or configuring, in response to receiving the information message, new time-frequency resource allocation characteristics for the new user equipment.

11. The apparatus of any of the claims 6 to 10, further comprising means for detecting that one of the one or more user equipments is subject to interference that is above a pre-defmed threshold; determining an aggressor user equipment served by the second network node based on the message received from the second network node; and transmitting a request to the second network node to reduce interference caused by the aggressor user equipment towards the first network node.

12. The apparatus of any of the claims 6 to 11, further comprising means for detecting that one of the one or more user equipments served by the first network node is a victim user equipment subject to interference from the second network node based on the message received from the second network node; determining interference characteristics of the interference from the second network node based on the message received from the second network node; and transmitting the interference characteristics to the victim user equipment.

13. The apparatus of claim 12, wherein the interference characteristics comprise at least one of time-frequency grid resource allocation for uplink and/or downlink; user equipment measurement of its dominant interferer ratio (DIR); multiple input multiple output setting of the network node for downlink allocations; uplink transmission power control setting of the user equipment and/or multiple input multiple output setting of the user equipment transmission and/or uplink reception configuration of the network node for uplink allocations.

14. The apparatus of any preceding claim, wherein the message is Extended Semi Persistent Scheduling or Configured Grant transmission and reception configuration information signalled over Xn interface.

15. The apparatus of any preceding claim, wherein the message is indicative of at least one of

- time- frequency grid resource allocation for uplink and/or downlink;

- user equipment measurement of its dominant interferer ratio (DIR);

- multiple input multiple output setting of the network node for downlink allocations;

- uplink transmission power control setting of the user equipment and/or multiple input multiple output setting of the user equipment transmission and/or uplink reception configuration of the network node for uplink allocations.

16. The apparatus of claim 15, wherein the UE measurement of its DIR comprises a cell identity of a dominant interferer.

17. The apparatus of claim 15 or 16, wherein the multiple input multiple output settings of the network node for downlink allocations comprise rank of the transmission and optionally a beam index.

18. The apparatus of any of the claims 15 to 17, wherein the power control setting comprises Alpha and/or Po.

19. The apparatus of any of the claims 15 to 18, wherein the uplink reception configuration of the network node comprises a beam index.

20. An apparatus of any preceding claim, comprising a central unit and one or more distributed unit, the central unit comprising means for configuring a second user equipment served by the distributed unit with a desired time- periodicity of resource allocations; transmitting, to the distributed unit, a message comprising time-periodicity of the resource allocation; receiving, from the distributed unit, a message comprising a number of required physical resource blocks that it will allocate to the second user equipment; and transmitting, to the distributed unit, a message comprising instruction for the distributed unit to use certain physical resource blocks.

21. An apparatus which is served by the first network node of any of the claims 6 to 19, and subject to interference at least from the second network node of any of the claims 1 to 5 or 14 to 19, comprising means for receiving a message from the first network node comprising interference characteristics of the interference from the second network node; and perform interference cancellation and/or interference mitigation based on the received interference characteristics.

22. The apparatus of any preceding claim, wherein the means comprises at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

23. A method, comprising

- receiving, by a second network node from a first network node, a message comprising time-frequency resource allocation characteristics for one or more user equipments served by the first network node, wherein the one or more user equipments served by the first network node is subject to interference at least from the second network node; and/or

- transmitting, by the second network node to the first network node, a message comprising time-frequency resource allocation characteristics for one or more user equipments served by the second network node, wherein the one or more user equipments served by the second network node is subject to interference at least from the first network node; and

- reducing inter-cell interference based on the message.

24. The method of claim 23, further comprising receiving a message comprising time- frequency resource allocation characteristics for a new user equipment served by the first network node, wherein the new user equipment has the second network node as its dominant interferer, and wherein the time- frequency resource allocation characteristics for the new user equipment have been selected to reduce interference from the second network node; and allocating time- frequency resources for the new user equipment based on the received message for the new user equipment.

25. The method of any preceding method claim, further comprising receiving, in response to the first network node modifying the time- frequency resource allocation for one of the one or more user equipments served by the first network node, a message comprising at least the modified time- frequency resource allocation.

26. The method of any preceding method claim, further comprising receiving a request from the first network node to reduce interference caused by an aggressor user equipment towards the first network node, wherein the aggressor user equipment is served by the second network node; and reducing the interference from the aggressor user equipment based on the request.

27. The method of claim 26, wherein the reducing the interference from the aggressor user equipment comprises adjusting the aggressor user equipment’s transmission power; and/or adjusting the multiple input multiple output transmission configuration of the aggressor user equipment; and/or

- re-allocating the time- frequency resources of the aggressor user equipment.

28. A method, comprising: transmitting, by a first network node to a second network node, a message comprising time- frequency resource allocation characteristics for one or more user equipments served by the first network node, wherein the one or more user equipments served by the first network node is subject to interference at least from the second network node; and/or

29. The method of claim 28, further comprising setting up a connection for a new user equipment which has the second network node as its dominant interferer; selecting time- frequency resource characteristics for the new user equipment to reduce interference from the second network node; and transmitting a message comprising time- frequency resource allocation characteristics for the new user equipment to the second network node.

30. The method of claim 28 or 29, further comprising modifying the time- frequency resource allocation for one of the one or more user equipments served by the first network node; and transmitting a message comprising at least the modified time- frequency resource allocation to the second network node.

31. The method of any of the claims 28 to 30, further comprising setting up a connection for a new user equipment; transmitting a message comprising time- frequency resource allocation characteristics for the new user equipment to a coordinator network node of a cluster of network nodes; receiving a confirmation message from the coordinator network node, the confirmation message comprising a confirmation that the message comprising time- frequency resource allocation characteristics for the new user equipment can be taken into use and/or transmitted to the second network node; or receiving an information message from the coordinator network node, the information message comprising a request to use different time-frequency resource allocation characteristics for the new user equipment.

32. The method of claim 31 , further comprising taking, in response to receiving the confirmation message, into use the time-frequency resource allocation characteristics for the new user equipment and/or transmitting, in response to receiving the confirmation message, the message comprising time- frequency resource allocation characteristics for the new user equipment to the second network node; or configuring, in response to receiving the information message, new time-frequency resource allocation characteristics for the new user equipment.

33. The method of any of the claims 28 to 32, further comprising detecting that one of the one or more user equipments is subject to interference that is above a pre-defined threshold; determining an aggressor user equipment served by the second network node based on the message received from the second network node; and transmitting a request to the second network node to reduce interference caused by the aggressor user equipment towards the first network node.

34. The method of any of the claims 28 to 33, further comprising detecting that one of the one or more user equipments served by the first network node is a victim user equipment subject to interference from the second network node based on the message received from the second network node; determining interference characteristics of the interference from the second network node based on the message received from the second network node; and transmitting the interference characteristics to the victim user equipment.

35. The method of claim 34, wherein the interference characteristics comprise at least one of time- frequency grid resource allocation for uplink and/or downlink; user equipment measurement of its dominant interferer ratio (DIR); multiple input multiple output setting of the network node for downlink allocations; uplink transmission power control setting of the user equipment and/or multiple input multiple output setting of the user equipment transmission and/or uplink reception configuration of the network node for uplink allocations.

36. The method of any preceding method claim, wherein the message is Extended Semi Persistent Scheduling or Configured Grant transmission and reception configuration information signalled over Xn interface.

37. The method of any preceding method claim, wherein the message is indicative of at least one of

- time- frequency grid resource allocation for uplink and/or downlink;

- user equipment measurement of its dominant interferer ratio (DIR);

38. The method of claim 37, wherein the UE measurement of its DIR comprises a cell identity of a dominant interferer.

39. The method of claim 37 or 38, wherein the multiple input multiple output settings of the network node for downlink allocations comprise rank of the transmission and optionally a beam index.

40. The method of any of the claims 37 to 39, wherein the power control setting comprises Alpha and/or Po.

41. The method of any of the claims 37 to 40, wherein the uplink reception configuration of the network node comprises a beam index.

42. The method of any preceding method claim, further comprising configuring, by a central unit comprised in a first and/or second network node, a second user equipment with a desired time-periodicity of resource allocations, wherein the second user equipment is served by a distributed unit comprised in a first and/or second network node; transmitting, to the distributed unit, a message comprising time-periodicity of the resource allocation; receiving, from the distributed unit, a message comprising a number of required physical resource blocks that it will allocate to the second user equipment; and transmitting, to the distributed unit, a message comprising instruction for the distributed unit to use certain physical resource blocks.

43. A method comprising - receiving, by a victim user equipment served by a first network node and subject to interference at least from a second network node, a message from the first network node comprising interference characteristics of the interference from the second network node; and performing interference cancellation and/or interference mitigation based on the received interference characteristics.