WO2025026696A1

WO2025026696A1 - Apparatus, method, and computer program

Info

Publication number: WO2025026696A1
Application number: PCT/EP2024/069786
Authority: WO
Inventors: Klaus Ingemann Pedersen; Erika PORTELA LOPES DE ALMEIDA; Roberto Maldonado
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2023-08-03
Filing date: 2024-07-12
Publication date: 2025-02-06
Anticipated expiration: 2026-02-03
Also published as: GB2632322A; GB202311939D0

Abstract

There is provided an apparatus, method and computer program for causing an apparatus to perform receiving from a first access node, signalling comprising a first slot configuration comprising concurrent uplink and downlink transmission opportunities between the first access node and a user equipment served by the first access node, wherein the apparatus is comprised in a second access node.

Description

APPARATUS, METHOD, AND COMPUTER PROGRAM

Field of the disclosure

[0001] The examples described herein generally relate to apparatus, methods, and computer programs, and more particularly (but not exclusively) to apparatus, methods and computer programs for apparatuses.

Background

[0002] A communication system can be seen as a facility that enables communication sessions between two or more entities such as communication devices, base stations and/or other nodes by providing carriers between the various entities involved in the communications path.

[0003] The communication system may be a wireless communication system. Examples of wireless systems comprise public land mobile networks (PLMN) operating based on radio standards such as those provided by 3GPP, satellite based communication systems and different wireless local networks, for example wireless local area networks (WLAN). The wireless systems can typically be divided into cells, and are therefore often referred to as cellular systems.

[0004] The communication system and associated devices operate in accordance with a given set of standards or specifications that set out what the various entities associated with the system are permitted to do and how that is to be achieved. Communication protocols and/or parameters that are to be used for the connection are also typically defined. Examples of standards are the so-called 5G standards.

Summary

[0005] According to a first aspect, there is provided an apparatus comprising means for: receiving, from a first access node, signalling comprising a first slot configuration comprising concurrent uplink and downlink transmission opportunities between the first access node and a user equipment served by the first access node, wherein the apparatus is comprised in a second access node.

[0006] The apparatus may further comprise means for: determining an interference mitigation mechanism to be deployed by the apparatus during a time slot based on the indicated first slot configuration; and causing the interference mitigation mechanism to be deployed.

[0007] The interference mitigation mechanism may comprise at least one of: adjusting a power level to be used for an uplink and/or downlink transmission opportunity scheduled by the apparatus; adjusting a timing of an uplink and/or downlink transmission opportunity scheduled by the apparatus; signalling the first access node to request that the first access node adjusts a power level to be used for at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; signalling the first access node to request that the first access node adjusts a timing of at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; or signalling the first access node to request that the first access node abstains from scheduling an uplink and/or downlink transmission opportunity during the time slot.

[0008] The apparatus may further comprise means for: receiving, from the first access node, an indication that the first access node will schedule transmissions associated with a reduced power throughout a time duration; and prioritizing uplink signalling and/or higher priority traffic between the second access node and a user equipment throughout the time duration based on the received indication.

[0009] According to a second aspect, there is provided an apparatus comprising means for: transmitting, to a second access node, signalling comprising a first slot configuration comprising concurrent uplink and downlink transmission opportunities between the apparatus and a user equipment served by the apparatus, wherein the apparatus is comprised in a first access node.

[0010] The apparatus may further comprise means for: receiving, from the second access node, a request to perform at least one of the follow actions: adjust a power level to be used for at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during a time slot; adjust a timing of at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; or abstain from scheduling an uplink and/or downlink transmission opportunity during the time slot; and determining whether to perform at least one of the requested action.

[0011] According to a third aspect, there is provided an apparatus comprising: at least one processor; and at least one memory comprising code that, when executed by the at least one processor, causes the apparatus to perform: receiving, from a first access node, signalling comprising a first slot configuration comprising concurrent uplink and downlink transmission opportunities between the first access node and a user equipment served by the first access node, wherein the apparatus is comprised in a second access node.

[0012]The apparatus may further be caused to perform: determining an interference mitigation mechanism to be deployed by the apparatus during a time slot based on the indicated first slot configuration; and causing the interference mitigation mechanism to be deployed.

[0013] The interference mitigation mechanism may comprise at least one of: adjusting a power level to be used for an uplink and/or downlink transmission opportunity scheduled by the apparatus; adjusting a timing of an uplink and/or downlink transmission opportunity scheduled by the apparatus; signalling the first access node to request that the first access node adjusts a power level to be used for at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; signalling the first access node to request that the first access node adjusts a timing of at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; or signalling the first access node to request that the first access node abstains from scheduling an uplink and/or downlink transmission opportunity during the time slot. [0014] The apparatus may further be caused to perform: receiving, from the first access node, an indication that the first access node will schedule transmissions associated with a reduced power throughout a time duration; and prioritizing uplink signalling and/or higher priority traffic between the second access node and a user equipment throughout the time duration based on the received indication.

[0015] According to a fourth aspect, there is provided an apparatus comprising: at least one processor; and at least one memory comprising code that, when executed by the at least one processor, causes the apparatus to perform: transmitting, to a second access node, signalling comprising a first slot configuration comprising concurrent uplink and downlink transmission opportunities between the apparatus and a user equipment served by the apparatus, wherein the apparatus is comprised in a first access node.

[0016] The apparatus may further be caused to perform: receiving, from the second access node, a request to perform at least one of the follow actions: adjust a power level to be used for at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during a time slot; adjust a timing of at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; or abstain from scheduling an uplink and/or downlink transmission opportunity during the time slot; and determining whether to perform at least one of the requested action.

[0017] According to a fifth aspect, there is provided a method for an apparatus, the method comprising: receiving, from a first access node, signalling comprising a first slot configuration comprising concurrent uplink and downlink transmission opportunities between the first access node and a user equipment served by the first access node, wherein the apparatus is comprised in a second access node.

[0018] The method may further comprise: determining an interference mitigation mechanism to be deployed by the apparatus during a time slot based on the indicated first slot configuration; and causing the interference mitigation mechanism to be deployed. [0019] The interference mitigation mechanism may comprise at least one of: adjusting a power level to be used for an uplink and/or downlink transmission opportunity scheduled by the apparatus; adjusting a timing of an uplink and/or downlink transmission opportunity scheduled by the apparatus; signalling the first access node to request that the first access node adjusts a power level to be used for at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; signalling the first access node to request that the first access node adjusts a timing of at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; or signalling the first access node to request that the first access node abstains from scheduling an uplink and/or downlink transmission opportunity during the time slot.

[0020] The method may further comprise: receiving, from the first access node, an indication that the first access node will schedule transmissions associated with a reduced power throughout a time duration; and prioritizing uplink signalling and/or higher priority traffic between the second access node and a user equipment throughout the time duration based on the received indication.

[0021] According to a sixth aspect, there is provided an apparatus comprising means for: transmitting, to a second access node, signalling comprising a first slot configuration comprising concurrent uplink and downlink transmission opportunities between the apparatus and a user equipment served by the apparatus, wherein the apparatus is comprised in a first access node.

[0022] The method may further comprise: receiving, from the second access node, a request to perform at least one of the follow actions: adjust a power level to be used for at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during a time slot; adjust a timing of at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; or abstain from scheduling an uplink and/or downlink transmission opportunity during the time slot; and determining whether to perform at least one of the requested action. [0023] According to a seventh aspect, there is provided an apparatus comprising: receiving circuitry for receiving, from a first access node, signalling comprising a first slot configuration comprising concurrent uplink and downlink transmission opportunities between the first access node and a user equipment served by the first access node, wherein the apparatus is comprised in a second access node.

[0024] The apparatus may further comprise: determining circuitry for determining an interference mitigation mechanism to be deployed by the apparatus during a time slot based on the indicated first slot configuration; and causing the interference mitigation mechanism to be deployed.

[0025] The interference mitigation mechanism may comprise at least one of: adjusting a power level to be used for an uplink and/or downlink transmission opportunity scheduled by the apparatus; adjusting a timing of an uplink and/or downlink transmission opportunity scheduled by the apparatus; signalling the first access node to request that the first access node adjusts a power level to be used for at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; signalling the first access node to request that the first access node adjusts a timing of at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; or signalling the first access node to request that the first access node abstains from scheduling an uplink and/or downlink transmission opportunity during the time slot.

[0026] The apparatus may further comprise: receiving circuitry for receiving, from the first access node, an indication that the first access node will schedule transmissions associated with a reduced power throughout a time duration; and prioritizing circuitry for prioritizing uplink signalling and/or higher priority traffic between the second access node and a user equipment throughout the time duration based on the received indication.

[0027] According to an eighth aspect, there is provided an apparatus comprising: transmitting circuitry for transmitting, to a second access node, signalling comprising a first slot configuration comprising concurrent uplink and downlink transmission opportunities between the apparatus and a user equipment served by the apparatus, wherein the apparatus is comprised in a first access node.

[0028] The apparatus may further comprise: receiving circuitry for receiving, from the second access node, a request to perform at least one of the follow actions: adjust a power level to be used for at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during a time slot; adjust a timing of at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; or abstain from scheduling an uplink and/or downlink transmission opportunity during the time slot; and determining circuitry for determining whether to perform at least one of the requested action.

[0029] According to a ninth aspect, there is provided non-transitory computer readable medium comprising program instructions for causing an apparatus to perform: receiving, from a first access node, signalling comprising a first slot configuration comprising concurrent uplink and downlink transmission opportunities between the first access node and a user equipment served by the first access node, wherein the apparatus is comprised in a second access node.

[0030] The apparatus may further be caused to perform: determining an interference mitigation mechanism to be deployed by the apparatus during a time slot based on the indicated first slot configuration; and causing the interference mitigation mechanism to be deployed.

[0031] The interference mitigation mechanism may comprise at least one of: adjusting a power level to be used for an uplink and/or downlink transmission opportunity scheduled by the apparatus; adjusting a timing of an uplink and/or downlink transmission opportunity scheduled by the apparatus; signalling the first access node to request that the first access node adjusts a power level to be used for at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; signalling the first access node to request that the first access node adjusts a timing of at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; or signalling the first access node to request that the first access node abstains from scheduling an uplink and/or downlink transmission opportunity during the time slot.

[0032] The apparatus may further be caused to perform: receiving, from the first access node, an indication that the first access node will schedule transmissions associated with a reduced power throughout a time duration; and prioritizing uplink signalling and/or higher priority traffic between the second access node and a user equipment throughout the time duration based on the received indication.

[0033] According to a tenth aspect, there is provided non-transitory computer readable medium comprising program instructions for causing an apparatus to perform: transmitting, to a second access node, signalling comprising a first slot configuration comprising concurrent uplink and downlink transmission opportunities between the apparatus and a user equipment served by the apparatus, wherein the apparatus is comprised in a first access node.

[0034] The apparatus may further be caused to perform: receiving, from the second access node, a request to perform at least one of the follow actions: adjust a power level to be used for at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during a time slot; adjust a timing of at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; or abstain from scheduling an uplink and/or downlink transmission opportunity during the time slot; and determining whether to perform at least one of the requested action.

[0035] The following may be performed and/or apply in respect of any of the first to tenth aspects.

[0036] The signalling may comprise an indication of a first specific portion of a range of contiguous frequencies to which at least part of the indicated first slot configuration is to be applied.

[0037] The signalling may comprise: an indication that the first slot configuration further comprises a second slot configuration, wherein the second slot configuration comprises one of: uplink only transmission opportunities, downlink only transmission opportunities, or uplink and downlink transmission opportunities; and an indication of a second specific portion of the range of contiguous frequencies to which the indicated second slot configuration is to be applied.

[0038] The signalling may comprise an indication that the first access node will transmit during the indicated downlink transmission opportunities using a reduced transmission power relative to the first access node’s average transmission power.

[0039] The signalling may comprise: an indication of a third slot configuration available for use by the first access node during a time slot, wherein the first slot configuration is also indicated as being available for use by the first access node during the time slot, where the third slot configuration comprises one of: uplink only transmission opportunities, downlink only transmission opportunities, or concurrent uplink and downlink transmission opportunities; and an indication that a slot configuration that will actually be used by the first access node during the time slot for transmissions between the first access node and the user equipment will be dynamically selected by the first access node based on network conditions between the first access node and the user equipment determined at a preconfigured time.

[0040]The signalling may comprise an indication that the uplink transmission opportunities for the first slot configuration are located at one of: a lower range of frequencies than a range of frequencies associated with the downlink transmission opportunities; between two ranges of frequencies associated with the downlink transmission opportunities; and a higher range of frequencies than a range of frequencies associated with the downlink transmission opportunities.

[0041] The signalling may comprise an indication of where the uplink transmission opportunities for the first slot configuration are located by comprising an offset that represents a frequency offset from a reference resource.

[0042] The signalling may comprise an indication of a frequency bandwidth size to be used for the downlink transmission opportunities, and an indication of at least one range of frequencies of a guard band. [0043] The signalling may comprise an indication of a frequency bandwidth size to be used for the uplink transmission opportunities, and an indication of at least one range of frequencies of a guard band.

[0044] The first access node may be one of a centralized unit or a distributed unit, and the second access node may be one of a centralized unit and a distributed unit.

[0045] The signalling may be signalled via one of: an Xn interface; and an F1 interface. [0046] According to an eleventh aspect, there is provided a computer program product stored on a medium that may cause an apparatus to perform any method as described herein.

[0047] According to a twelfth aspect, there is provided an electronic device that may comprise apparatus as described herein.

[0048] According to a thirteenth aspect, there is provided a chipset that may comprise an apparatus as described herein.

Brief description of FIGs.

[0049] Some examples, will now be described, merely by way of illustration only, with reference to the accompanying drawings in which:

[0050] FIGs. 1A, 1 B, and 1 C show schematic representations of a 5G system;

[0051] FIG. 2 shows a schematic representation of a network apparatus;

[0052] FIG. 3 shows a schematic representation of a user equipment;

[0053] FIGs. 4 to 8 illustrate example slot configurations;

[0054] FIGs. 9 and 10 illustrate example signalling; and

[0055] FIGs. 11 and 12 illustrate example operations that may be performed by apparatus described herein.

Detailed

[0056] The following describes operations that may be performed in relation to signalling between neighbouring access nodes in which a first access node indicates to a neighbouring access node that that the first access node will be using a specific type of slot configuration during at least one time slot. The specific type of slot configuration may be a slot configuration for the at least one time slot in which both uplink and downlink resources are allocated for transmission and reception. For example, the specific type of slot configuration may be a Sub-band non-overlapping full duplex (SBFD) slot format. SFBD is also known as Flexible Duplex, and implements time duplex communication within a single carrier bandwidth in which transmissions in uplink and downlink simultaneously occur within different sub-bands of the carrier bandwidth.

[0057] The neighbouring access node may use this received indication to either adapt its own transmission or reception (e.g., with the aim of reducing the likelihood or degree of interference arising from transmissions made by the neighbouring or first access node), and/or to request the first access node adapts the first access node’s slot configuration (e.g., with the aim of reducing the likelihood or degree of interference arising from transmissions made by the neighbouring or first access node).

[0058] It is understood that an access node may be considered to be a neighbouring access node to a first access node when at least one of those two access nodes provides a cell in which transmissions are made that may impact (via interference) transmissions and/or receptions within a cell provided by the other access node. Throughout the following, access node, radio access node, and gNB are used interchangeably without prejudice.

[0059] In the following description of examples, certain aspects are explained with reference to devices that are often capable of communication via a wireless cellular system and mobile communication systems serving such mobile communication devices. For brevity and clarity, the following describes such aspects with reference to a 5G wireless communication system. However, it is understood that such aspects are not limited to 5G wireless communication systems, and may, for example, be applied to other wireless communication systems (for example, current 6G proposals, IEEE 802.11 , etc.). [0060] Before describing in detail the examples, certain general principles of a 5G wireless communication system are briefly explained with reference to FIGs. 1 A, 1 B, and 1 C.

[0061] 3GPP standards defined a service-based architecture in 5G, which is expected to be utilized in 6G and beyond.

[0062] In a service-based architecture, a modular framework is used in which common applications can be deployed using components from different sources and/or suppliers.

[0063] FIG. 1A shows a schematic representation of a 5G system (5GS) 100. The 5GS may comprise a user equipment (UE) 102 (which may also be referred to as a communication device or a terminal), a 5G access network (AN) (which may be a 5G Radio Access Network (RAN) or any other type of 5G AN such as a Non-3GPP Interworking Function (N3IWF) /a Trusted Non3GPP Gateway Function (TNGF) for Untrusted / Trusted Non-3GPP access or Wireline Access Gateway Function (W-AGF) for Wireline access) 104, a 5G core (5GC) 106, one or more application functions (AF) 108 and one or more data networks (DN) 110.

[0064] The 5G RAN may comprise one or more gNodeB (gNB) distributed unit functions connected to one or more gNodeB (gNB) unit functions. The RAN may comprise one or more access nodes.

[0065] The 5GC 106 may comprise one or more Access and Mobility Management Functions (AMF) 112, one or more Session Management Functions (SMF) 114, one or more authentication server functions (AUSF) 116, one or more unified data management (UDM) functions 118, one or more user plane functions (UPF) 120, one or more unified data repository (UDR) functions 122, one or more network repository functions (NRF) 128, and/or one or more network exposure functions (NEF) 124. The role of an NEF is to provide secure exposure of network services (e.g. voice, data connectivity, charging, subscriber data, and so forth) towards a 3rd party. Although NRF 128 is not depicted with its interfaces, it is understood that this is for clarity reasons and that NRF 128 may have a plurality of interfaces with other network functions. [0066] The 5GC 106 also comprises a network data analytics function (NWDAF) 126. The NWDAF is responsible for providing network analytics information upon request from one or more network functions or apparatus within the network. Network functions can also subscribe to the NWDAF 126 to receive information therefrom. Accordingly, the NWDAF 126 is also configured to receive and store network information from one or more network functions or apparatus within the network. The data collection by the NWDAF 126 may be performed based on at least one subscription to the events provided by the at least one network function.

[0067] The network may further comprise a management data analytics service (MDAS) producer or MDAS Management Service (MnS) producer. The MDAS MnS producer may provide data analytics in the management plane considering parameters including, for example, load level and/or resource utilization. For example, the MDAS MnS producer for a network function (NF) may collect the NF’s load-related performance data, e.g., resource usage status of the NF. The analysis of the collected data may provide forecast of resource usage information in a predefined future time window. This analysis may also recommend appropriate actions e.g., scaling of resources, admission control, load balancing of traffic, and so forth.

[0068] An alternate view of the 5GC is represented in FIG. 1 B. It is understood that this architecture is intended to illustrate potential components that may be comprised in a core network, and the presently described principles are not limited to core networks comprising only the described components.

[0069] FIG. 1 B shows a 5GC 106’ comprising a UPF 120’ connected to an SMF 114’ over an N4 interface. The SMF 114’ is connected to each of a UDM 122’, an NEF 124’, an NWDAF 126’, an AF 108’, a Policy Control Function (PCF) 130’, an AMF 112’, and a Charging function 132’ over an interconnect medium that also connects these network functions to each other. The 5G core 106’ further comprises a network repository function (NRF) 133’ and a network function 134’ that connect to the interconnect medium. [0070] In the examples of FIGs. 1A and 1 B, control plane functionality and common data repositories of a 5G network are delivered via a set of interconnected network functions that have access to each other’s services. For example, a service-based architecture may comprise network functions such as a Network Exposure Function (NEF), an NRF, a UDM, a Policy Control Function (PCF), and AMF, an SMF, and/or the like. These network functions may provide a service to another entity as an NF “instance”.

[0071] FIG. 1 C illustrates a 5G New Radio (5G NR) network architecture, which is also specified in 3GPP technical specification (TS) 38.401 , “Technical Specification Group Radio Access Network; NG-RAN; Architecture description”.

[0072] This network architecture of FIG. 1 C comprises a next generation Radio Access Network (NG-RAN) 101” and a 5GC 102” (which may comprise the architecture illustrated in respect of any of FIGs. 1A and 1 C). The NG-RAN 101” comprises a first access node (e.g., gNB) 103” and a second access node (e.g. gNB) 104”. The second access node 104” is illustrated as comprising a centralized unit (CU) 105”, and a first distributed unit (DU) 106” and a second DU 107”. The first and second access nodes 103”, 104” connect the NG-RAN 101” to the 5GC 102” through respective NG interfaces. The first and second DUs 106”, 107” are connected to the CU 105” through respective F1 interfaces. The CU 105” is connected to a corresponding CU in the first access node 103” (not shown) through an Xn-C interface. The Xn-C interface is an interface between gNBs that aims to coordinate the access nodes using predefined procedures as defined in 3GPP TS 38.423 (e.g., XnAP procedures).

[0073] The 5G NR architecture illustrated in FIG. 1 C allows cloud-radio access network (C-RAN) implementations with one or multiple centralized units (CU), each serving a large number of distributed units (DU). Such CU-DU options are made possible by the introduction of the two new interfaces named E1 (between the control and user plane in the CU) and F1 (between the CU and DU). These are respectively defined in:

• E1 interface: TS 38.460 (Stage 2); TS 38.463 (Stage-3)

• F1 interface: TS 38.470 (Stage 2); TS 38.473 (Stage 3) [0074] It is up to the network vendor I operator to decide on which of the available architecture options to implement and deploy. In locations with availability of fiber connections, one CU may be set to serve large number of DUs with F1 latencies of only 5-10 micro seconds. The CU may comprise Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), and/or Packet Data Convergence Protocol (PDCP) entities, while a DU may comprise Radio Link Control (RLC), Medium Access Control (MAC), and/or Physical (PHY) protocol-layers.

[0075] In order to facilitate interference mitigation between neighbouring RAN access nodes, an access node, such as a gNB, may inform its neighboring gNBs which Time Division Duplex (TDD) radio frame configurations it intends to use in its served cells over an Xn and/or F1 interface. This may be indicated to the neighbouring cells using an information element (IE) that is currently labelled as the “Intended TDD DL-UL Configuration NR” IE. As different cells provided by a gNB may use different subcarrier spacing (SCS) and cyclic prefix configurations, the aforementioned IE may comprise an indication of at least one SCS, cyclic prefix configuration, and TDD downlink-uplink (DL-UL) slot configuration that will be used by the indicating gNB.

[0076] The actual TDD radio frame configuration that will be used may be expressed as a list of slot formats. Signaling of the Intended TDD DL-UL Configuration is currently supported between two gNBs on the Xn interface, using the Xn application protocol (XnAP) (as discussed in 3GPP TS 38.423), as well as between CU and DUs using the F1 application protocol (F1AP) (as discussed in 3GPP TS 38.470).

[0077] The following Table 1 reproduces selected elements from 3GPP TS 38.423, clause 9.2.2.40 in relation to slot format that is signalled in the “Intended TDD DL-UL Configuration NR” Information element.

Table 1 Summary of selected slot configuration parameters for Xn/F1 signalling of the

Intended TDD DL-UL Configuration IE

[0078] The inter-node signaling of Intended DL-UL configuration may enable simple coordination methods to manage cross-link-interference between neighboring cells. For example, if an access node knows that a neighbouring access node is likely to be making downlink transmissions during a certain time duration, the access node may Y1 schedule its own uplink and downlink transmission opportunities so that uplink transmission opportunities avoid colliding with the downlink transmissions of the neighbouring access node and/or to avoid making higher priority transmissions while the downlink transmissions of the neighbouring access node are being performed.

[0079] FIG. 2 shows an example of a control apparatus for a communication system, for example to be coupled to and/or for controlling a station of an access system, such as a RAN node, e.g. a base station, gNB, a central unit of a cloud architecture or a node of a core network such as an Mobility Management Entity (MME) or Serving Gateway (S-GW), a scheduling entity such as a spectrum management entity, or a server or host, for example an apparatus hosting a network repository function (NRF), Network data analytics function (NWDAF), Access and Mobility Management Function (AMF), Session Management Function (SMF), Unified Data Management/Unified Data Repository (UDM/UDR), and so forth. The control apparatus may be integrated with or external to a node or module of a core network or Radio Access Network (RAN). In some examples, base stations comprise a separate control apparatus unit or module. In other examples, the control apparatus can be another network element, such as a radio network controller or a spectrum controller. The control apparatus 200 can be arranged to provide control on communications in the service area of the system. The apparatus 200 comprises at least one memory 201 , at least one data processing unit 202, 203 and an input/output interface 204. Via the interface the control apparatus can be coupled to a receiver and a transmitter of the apparatus. The receiver and/or the transmitter may be implemented as a radio front end or a remote radio head. For example, the control apparatus 200 or processor 201 can be configured to execute an appropriate software code to provide the control functions. References to “code” herein are understood to refer to software code, and vice versa.

[0080] The station of the access system may be categorised into two different types: distributed units (DUs), and centralised units (CUs).

[0081] A DU provides access node support for lower layers of the protocol stack (such as, for example, the radio link control (RLC), medium access control (MAC), and/or physical layer protocol layers). Each DU is able to support one or more cells, while each cell is able to support one or more beams.

[0082] A CU can support multiple DUs, and provides access node support for higher layers of the protocol stack within an access node (such as, for example, packet data convergence protocol (PDCP), service data adaptation protocol (SDAP), and/or radio resource control (RRC) protocol layers). The interface between a CU and a DU is labelled as an F1 interface. There is a single CU for each gNB, and CU’s belonging to multiple gNB may be implemented using a shared hardware platform.

[0083] A possible wireless communication device will now be described in more detail with reference to FIG. 3 showing a schematic, partially sectioned view of a communication device 300. Such a communication device is often referred to as user equipment (UE) or terminal. An appropriate mobile communication device may be provided by any device capable of sending and receiving radio signals. Non-limiting examples comprise a mobile station (MS) or mobile device such as a mobile phone or what is referred to as a ’smart phone’, a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle), personal data assistant (PDA) or a tablet provided with wireless communication capabilities, or any combinations of these or the like. A mobile communication device may provide, for example, communication of data for carrying communications such as voice, electronic mail (email), text message, multimedia and so on. Users may thus be offered and provided numerous services via their communication devices. Non-limiting examples of these services comprise two-way or multi-way calls, data communication or multimedia services or simply an access to a data communications network system, such as the Internet. Users may also be provided broadcast or multicast data. Nonlimiting examples of the content comprise downloads, television and radio programs, videos, advertisements, various alerts and other information.

[0084] A wireless communication device may be for example a mobile device, that is, a device not fixed to a particular location, or it may be a stationary device. The wireless device may need human interaction for communication, or may not need human interaction for communication. As described herein, the terms UE or “user” are used to refer to any type of wireless communication device.

[0085] The wireless device 300 may receive signals over an air or radio interface 307 via appropriate apparatus for receiving and may transmit signals via appropriate apparatus for transmitting radio signals. In FIG. 3, a transceiver apparatus is designated schematically by block 306. The transceiver apparatus 306 may be provided, for example, by means of a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the wireless device.

[0086] A wireless device is typically provided with at least one data processing entity 301 , at least one memory 302 and other possible components 303 for use in software code and hardware aided execution of Tasks it is designed to perform, including control of access to and communications with access systems and other communication devices. The data processing, storage and other relevant control apparatus can be provided on an appropriate circuit board and/or in chipsets. This feature is denoted by reference 304. The user may control the operation of the wireless device by means of a suitable user interface such as keypad 305, voice commands, touch sensitive screen or pad, combinations thereof or the like. A display 308, a speaker and a microphone can be also provided. Furthermore, a wireless communication device may comprise appropriate connectors (either wired or' wireless) to other devices and/or for connecting external accessories, for example hands-free equipment, thereto.

[0087] 3GPP has issued a number of releases (Rel) for defining operating communication protocols related to a communications network. Currently, objectives and work are being set in relation to Releases 18 (Rel.18) and 19 (Rel. 19).

[0088] In 5G-Advanced Release-18, there is an ongoing study item on Flexible Duplexing. As mentioned above, Flexible Duplexing relates to the use of different slot formats that comprise concurrent transmission opportunities for both uplink and downlink in the same channel. [0089] One of the new slot formats being considered for both downlink (DL) and uplink (UL) transmission opportunities between an access node and a UE is a sub-band nonoverlapping full duplexing (SBFD) slot format. Time slots that comprise an SBFD slot format comprise a mixture of uplink and downlink resources (e.g., time-frequency resources that may be used for transmission and/or reception, depending on whether the resource is for uplink or downlink).

[0090] There are a range of different types of SBFD slots that reflect different makeups of uplink and/or downlink transmission opportunities. For example, an SBFD slot may comprise downlink only transmission opportunities, uplink only transmission opportunities, and/or a mixture of uplink and downlink transmission opportunities. Further, where there is a mixture of uplink and downlink transmission opportunities, an SBFD slot may comprise uplink resources near a central frequency portion of the slot (e.g., sandwiched between downlink resources for downlink transmission resources), or at an extreme of the range of frequencies of the slot (e.g., at the lowest frequency of the slot, or at a highest frequency of the slot). In both cases, the uplink resources may be separated from the downlink resources by a guard band. A guard band may be considered as being a narrow range of frequencies that separates two ranges of wider frequency (e.g., carrier frequencies respectively associated with uplink and downlink resources) that is unused for transmission opportunities in either uplink or downlink directions.

[0091] Flexible Duplexing that includes SBFD slots is illustrated with respect to FIG. 4. [0092] FIG. 4 illustrates an example of an enhanced radio frame configuration that comprises a single DL slot followed by three SBFD slots and one UL slot. Each SBFD slot in FIG. 4 is illustrated as comprising resources (e.g., time-frequency resources) for DL transmission, guard symbols (e.g., unused resources that may denote a boundary between uplink and downlink transmissions, represented in FIG. 4 as gaps between UL and DL resources), and UL resources in the middle.

[0093] Each slot in FIG. 4 illustrates a time duration considered to comprise concurrent transmissions. For example, each of the SBFD slots comprise both UL and DL transmission opportunities on respective frequency carriers that are performed simultaneously. The SBFD slot formats with concurrent DL and UL transmission opportunities are occasionally labelled “X-slots”.

[0094] The present application identifies that it is desirable to have new inter-node signaling defined that includes cases with X-slots (e.g., SBFD slot formats). This may be desirable for enabling simple inter-cell cross link interference (CLI) management, as discussed above, in which an access node either adapts (or configures) its own transmission opportunities to reduce the likelihood of interference with a neighbouring access node.

[0095] The following proposes a mechanism for signalling the use of flexible SBFD slot formats between access nodes (e.g., over an Xn interface and/or an F1 interface).

[0096] One way in which this information may be signalled is by expanding the previously defined Slot Configuration List (see, for example, Table 1) to comprise new sets of parameters for indicating, either directly or indirectly, a new intended flexible radio frame configuration. The new intended flexible radio frame configuration may indicate a type of SBFD slot format intended to be used by the signalling access node within at least one time slot. Although described in more detail below, the new intended flexible radio frame configuration may be indicated using at least one of the parameters described below in relation to Tables 2 and 3.

[0097] The new sets of parameters may additionally comprise new options for indicating when different bandwidth parts of cell may have SBFD, UL-only, and DL-only formats at the same time, but at different frequencies. Bandwidth part is discussed in more detail below.

[0098] The new sets of parameters may also be able to indicate when certain entries in the Slot Configuration List comprise multiple options for indicating to a receiving access node that the sending access node will dynamically decide on which of those slot formats to use in dependence on current signalling load at the sending access node. For example, the new sets of parameters may be able to indicate that a first type of slot configuration is to be used in case of a first set of RAN conditions, and that a second type of slot configuration is to be used in the case of a second set of RAN conditions. This mechanism may be used to enable fully dynamic slot format selection for a subset of the slots.

[0099] The new sets of parameters may be further used to indicate a transmit power control offset for use when transmitting using DL resources in SBFD slot(s). This may indicate the use of a certain transmit power reduction for better handling gNB selfinterference challenges, which was identified as a major problem for SBFD in, for example, 3GPP TR 38.858. This information can be useful at the receiving access node as it may indicate when the receiving access node can expect lower cross link interference.

[0100] In response to a receiving access node having received the new Intended flexible radio frame configuration from a signalling access node, the receiving access node may send back a message to indicate that the received configuration is acceptable (e.g., from a cross link interference perspective), or to indicate that the receiving access node recommends some other slot configuration for use by the signalling access node.

[0101] FIGs. 5 and 6 illustrate a first example signalling of frequency information, with reference to Table 2.

[0102] FIGs. 5A to 5C illustrate three possible configurations of the SBFD slot formats for different placements of the UL resources according to a new parameter, UL subband location. This new parameter is illustrated in Table 2.

[0103]Table 2 summarizes an example of how at least one indication of an SBFD slot format may be indicated over the Xn and/or F1 interface.

Table 2 Summary of parameters forXn/F1 signaling of a single SBFD format

[0104] The amount of bits used to signal possible parameters for number of DL PRBs could potentially be further down-selected by indicating these parameter in units of subbands (e.g., groups of PRBs) in order to save number of bits to signal this. [0105] In another example, the UL resources for the SBFD slot may be explicitly given instead of the DL resources. In this other example, the DL resources may subsequently be derived as being the remaining resources (e.g., the total available resources minus those resources indicated as being for use by the UL and guard bands).

[0106]As mentioned above, FIGs. 5A to 5C illustrate three possible configurations of the SBFD slot formats for different placements of the UL resources according to a new parameter, UL sub-band location. This new parameter is illustrated in Table 2.

[0107] Each of the examples of FIGs. 5A to 5C comprise approximately two parts DL resources and one part UL resources. It is understood that this is merely illustrative, and that other ratios of uplink to downlink resources within a slot may be used. [0108] In FIG. 5A, there is provided a first SBFD format 501 that comprises UL resources 503 (including guard symbol) sandwiched between first and second downlink resources 502, 504. In other words, FIG. 5A illustrates a scenario in which UL resources are comprised in a central portion of a slot (e.g., within a central carrier frequency of the full range of frequencies of the time slot). [0109] In FIG. 5B, there is provided a second SBFD format 501’ that comprises UL resources 502’ (including guard symbol) in an upper band, and DL resources 503’ in a lower band. In other words, FIG. 5B illustrates a scenario in which UL resources are comprised in an upper portion of a slot (e.g., within a range of frequencies that includes the highest carrier frequencies for transmission opportunities of the full range of frequencies of the time slot).

[0110] In FIG. 5C, there is provided a third SBFD format 501” that comprises UL resources 503” (including guard symbol) in a lower band, and DL resources 502” in an upper band. In other words, FIG. 5C illustrates a scenario in which UL resources are comprised in a lower portion of a slot (e.g., within a range of frequencies that includes the lowest carrier frequencies for transmission opportunities of the full range of frequencies of the time slot).

[0111] As mentioned above, as the UL sub-band may be located at a variety of locations (as illustrated with respect to FIGs. 5A to 5C), the location in frequency of the uplink resources may be indicated to a receiving entity. For example, this may be illustrated using the “UL sub-band location” parameter mentioned above in relation to Table 2. This indication may simple indicate “central frequency”, “upper frequency”, or “lower frequency” to respectively indicate the examples of FIGs. 5A to 5C.

[0112] When the UL sub-band is placed in the center of the carrier (e.g., when the slot format example of FIG. 5A is used), the underlying assumption for this signaling of the SBFD format is that the two DL resource regions are equal sized, in range of carrier frequencies and so are the two guard bands between the DL and UL bands. The frequency span of each DL sub-band and each guard band may be respectively defined by the IE Number of PRBs for downlink in SBFD symbols and Number of guard Physical Resource Blocks (PRBs). There is no explicit parameter in Table 2 to express the bandwidth of the UL region. However, the bandwidth of the UL region may be derived as the carrier bandwidth minus 2 times the bandwidth for the DL and guard band regions. In another example, the UL resources for the SBFD slot may be explicitly given, while the DL resources are then derived as being the remaining resources, minus those for the guard band.

[0113] When the UL sub-band is placed at the lower part or the upper part of the carrier (e.g., when the slot format example of any of FIGs. 5B and 5C are used, as indicated by the “UL sub-band location” parameter), there may be provided a single DL sub-band and a single guardband. In this case, the bandwidth of the UL region may be derived as the carrier bandwidth minus the bandwidth for the DL (Number of PRBs for downlink in SBFD symbols) and guard band regions (Number of guard PRBs)

[0114] As illustrated in Table 2, a power offset for the DL resources in the SBFD slot can be comprised in the signalling. This power offset may indicate a potential transmit power reduction in decibels of the downlink resource elements as compared to the gNBs nominal transmit power per resource element. This may be useful to help mitigate self-interference arising at the gNB (e.g., for DL to UL interference leakage experienced by the gNB) and also the gNB-2-gNB cross link interference.

[0115] As mentioned above, it is useful to let a gNB’s (“signalling gNB”) neighbouring gNBs (“receiving gNBs”) know when such a power offset is being applied by the signalling gNB for crosslink interference mitigation mechanism. For example, a gNB that determines that a neighbouring gNB will transmit to at least one UE using a lower power (relative to the neighbouring gNBs average transmission power to its UEs) during a first time frame may, for transmissions between that gNB and at least one UE, configure transmissions having a higher relative priority during that first time frame to make it more likely that the higher relative priority signalling will be received.

[0116] As another example, if the receiving gNB determines that a neighbouring gNB will transmit downlink signalling during a time duration in which the receiving gNB intends to transmit and/or receive relatively higher priority signalling (relative to all signalling of the receiving gNB), the receiving gNB may rearrange a time instance at which this higher priority signalling is performed, and/or request that the neighbouring gNB adjust its downlink transmission signalling to reduce the likelihood of crosslink interference. When a receiving gNB requests that a neighbouring gNB adjusts the neighbouring gNB’s transmission scheduling, the neighbouring gNB may be configured to determine whether the receiving gNB is associated with a higher priority with the neighbouring gNB (e.g., the receiving CU may be determined to be associated with a higher priority when the receiving gNB is a CU and the neighbouring gNB is a DU associated with that CU). When the receiving gNB is determined to be associated with a higher priority, the neighbouring DU may adjust its transmission schedule in accordance with the received request from the receiving gNB.

[0117] Other advantages of the presently described system may be realized in connection with bandwidth parts (BWPs).

[0118] A BWP is a set of contiguous physical resource blocks selected from a contiguous subset of common resource blocks on a given carrier.

[0119] Further, a BWP mechanism is a mechanism for configuring a frequency band into multiple segments (e.g., “parts”) and for switching amongst at least two of the configured BWPs depending on the current signalling situation. BWPs do not need to be contiguous, and may even partially overlap in their respective associated range of frequencies. NR currently supports multiple Bandwidth Part (BWP) Configuration within a cell.

[0120] There are roughly 3 ways of BWP switching: Timer-based, DCI-based, and RRC-Based. It takes a predetermined amount of time to switch between BWPs, with the minimum switching time being determined by a UE capability that is provided to a 5G network as part of a UE’s capability Information during registration of the UE with the network. The BWP being used may be switched (e.g., using Radio Resource Control (RRC) connection signalling, or downlink control information (DCI) signalling) in dependence on changes in the traffic flow requirements.

[0121] However, a UE configured with different BWPs may lead to BWPs having different Time Division Duplex (TDD) DL-UL configurations. The presently described slot format signaling mechanisms may be extended to be associated with specific BWP types. The attributes of the BWPs may also be shared between gNB over the Xn interface and/or the F1 interface. [0122] For example, when a cell provided by a gNB comprises multiple BWPs, the parameter “BWP linkage” may, when provided, be used to express that the SBFD slot format applies for only a certain BWP of the cell (e.g. for the lnitial_BWP), while the remaining bandwidth of the cell is, for example, by default, DL transmissions only. [0123] For cases where one BWP of a cell is SBFD and other parts UL-only, the UL- only parts may be excluded as the impact of DL-to-UL interference from the SBFD part on the signalling of the UL-only part may be too high.

[0124] FIG. 6 illustrates an example slot configuration in which the carrier bandwidth is split into two BWPs, BWP#1 601 , and BWP#2602. In this example, BWP #1 comprises a SBFD format in which UL resources (including guard symbols) 603 are sandwiched between DL resources 604. BWP #2 602 comprises DL-only resources 605.

[0125]Table 3 and FIG. 7 illustrates another example of how SBFD frequency information may be determined.

[0126] In the existing Xn signaling, the reference resource block and the transmission bandwidth in number of RBs is shared by the IE NR Frequency Info and NR Transmission Bandwidth, respectively.

[0127] With this information, gNBs may indicate the uplink sub-band configuration on SBFD slots using at least one of the parameters illustrated in Table 3.

Table 3 Summary of parameters for Xn/F1 signaling of a single SBFD format

[0128]A given gNB may use at least some of the information indicated in Table 3 to derive the position of the UL sub-band.

[0129] This is illustrated with respect to the slot format(s) of FIG. 7. [0130] FIG. 7 illustrates a slot format comprising an uplink sub-band 702 sandwiched between downlink sub-bands 701 , 703. The gaps between the uplink sub-band 702 and the adjacent downlink sub-bands 701 , 703 correspond to respective guard bands between the uplink and downlink transmission resources.

[0131] FIG. 7 further indicates a point A that references a first resource, a point B that references a frequency location for an initial UL resource (e.g., point A plus an uplink sub-band offset), and a point C that references a frequency location for a final UL resource (e.g., point B plus an UL sub-band bandwidth). The UL sub-band bandwidth is represented by the double-ended arrow in FIG. 7. The total frequency width of the slot illustrated in FIG. 7 is labelled as the NR transmission bandwidth.

[0132] In this example of FIG. 7, there is indicated a starting position of the UL subband of a neighbour gNB. This starting position may be determined by calculating the denoted point B as the sum of Point A and an UL sub-band offset parameter that may be signalled (e.g., as per the information indicated in Table 3).

[0 33] Point A may be determined as a reference RB that is derived from the absolute radio-frequency channel number (ARFCN) information.

[0134] In one example, the UL sub-band offset can be set to 0 (or it is not exchanged). In this example, the starting frequency position of the UL sub-band is equal to Point A. This means that the UL sub-band is located in the lower edge of the carrier.

[0135] The last resource block (RB) within the UL sub-band is labelled as point C in FIG. 7. As mentioned above, point C may be determined as the sum of the frequency of point B and a number of UL sub-band PRBs for the UL. In the example in which point C equals the sum of Point A and the NR transmission bandwidth, then the UL sub-band is located at the upper edge of the carrier.

[0136] Further, the RBs dedicated to DL transmissions can be derived by combining the information of the guard bands with the UL sub-band location.

[0137] When the UL sub-band is located at the edge of the carrier, the gNB may interpret the “number of guard PRBs” parameter as a single set of PRBs. When the “number of guard PRBs” is not exchanged between gNBs, the receiving gNB considers it equal to 0. [0138] When the UL sub-band is located in the lower edge of the carrier, the start of the DL sub-band is given by the sum of point C and the “number of guard PRBs”, and the end of the DL sub-band is given by the sum of point A and the NR transmission bandwidth.

[0139] When the UL sub-band is located at the upper edge of the carrier, the start of the DL sub-band is given by point A and the end of the DL sub-band is given by the sum of Point B minus the “number of guard PRBs”.

[0140] When the UL sub-band is located at the center of the carrier (e.g., when the UL sub-band is sandwiched between DL sub-bands), a gNB may interpret the “number of guard PRBs” value signalled as the number of PRBs dedicated for guard band at each side of the UL sub-band.

[0141]As mentioned above, defining the UL sub-band in the middle of the carrier generates two DL sub-bands: The first DL sub-band of these two DL sub-bands starts in point A and ends in the frequency value of the sum of point B minus the indicated “number of guard PRBs”. The second DL sub-band of these two DL sub-bands starts at the frequency value of the sum of point C and the signalled “number of guard PRBs”, and ends in the frequency value of the sum of point A and the NR transmission bandwidth. This approach may be used regardless of whether or not the two DL subbands are equal in bandwidth or not.

[0142] The signalling of time information is now considered.

[0143] The time-series of the enhanced radio frame configuration may be captured in the Slot Configuration List contain (see above but with the enhancements that elements of that list can now also equal SBFD slot formats as per the new description in Table 1.

[0144] FIG. 8 illustrates an example of how the Slot Configuration List could be configured for the case where the radio frame configuration has a transmission periodicity of five slots.

[0145] In the example of FIG. 8, five consecutive transmission slots are indicated. These five consecutive transmission slots are respectively labelled Slot #0, Slot #1 , Slot #2, Slot #3, and Slot #4. Slot #0 is indicated as comprising only DL resources. Slot #1 comprises both UL and DL resources in a first SBFD format (SBFD_1). Slots #2 and #3 comprise both UL and DL resources in a second SBFD format (SBFD_2). Slot #4 comprises only uplink resources.

[0146] The parameters of Table 1 may be used to indicate the slot formats of each of these slots of FIG. 8.

[0147] It is also proposed to allow options in which, for some slots in the Slot Configuration List may comprise multiple slot format indications. For such cases, this means that the access node signals that the intended flexible radio frame configuration will dynamically select between those indicated slot formats. This may be useful for scenarios in which a hybrid of semi-static and dynamic flexible duplexing operation is deployed. In such an operation, one access node may decide to use fixed slot formats for slot numbers 0,1 ,2, and 4, while reserving the freedom to dynamically switch between SBFD and DL-only or UL-only for slot number 3 in dependence on the instantaneous traffic conditions.

[0148] The access node receiving the new intended flexible radio frame configuration may send back a message to indicate if the received configuration is acceptable to the receiving access node (e.g., from a cross link interference perspective), or whether some other configuration is recommended for use by the transmitting access node.

[0149] When the access node receiving the Intended flexible radio frame configuration prefers a different duplexing frame configuration, the receiving access node may respond by sending back a new Intended flexible radio frame configuration that it recommends the other node to use. This is illustrated in FIG. 9 for signaling over the Xn interface.

[0150] FIG. 9 illustrates signalling that may be performed between a first gNB 901 and a second gNB 902.

[0151] During 9001 , the first gNB decides on an enhanced radio frame configuration to use on signalling within at least one cell provided by the first gNB 901 . [0152] During 9002, the first gNB 901 signals the second gNB 902. This signalling may comprise an indication of the enhanced intended radio frame configuration. This signalling may comprise options for several new SBFD slots, potential power reductions, different slot formats per BWP, etc.

[0153] During 9003, the second gNB 902 determines to send a new proposal of an enhanced radio frame configuration to be used by the first gNB 901 instead of the signalled enhanced radio frame configuration of 9002.

[0154] During 9004, the second gNB 902 signals the first gNB 901 . This signalling may comprise an indication of the proposed new enhanced radio frame configuration to be used by the first gNB 901 instead of the signalled enhanced radio frame configuration of 9002. As discussed above, the first gNB 901 may use this information (and potentially a priority of the second gNB) to determine whether to adjust the indicated slot configuration to another slot configuration (e.g., to uplink only and/or downlink only), to adjust the power level(s) associated with any of the transmission opportunities scheduled in the slot, and/or to adjust the timing of the transmission opportunities.

[0155]As a minor variation to the above example of FIG. 9, during 9002, the first gNB

901 may provide a set (e.g., more than one) of enhanced intended radio frame configurations to the second gNB 902. Subsequently, during 9003, the second gNB

902 may determine which enhanced intended radio frame configuration of the provided set is preferred by the second gNB 902 for minimizing crosslink interference. The second gNB 902 may provide an indication of the preferred enhanced intended radio frame configuration to the first gNB 901 during 9004. Alternatively of additionally, during 9003, the second gNB may determine a relative priority for at least two of the enhanced intended radio frame configurations of the provided set and provide an indication of these relative priorities to the first gNB 901 during 9004.

[0156] For the gNB split architecture that comprises both centralized units and distributed units, FIG. 10 illustrates how the proposed signaling of enhanced intended radio frame configuration may be signalled from a CU to the DUs controlled by that CU in order to implement a simple form of centralized multi-cell coordination. In this example of FIG. 10, a CU may inform the cells being served by the different DUs which frame configuration to use, including potential SBFD formats.

[0157] FIG. 10 illustrates signalling that may be performed between a CU 1001 , a first DU 1002, and a second DU 1003. The signalling between CU 1001 and each of the first DU 1002 and the second DU 1003 may be performed over respective interfaces.

[0158] During 10001 , the CU 1001 decides on an enhanced radio frame configuration to use on signalling within at least one cell provided by the first DU 1002, and on an enhanced radio frame configuration to use on signalling within at least one cell provided by the second DU 1003.

[0159] During 10002, the CU 1001 signals the first DU 1002. This signalling may comprise an indication of the enhanced intended radio frame configuration. This signalling may comprise options for several new SBFD slots, potential power reductions, different slot formats per BWP, etc. to be used for at least one cell served by the first DU 1002.

[0160] During 10003, the CU 1001 signals the second DU 1003. This signalling may comprise an indication of the enhanced intended radio frame configuration. This signalling may comprise options for several new SBFD slots, potential power reductions, different slot formats per BWP, etc. to be used for at least one cell served by the second DU 1003. The configuration signalled to the first DU during 10002 may be different to the configuration signalled to the second DU during 10003.

[0161] FIGs. 11 and 12 illustrate operations that may be performed by apparatus illustrated in the above examples. It is therefore understood that at least one of the features mentioned below in connection with these FIGs. may find functional correspondence with at least one feature mentioned above. Further, the above examples may illustrate at least one example for implementing the presently described mechanisms of FIGs. 11 and 12.

[0162] FIG. 11 illustrates operations that may be performed by an apparatus. The apparatus may be comprised in an access node. Such an access node may be referred to as a second access node in connection with FIG. 12. [0163] During 1101 , the apparatus receives, from a first access node, signalling comprising a first slot configuration (e.g., a first SBFD slot configuration) comprising concurrent uplink and downlink transmission opportunities between the first access node and a user equipment served by the first access node, wherein the apparatus is comprised in a second access node. The first access node may be comprised in the apparatus of FIG. 12.

[0164] The apparatus may determine an interference mitigation mechanism to be deployed by the apparatus during a time slot based on the indicated first slot configuration, and cause the interference mitigation mechanism to be deployed.

[0165] The causing the interference mitigation mechanism to be performed may comprise performing at least one of: adjusting a power level to be used for an uplink and/or downlink transmission opportunity scheduled by the apparatus; adjusting a timing of an uplink and/or downlink transmission opportunity scheduled by the apparatus; signalling the first access node to request that the first access node adjusts a power level to be used for at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; signalling the first access node to request that the first access node adjusts a timing of at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; or signalling the first access node to request that the first access node abstains from scheduling an uplink and/or downlink transmission opportunity during the time slot.

[0166] The apparatus may receive, from the first access node, an indication that the first access node will schedule transmissions associated with a reduced power throughout a time duration, and prioritize uplink signalling and/or higher priority traffic between the second access node and a user equipment throughout the time duration based on the received indication. In this example, the apparatus may exploit an expected reduction in crosslink interference to transmit more important traffic. [0167] FIG. 12 illustrates operations that may be performed by an apparatus. The apparatus may be comprised in an access node. Such an access node may correspond to the first access node of FIG. 11 .

[0168] During 1201 , the apparatus transmits, to a second access node, signalling comprising a first slot configuration (e.g., a first SBFD configuration) comprising concurrent uplink and downlink transmission opportunities between the apparatus and a user equipment served by the apparatus, wherein the apparatus is comprised in a first access node.

[0169] The apparatus may receive, from the second access node, a request to perform at least one of the follow actions: adjust a power level to be used for at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during a time slot; adjust a timing of at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; or abstain from scheduling an uplink and/or downlink transmission opportunity during the time slot. The apparatus may determine whether to perform at least one of the requested actions. When the apparatus determines to perform at least one of the requested actions, the at least one requested action is performed by the apparatus. When the apparatus determines to not perform the at least one of the requested actions, the apparatus abstains from performing the at least one of the requested actions.

[0170]The signalling of any of FIGs. 11 and 12 may comprise an indication that the first access node will transmit during the indicated downlink transmission opportunities using a reduced transmission power relative to the first access node’s average transmission power. As this relates to the apparatus of FIG. 12, the apparatus may signal, to the second access node, an indication that the first access node will schedule transmissions associated with a reduced power throughout a time duration, and communicate with at least one user equipment using the reduced power throughout the time duration. [0171] The following described actions and/or features may be performed by the apparatus of any of FIGs. 11 and 12.

[0172] The signalling may comprise an indication of a first specific portion of a range of contiguous frequencies to which the indicated first slot configuration is to be applied. The first specific portion of the range of contiguous frequencies may correspond to a first bandwidth part. Stated different, the signalling may comprise an indication of a first bandwidth part to which at least part of the indicated first slot configuration is to be applied.

[0173] The signalling may comprise an indication that the first slot configuration further comprises: a second slot configuration, wherein the second slot configuration comprises one of: uplink only transmission opportunities, downlink only transmission opportunities, or uplink and downlink transmission opportunities; and an indication of a second specific portion of the range of contiguous frequencies (e.g., to a second bandwidth part) to which the indicated second slot configuration is to be applied. Stated differently, the signalling may comprise at least two (and potentially more than two) slot configurations with respective bandwidth part indications that indicate to which bandwidth part each slot configuration will be used for.

[0174] The signalling may comprise: an indication of a third slot configuration available for use by the first access node during a time slot, wherein the first slot configuration is also indicated as being available for use by the first access node during the time slot, where the third slot configuration comprises one of: uplink only transmission opportunities, downlink only transmission opportunities, or concurrent uplink and downlink transmission opportunities; and an indication that a slot configuration that will actually be used by the first access node during the time slot for transmissions between the first access node and the user equipment will be dynamically selected by the first access node based on network conditions between the first access node and the user equipment determined at a preconfigured time.

[0175] Stated differently, the signalling may indicate that the first access node is able to (and will) select between two or more slot configurations for use in a specified time duration. The first access node may (dynamically) select one of the two or more slot configurations based on current and/or predicated network conditions between the first access node and at least one UE to which the first access node will transmit during that specified time duration.

[0176]The signalling may comprise an indication that the uplink transmission opportunities for the first slot configuration, and/or the third slot configuration (where available) are located at a respective one of: a lower range of frequencies than a range of frequencies associated with the downlink transmission opportunities; between two ranges of frequencies associated with the downlink transmission opportunities; and a higher range of frequencies than a range of frequencies associated with the downlink transmission opportunities. The range of frequencies associated with the downlink transmission opportunities may comprise carrier frequencies.

[0177] The signalling may comprise an indication of where the uplink transmission opportunities for the first slot configuration are located by comprising an offset that represents a frequency offset from a reference resource.

[0178] The signalling may comprise: an indication of a frequency bandwidth size to be used for the downlink transmission opportunities, and an indication of at least one range of frequencies of a guard band (e.g., a size of resources to be used as a guard band between uplink and downlink transmission opportunities).

[0179] The signalling may comprise: an indication of a frequency bandwidth size to be used for the uplink transmission opportunities, and an indication of at least one range of frequencies of a guard band (e.g., a size of resources to be used as a guard band between uplink and downlink transmission opportunities).

[0180] The first access node may be one of a centralized unit or a distributed unit, and the second access node may be one of a centralized unit and a distributed unit.

[0181] The signalling may be signalled via one of: an Xn interface; and an F1 interface. [0182] The foregoing description has provided by way of non-limiting examples a full and informative description of some examples. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the claims. However, all such and similar modifications of the teachings will still fall within the scope of the claims.

[0183] In the above, different examples are described using, as an example of an access architecture to which the described techniques may be applied, a radio access architecture based on long term evolution advanced (LTE Advanced, LTE-A) or new radio (NR, 5G), without restricting the examples to such an architecture, however. The examples may also be applied to other kinds of communications networks having suitable means by adjusting parameters and procedures appropriately. Some examples of other options for suitable systems are the universal mobile telecommunications system (UMTS) radio access network (UTRAN), wireless local area network (WLAN or Wi-Fi), worldwide interoperability for microwave access (WiMAX), Bluetooth®, personal communications services (PCS), ZigBee®, wideband code division multiple access (WCDMA), systems using ultra-wideband (UWB) technology, sensor networks, mobile ad-hoc networks (MANETs) and Internet Protocol multimedia subsystems (IMS) or any combination thereof.

[0184] As provided herein, various aspects are described in the detailed description of examples and in the claims. In general, some examples may be implemented in hardware or special purpose circuits, software code, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software code which may be executed by a controller, microprocessor or other computing device, although examples are not limited thereto. While various examples may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software code, firmware code, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof. [0185] The examples may be implemented by computer software code stored in a memory and executable by at least one data processor of the involved entities or by hardware, or by a combination of software code and hardware.

[0186] The memory referred to herein may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. [0187] The (data) processors referred to herein may be of any type suitable to the local technical environment, and may comprise one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), FPGA, gate level circuits and processors based on multi core processor architecture, as non-limiting examples.

[0188] Further in this regard it should be noted that any procedures, e.g., as in FIG. 11 and/or FIG. 12, and/or otherwise described previously, may represent operations of a computer program being deployed by at least one processor comprised in an apparatus (where a computer program comprises instructions for causing an apparatus to perform at least one action, the instructions being represented as software code stored on at least one memory), or interconnected logic circuits, blocks and functions, or a combination of operations of a computer program being deployed by at least one processor comprised in an apparatus and logic circuits, blocks and functions. The software code may be stored on memory, such as physical media as memory chips, or memory blocks implemented within the processor, magnetic media (such as hard disk or floppy disks), and optical media (such as for example DVD and the data variants thereof, CD, and so forth).

[0189] The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), gate level circuits and processors based on multicore processor architecture, as nonlimiting examples.

[0190] Additionally or alternatively, some examples may be implemented using circuitry. The circuitry may be configured to perform one or more of the functions and/or method steps previously described. That circuitry may be provided in the base station and/or in the communications device and/or in a core network entity.

[0191]As used in this application, the term “circuitry” or “means” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analogue and/or digital circuitry);

(b) combinations of hardware circuits and software cade, such as:

(i) a combination of analogue and/or digital hardware circuit(s) with software/firmware code and

(ii) any portions of hardware processor(s) with software code (including digital signal processor(s)), software code, and memory(ies) that work together to cause an apparatus, such as the communications device or base station to perform the various functions previously described; and

(c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software code (e.g., firmware) for operation, but the software code may not be present when it is not needed for operation. [0192] 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 code. The term circuitry also covers, for example integrated device. [0193] Implementations of the disclosure may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

[0194] As used herein, “at least one of the following: <a list of two or more elements>” and “at least one of <a list of two or more elements>” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0195] The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0196] The scope of protection sought for various examples of the disclosure is set out by the independent claims. The 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 the disclosure.

[0197] The foregoing description has provided by way of non-limiting examples a full and informative description of example implementations of this disclosure. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of this disclosure will still fall within the scope of this invention as defined in the appended claims. Indeed, there is a further implementation comprising a combination of one or more implementations with any of the other implementations previously discussed.

Claims

1) An apparatus comprising means for: receiving, from a first access node, signalling comprising a first slot configuration comprising concurrent uplink and downlink transmission opportunities between the first access node and a user equipment served by the first access node, wherein the apparatus is comprised in a second access node.

2) An apparatus as claimed in claim 1 , further comprising means for: determining an interference mitigation mechanism to be deployed by the apparatus during a time slot based on the indicated first slot configuration; and causing the interference mitigation mechanism to be deployed.

3) An apparatus as claimed in claim 2, wherein the interference mitigation mechanism comprises at least one of: adjusting a power level to be used for an uplink and/or downlink transmission opportunity scheduled by the apparatus; adjusting a timing of an uplink and/or downlink transmission opportunity scheduled by the apparatus; signalling the first access node to request that the first access node adjusts a power level to be used for at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; signalling the first access node to request that the first access node adjusts a timing of at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; or signalling the first access node to request that the first access node abstains from scheduling an uplink and/or downlink transmission opportunity during the time slot. 4) An apparatus as claimed in any preceding claim, further comprising means for: receiving, from the first access node, an indication that the first access node will schedule transmissions associated with a reduced power throughout a time duration; and prioritizing uplink signalling and/or higher priority traffic between the second access node and a user equipment throughout the time duration based on the received indication.

5) An apparatus comprising means for: transmitting, to a second access node, signalling comprising a first slot configuration comprising concurrent uplink and downlink transmission opportunities between the apparatus and a user equipment served by the apparatus, wherein the apparatus is comprised in a first access node.

6) An apparatus as claimed in claim 5, further comprising means for: receiving, from the second access node, a request to perform at least one of the follow actions: adjust a power level to be used for at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during a time slot; adjust a timing of at least one of the uplink and/or downlink transmission opportunities scheduled by the first access node during the time slot; or abstain from scheduling an uplink and/or downlink transmission opportunity during the time slot; and determining whether to perform at least one of the requested action.

7) An apparatus as claimed in any preceding claim, wherein the signalling comprises an indication of a first specific portion of a range of contiguous frequencies to which at least part of the indicated first slot configuration is to be applied. 8) An apparatus as claimed in claim 7, wherein the signalling comprises: an indication that the first slot configuration further comprises a second slot configuration, wherein the second slot configuration comprises one of: uplink only transmission opportunities, downlink only transmission opportunities, or uplink and downlink transmission opportunities; and an indication of a second specific portion of the range of contiguous frequencies to which the indicated second slot configuration is to be applied.

9) An apparatus as claimed in any preceding claim, wherein the signalling comprises an indication that the first access node will transmit during the indicated downlink transmission opportunities using a reduced transmission power relative to the first access node’s average transmission power.

10)An apparatus as claimed in any preceding claim, wherein the signalling comprises: an indication of a third slot configuration available for use by the first access node during a time slot, wherein the first slot configuration is also indicated as being available for use by the first access node during the time slot, where the third slot configuration comprises one of: uplink only transmission opportunities, downlink only transmission opportunities, or concurrent uplink and downlink transmission opportunities; and an indication that a slot configuration that will actually be used by the first access node during the time slot for transmissions between the first access node and the user equipment will be dynamically selected by the first access node based on network conditions between the first access node and the user equipment determined at a preconfigured time. 11)An apparatus as claimed in any preceding claim, wherein the signalling comprises an indication that the uplink transmission opportunities for the first slot configuration are located at one of: a lower range of frequencies than a range of frequencies associated with the downlink transmission opportunities; between two ranges of frequencies associated with the downlink transmission opportunities; and a higher range of frequencies than a range of frequencies associated with the downlink transmission opportunities.

12) An apparatus as claimed in any of claims 1 to 10, wherein the signalling comprises an indication of where the uplink transmission opportunities for the first slot configuration are located by comprising an offset that represents a frequency offset from a reference resource.

13)An apparatus as claimed in claim 11 and/or claim 12, wherein the signalling comprises: an indication of a frequency bandwidth size to be used for the downlink transmission opportunities, and an indication of at least one range of frequencies of a guard band.

14) An apparatus as claimed in claim 12 and/or claim 13, wherein the signalling comprises: an indication of a frequency bandwidth size to be used for the uplink transmission opportunities, and an indication of at least one range of frequencies of a guard band.

15)An apparatus as claimed in any preceding claim, wherein the first access node is one of a centralized unit or a distributed unit, and the second access node is one of a centralized unit and a distributed unit. 16) An apparatus as claimed in any preceding claim, wherein the signalling is signalled via one of: an Xn interface; and an F1 interface.

17)A method for an apparatus, the method comprising: receiving, from a first access node, signalling comprising a first slot configuration comprising concurrent uplink and downlink transmission opportunities between the first access node and a user equipment served by the first access node, wherein the apparatus is comprised in a second access node.

18)A method for an apparatus, the method comprising: transmitting, to a second access node, signalling comprising a first slot configuration comprising concurrent uplink and downlink transmission opportunities between the apparatus and a user equipment served by the apparatus, wherein the apparatus is comprised in a first access node.

19)A computer program comprising instructions which, when executed by an apparatus, causes the apparatus to perform: receiving, from a first access node, signalling comprising a first slot configuration comprising concurrent uplink and downlink transmission opportunities between the first access node and a user equipment served by the first access node, wherein the apparatus is comprised in a second access node.

20)A computer program comprising instructions which, when executed by an apparatus, causes the apparatus to perform: transmitting, to a second access node, signalling comprising a first slot configuration comprising concurrent uplink and downlink transmission opportunities between the apparatus and a user equipment served by the apparatus, wherein the apparatus is comprised in a first access node.