WO2024167527A1

WO2024167527A1 - Fronthaul-based resource coordination

Info

Publication number: WO2024167527A1
Application number: PCT/US2023/062251
Authority: WO
Inventors: Navin Hathiramani
Original assignee: Nokia Solutions and Networks Oy; Nokia of America Corp
Current assignee: Nokia Solutions and Networks Oy; Nokia of America Corp
Priority date: 2023-02-09
Filing date: 2023-02-09
Publication date: 2024-08-15
Anticipated expiration: 2025-08-09
Also published as: EP4662956A1

Abstract

Disclosed is a method comprising receiving (601) first fronthaul data associated with a first radio access technology, the first fronthaul data comprising first user-plane data and first control-plane data, wherein the first control-plane data indicates a first set of radio resources intended for transmitting the first user-plane data over an air interface; determining (602), based on the first set of radio resources, a second set of radio resources intended for transmitting second user-plane data over the air interface, wherein the second user-plane data is associated with a second radio access technology; and transmitting (603), to a radio unit, at least second fronthaul data comprising the second user-plane data and second control-plane data, wherein the second control-plane data indicates the second set of radio resources intended for transmitting the second user-plane data over the air interface.

Description

FRONTHAUL-BASED RESOURCE COORDINATION

FIELD

The following example embodiments relate to wireless communication.

BACKGROUND

As new radio access technologies are emerging, there is a challenge in how to operate the new radio access technologies in parallel with existing radio access technologies.

BRIEF DESCRIPTION

The scope of protection sought for various example embodiments is set out by the independent claims. The example embodiments and features, if any, described in this specification that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various embodiments.

According to an aspect, there is provided an apparatus comprising at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive first fronthaul data associated with a first radio access technology, the first fronthaul data comprising first user-plane data and first control-plane data, wherein the first control-plane data indicates a first set of radio resources intended for transmitting the first user-plane data over an air interface; determine, based on the first set of radio resources, a second set of radio resources intended for transmitting second user-plane data over the air interface, wherein the second user-plane data is associated with a second radio access technology; and transmit, to a radio unit, at least second fronthaul data comprising the second user-plane data and second control-plane data, wherein the second control-plane data indicates the second set of radio resources intended for transmitting the second user-plane data over the air interface.

According to another aspect, there is provided an apparatus comprising: means for receiving first fronthaul data associated with a first radio

I access technology, the first fronthaul data comprising first user-plane data and first control-plane data, wherein the first control-plane data indicates a first set of radio resources intended for transmitting the first user-plane data over an air interface; means for determining, based on the first set of radio resources, a second set of radio resources intended for transmitting second user-plane data over the air interface, wherein the second user-plane data is associated with a second radio access technology; and means for transmitting, to a radio unit, at least second fronthaul data comprising the second user-plane data and second control-plane data, wherein the second control-plane data indicates the second set of radio resources intended for transmitting the second user-plane data over the air interface.

According to another aspect, there is provided a method comprising: receiving first fronthaul data associated with a first radio access technology, the first fronthaul data comprising first user-plane data and first control-plane data, wherein the first control-plane data indicates a first set of radio resources intended for transmitting the first user-plane data over an air interface; determining, based on the first set of radio resources, a second set of radio resources intended for transmitting second user-plane data over the air interface, wherein the second user-plane data is associated with a second radio access technology; and transmitting, to a radio unit, at least second fronthaul data comprising the second user-plane data and second control-plane data, wherein the second control-plane data indicates the second set of radio resources intended for transmitting the second user-plane data over the air interface.

According to another aspect, there is provided a computer program comprising instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: receiving first fronthaul data associated with a first radio access technology, the first fronthaul data comprising first user-plane data and first control-plane data, wherein the first control-plane data indicates a first set of radio resources intended for transmitting the first userplane data over an air interface; determining, based on the first set of radio resources, a second set of radio resources intended for transmitting second user- plane data over the air interface, wherein the second user-plane data is associated with a second radio access technology; and transmitting, to a radio unit, at least second fronthaul data comprising the second user-plane data and second controlplane data, wherein the second control-plane data indicates the second set of radio resources intended for transmitting the second user-plane data over the air interface.

According to another aspect, there is provided a computer readable medium comprising program instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: receiving first fronthaul data associated with a first radio access technology, the first fronthaul data comprising first user-plane data and first control-plane data, wherein the first control-plane data indicates a first set of radio resources intended for transmitting the first userplane data over an air interface; determining, based on the first set of radio resources, a second set of radio resources intended for transmitting second userplane data over the air interface, wherein the second user-plane data is associated with a second radio access technology; and transmitting, to a radio unit, at least second fronthaul data comprising the second user-plane data and second controlplane data, wherein the second control-plane data indicates the second set of radio resources intended for transmitting the second user-plane data over the air interface.

According to another aspect, there is provided a non-transitory computer readable medium comprising program instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: receiving first fronthaul data associated with a first radio access technology, the first fronthaul data comprising first user-plane data and first control-plane data, wherein the first control-plane data indicates a first set of radio resources intended for transmitting the first user-plane data over an air interface; determining, based on the first set of radio resources, a second set of radio resources intended for transmitting second user-plane data over the air interface, wherein the second user-plane data is associated with a second radio access technology; and transmitting, to a radio unit, at least second fronthaul data comprising the second user-plane data and second control-plane data, wherein the second control-plane data indicates the second set of radio resources intended for transmitting the second user-plane data over the air interface.

According to another aspect, there is provided a system comprising at least a first network node associated with a first radio access technology, a second network node associated with a second radio access technology, and a radio unit. The first network node is configured to: transmit, to the second network node or to the radio unit, first fronthaul data associated with the first radio access technology, the first fronthaul data comprising first user-plane data and first control-plane data, wherein the first control-plane data indicates a first set of radio resources intended for transmitting the first user-plane data over an air interface of the radio unit. The second network node is configured to: receive, from the first network node or the radio unit, the first fronthaul data; determine, based on the first set of radio resources, a second set of radio resources intended for transmitting second user-plane data over the air interface, wherein the second user-plane data is associated with the second radio access technology; and transmit, to the radio unit, at least second fronthaul data comprising the second user-plane data and second control-plane data, wherein the second control-plane data indicates the second set of radio resources intended for transmitting the second user-plane data over the air interface. The radio unit is configured to: receive, from the second network node, at least the second fronthaul data.

According to another aspect, there is provided a system comprising at least a first network node associated with a first radio access technology, a second network node associated with a second radio access technology, and a radio unit. The first network node comprises means for: transmitting, to the second network node or to the radio unit, first fronthaul data associated with the first radio access technology, the first fronthaul data comprising first user-plane data and first control-plane data, wherein the first control-plane data indicates a first set of radio resources intended for transmitting the first user-plane data over an air interface of the radio unit. The second network node comprises means for: receiving, from the first network node or the radio unit, the first fronthaul data; determining, based on the first set of radio resources, a second set of radio resources intended for transmitting second user-plane data over the air interface, wherein the second user-plane data is associated with the second radio access technology; and transmitting, to the radio unit, at least second fronthaul data comprising the second user-plane data and second control-plane data, wherein the second control-plane data indicates the second set of radio resources intended for transmitting the second user-plane data over the air interface. The radio unit comprises means for: receiving, from the second network node, at least the second fronthaul data.

LIST OF DRAWINGS

In the following, various example embodiments will be described in greater detail with reference to the accompanying drawings, in which

FIG. 1 illustrates an example of a cellular communication network;

FIG. 2A illustrates an example of a system;

FIG. 2B illustrates an example of a system;

FIG. 3A illustrates an example of a system;

FIG. 3B illustrates an example of a system;

FIG. 4 illustrates a signaling diagram;

FIG. 5 illustrates a signaling diagram;

FIG. 6 illustrates a flow chart;

FIG. 7 illustrates a flow chart;

FIG. 8 illustrates a flow chart;

FIG. 9 illustrates a flow chart; and

FIG. 10 illustrates an example of an apparatus.

DETAILED DESCRIPTION

The following embodiments are exemplifying. Although the specification may refer to "an”, "one”, or "some” embodiments) in several locations of the text, this does not necessarily mean that each reference is made to the same embodiments), or that a particular feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments. In the following, different example embodiments will be described using, as an example of an access architecture to which the example embodiments may be applied, a radio access architecture based on long term evolution advanced (LTE Advanced, LTE-A), new radio (NR, 5G), beyond 5G, or sixth generation (6G) without restricting the example embodiments to such an architecture, however. It is obvious for a person skilled in the art that the example embodiments 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 may be the universal mobile telecommunications system (UMTS) radio access network (UTRAN or E-UTRAN), long term evolution (LTE, substantially the same as E-UTRA), 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.

FIG. 1 depicts examples of simplified system architectures showing some elements and functional entities, all being logical units, whose implementation may differ from what is shown. The connections shown in FIG. 1 are logical connections; the actual physical connections may be different. It is apparent to a person skilled in the art that the system may also comprise other functions and structures than those shown in FIG. 1.

The example embodiments are not, however, restricted to the system given as an example but a person skilled in the art may apply the solution to other communication systems provided with necessary properties.

The example of FIG. 1 shows a part of an exemplifying radio access network.

FIG. 1 shows user devices 100 and 102 configured to be in a wireless connection on one or more communication channels in a radio cell with an access node (AN) 104, such as an evolved Node B (abbreviated as eNB or eNodeB) or a next generation Node B (abbreviated as gNB or gNodeB), providing the radio cell. The physical link from a user device to an access node may be called uplink (UL) or reverse link, and the physical link from the access node to the user device may be called downlink (DL) or forward link. A user device may also communicate directly with another user device via sidelink (SL) communication. It should be appreciated that access nodes or their functionalities may be implemented by using any node, host, server or access point etc. entity suitable for such a usage.

A communication system may comprise more than one access node, in which case the access nodes may also be configured to communicate with one another over links, wired or wireless, designed for the purpose. These links may be used for signaling purposes and also for routing data from one access node to another. The access node may be a computing device configured to control the radio resources of communication system it is coupled to. The access node may also be referred to as a base station, a base transceiver station (BTS), an access point or any other type of interfacing device including a relay station capable of operating in a wireless environment. The access node may include or be coupled to transceivers. From the transceivers of the access node, a connection may be provided to an antenna unit that establishes bi-directional radio links to user devices. The antenna unit may comprise a plurality of antennas or antenna elements. The access node may further be connected to a core network 110 (CN or next generation core NGC). Depending on the deployed technology, the counterpart that the access node may be connected to on the CN side may be a serving gateway (S-GW, routing and forwarding user data packets), packet data network gateway (P-GW) for providing connectivity of user devices to external packet data networks, user plane function (UPF), mobility management entity (MME), or an access and mobility management function (AMF), etc.

The user device illustrates one type of an apparatus to which resources on the air interface may be allocated and assigned, and thus any feature described herein with a user device may be implemented with a corresponding apparatus, such as a relay node.

An example of such a relay node may be a layer 3 relay (self-backhauling relay) towards the access node. The self-backhauling relay node may also be called an integrated access and backhaul (IAB) node. The IAB node may comprise two logical parts: a mobile termination (MT) part, which takes care of the backhaul link(s) (i.e., link(s) between IAB node and a donor node, also known as a parent node) and a distributed unit (DU) part, which takes care of the access link(s), i.e., child link(s) between the IAB node and user device(s), and/or between the IAB node and other IAB nodes (multi -hop scenario).

Another example of such a relay node may be a layer 1 relay called a repeater. The repeater may amplify a signal received from an access node and forward it to a user device, and/or amplify a signal received from the user device and forward it to the access node.

The user device may also be called a subscriber unit, mobile station, remote terminal, access terminal, user terminal, terminal device, or user equipment (UE) just to mention but a few names or apparatuses. The user device may refer to a portable computing device that includes wireless mobile communication devices operating with or without a subscriber identification module (SIM), including, but not limited to, the following types of devices: a mobile station (mobile phone), smartphone, personal digital assistant (PDA), handset, device using a wireless modem (alarm or measurement device, etc.), laptop and/or touch screen computer, tablet, game console, notebook, multimedia device, reduced capability (RedCap) device, wireless sensor device, or any device integrated in a vehicle.

It should be appreciated that a user device may also be a nearly exclusive uplink-only device, of which an example may be a camera or video camera loading images or video clips to a network. A user device may also be a device having capability to operate in Internet of Things (loT) network which is a scenario in which objects may be provided with the ability to transfer data over a network without requiring human-to-human or human-to-computer interaction. The user device may also utilize cloud. In some applications, a user device may comprise a small portable or wearable device with radio parts (such as a watch, earphones or eyeglasses) and the computation may be carried out in the cloud or in another user device. The user device (or in some example embodiments a layer 3 relay node) may be configured to perform one or more of user equipment functionalities.

Various techniques described herein may also be applied to a cyberphysical system (CPS) (a system of collaborating computational elements controlling physical entities). CPS may enable the implementation and exploitation of massive amounts of interconnected ICT devices (sensors, actuators, processors microcontrollers, etc.) embedded in physical objects at different locations. Mobile cyber physical systems, in which the physical system in question may have inherent mobility, are a subcategory of cyber-physical systems. Examples of mobile physical systems include mobile robotics and electronics transported by humans or animals.

Additionally, although the apparatuses have been depicted as single entities, different units, processors and/or memory units (not all shown in FIG. 1) may be implemented.

5G enables using multiple input - multiple output (MIMO) antennas, many more base stations or nodes than the LTE (a so-called small cell concept), including macro sites operating in co-operation with smaller stations and employing a variety of radio technologies depending on service needs, use cases and/or spectrum available. 5G mobile communications may support a wide range of use cases and related applications including video streaming, augmented reality, different ways of data sharing and various forms of machine type applications (such as (massive) machine-type communications (mMTC), including vehicular safety, different sensors and real-time control. 5G may have multiple radio interfaces, namely below 6GHz, cmWave and mmWave, and also being integrable with existing legacy radio access technologies, such as the LTE. Integration with the LTE may be implemented, for example, as a system, where macro coverage may be provided by the LTE, and 5G radio interface access may come from small cells by aggregation to the LTE. In other words, 5G may support both inter-RAT operability (such as LTE-5G) and inter-RI operability (inter-radio interface operability, such as below 6GHz - cmWave - mmWave). One of the concepts considered to be used in 5G networks may be network slicing, in which multiple independent and dedicated virtual sub-networks (network instances) may be created within the substantially same infrastructure to run services that have different requirements on latency, reliability, throughput and mobility.

The current architecture in LTE networks may be fully distributed in the radio and fully centralized in the core network. The low latency applications and services in 5G may need to bring the content close to the radio which leads to local break out and multi-access edge computing (MEC). 5G may enable analytics and knowledge generation to occur at the source of the data. This approach may need leveraging resources that may not be continuously connected to a network such as laptops, smartphones, tablets and sensors. MEC may provide a distributed computing environment for application and service hosting. It may also have the ability to store and process content in close proximity to cellular subscribers for faster response time. Edge computing may cover a wide range of technologies such as wireless sensor networks, mobile data acquisition, mobile signature analysis, cooperative distributed peer-to-peer ad hoc networking and processing also classifiable as local cloud/fog computing and grid/mesh computing, dew computing, mobile edge computing, cloudlet, distributed data storage and retrieval, autonomic self-healing networks, remote cloud services, augmented and virtual reality, data caching, Internet of Things (massive connectivity and/or latency critical), critical communications (autonomous vehicles, traffic safety, realtime analytics, time-critical control, healthcare applications).

The communication system may also be able to communicate with one or more other networks 113, such as a public switched telephone network or the Internet, or utilize services provided by them. The communication network may also be able to support the usage of cloud services, for example at least part of core network operations may be carried out as a cloud service (this is depicted in FIG. 1 by "cloud” 114). The communication system may also comprise a central control entity, or the like, providing facilities for networks of different operators to cooperate for example in spectrum sharing.

An access node may also be split into: a radio unit (RU) comprising a radio transceiver (TRX), i.e., a transmitter (Tx) and a receiver (Rx); one or more distributed units (DUs) 105 that may be used for the so-called Layer 1 (LI) processing and real-time Layer 2 (L2) processing; and a central unit (CU) 108 (also known as a centralized unit) that may be used for non-real-time L2 and Layer 3 (L3) processing. The CU 108 may be connected to the one or more DUs 105 for example via an Fl interface. Such a split may enable the centralization of CUs relative to the cell sites and DUs, whereas DUs may be more distributed and may even remain at cell sites. The CU and DU together may also be referred to as baseband or a baseband unit (BBU). The CU and DU may also be comprised in a radio access point (RAP).

The CU 108 may be defined as a logical node hosting higher layer protocols, such as radio resource control (RRC), service data adaptation protocol (SDAP) and/or packet data convergence protocol (PDCP), of the access node. The DU 105 maybe defined as a logical node hosting radio link control (RLC), medium access control (MAC) and/or physical (PHY) layers of the access node. The operation of the DU may be at least partly controlled by the CU. The CU may comprise a control plane (CU-CP), which may be defined as a logical node hosting the RRC and the control plane part of the PDCP protocol of the CU for the access node. The CU may further comprise a user plane (CU-UP), which may be defined as a logical node hosting the user plane part of the PDCP protocol and the SDAP protocol of the CU for the access node.

Cloud computing platforms may also be used to run the CU 108 and/or DU 105. The CU may run in a cloud computing platform, which may be referred to as a virtualized CU (vCU). In addition to the vCU, there may also be a virtualized DU (vDU) running in a cloud computing platform. Furthermore, there may also be a combination, where the DU may use so-called bare metal solutions, for example application-specific integrated circuit (ASIC) or customer-specific standard product (CSSP) system-on-a-chip (SoC) solutions. It should also be understood that the distribution of functions between the above-mentioned access node units, or different core network operations and access node operations, may differ.

Edge cloud may be brought into radio access network (RAN) by utilizing network function virtualization (NFV) and software defined networking (SDN). Using edge cloud may mean access node operations to be carried out, at least partly, in a server, host or node operationally coupled to a remote radio head (RRH) or a radio unit (RU), or an access node comprising radio parts. It is also possible that node operations may be distributed among a plurality of servers, nodes or hosts. Application of cloudRAN architecture enables RAN real-time functions being carried out at the RAN side (e.g., in a DU 105) and non-real-time functions being carried out in a centralized manner (e.g., in a CU 108).

It should also be understood that the distribution of functions between core network operations and access node operations may differ from that of the LTE or even be non-existent. Some other technology advancements that may be used include big data and all-IP, which may change the way networks are being constructed and managed. 5G (or new radio, NR) networks may be designed to support multiple hierarchies, where MEC servers may be placed between the core and the access node. It should be appreciated that MEC may be applied in 4G networks as well.

5G may also utilize non-terrestrial communication, for example satellite communication, to enhance or complement the coverage of 5G service, for example by providing backhauling. Possible use cases may be providing service continuity for machine-to-machine (M2M) or Internet of Things (loT) devices or for passengers on board of vehicles, or ensuring service availability for critical communications, and future railway/maritime/aeronautical communications. Satellite communication may utilize geostationary earth orbit (GEO) satellite systems, but also low earth orbit (LEO) satellite systems, in particular megaconstellations (systems in which hundreds of (nano) satellites are deployed). A given satellite 106 in the mega-constellation may cover several satellite-enabled network entities that create on-ground cells. The on-ground cells may be created through an on-ground relay node or by an access node 104 located on-ground or in a satellite.

6G networks are expected to adopt flexible decentralized and/or distributed computing systems and architecture and ubiquitous computing, with local spectrum licensing, spectrum sharing, infrastructure sharing, and intelligent automated management underpinned by mobile edge computing, artificial intelligence, short-packet communication and blockchain technologies. Key features of 6G may include intelligent connected management and control functions, programmability, integrated sensing and communication, reduction of energy footprint, trustworthy infrastructure, scalability and affordability. In addition to these, 6G is also targeting new use cases covering the integration of localization and sensing capabilities into system definition to unifying user experience across physical and digital worlds.

It is obvious for a person skilled in the art that the depicted system is only an example of a part of a radio access system and in practice, the system may comprise a plurality of access nodes, the user device may have access to a plurality of radio cells and the system may also comprise other apparatuses, such as physical layer relay nodes or other network elements, etc. At least one of the access nodes may be a Home eNodeB or a Home gNodeB.

Additionally, in a geographical area of a radio communication system, a plurality of different kinds of radio cells as well as a plurality of radio cells may be provided. Radio cells may be macro cells (or umbrella cells) which may be large cells having a diameter of up to tens of kilometers, or smaller cells such as micro-, femto- or picocells. The access node(s) of FIG. 1 may provide any kind of these cells. A cellular radio system may be implemented as a multilayer network including several kinds of radio cells. In multilayer networks, one access node may provide one kind of a radio cell or radio cells, and thus a plurality of access nodes may be needed to provide such a network structure.

For fulfilling the need for improving the deployment and performance of communication systems, the concept of "plug-and-play” access nodes may be introduced. A network which may be able to use "plug-and-play” access nodes, may include, in addition to Home eNodeBs or Home gNodeBs, a Home Node B gateway, or HNB-GW (not shown in FIG. 1). An HNB-GW, which may be installed within an operator’s network, may aggregate traffic from a large number of Home eNodeBs or Home gNodeBs back to a core network.

In 3GPP Release 15, dynamic spectrum sharing (DSS) has been introduced as a framework to enable spectrum migration from one radio access technology to another (namely, from 4G to 5G). DSS allows for progressive resource (frequency) dedication to 5G NR, as NR UE penetration increases. With 4G-5G DSS, the 5G carrier can be deployed on top of an LTE carrier, allowing to support the LTE traffic while providing 5G coverage, even if the traffic demand for 5G is not yet there. In other words, DSS enables 5G and LTE to share the same carrier.

Operators may deploy 4G-5G DSS initially on low frequency bands to be able to claim extended 5G coverage. When NR UE penetration is low, it means that the majority of users are employing LTE UEs, and hence activation of 5G on cells should introduce minimum overheads. As NR UE penetration rate increase, more capacity will be needed for them, and hence an efficient sharing mechanism is needed for 4G-5G sharing in these low bands. These low bands may be targeted as fallback bands for UEs due to coverage challenges in other bands, and most operators may have limited low band spectrum and not have enough to have separate resources for LTE and NR, hence the introduction of DSS.

5G transmissions may avoid the LTE physical downlink control channel (PDCCH) and share the physical downlink shared channel (PDSCH) through time/frequency multiplexing. Furthermore, 5G transmissions may avoid the LTE cell-specific reference signal (CRS) by puncturing the 5G PDSCH resource elements that overlap with the LTE CRS in time and frequency.

Further down the road, DSS may be used as a sunset technology allowing to keep a low-band (best coverage) LTE carrier to provide the same LTE coverage as before, even with very little LTE traffic, while allowing that carrier to also provide the NR coverage and capacity.

With the introduction of 6G, operators are expecting a 5G-6G DSS solution that addresses many, if not all, of the pitfalls experienced with 4G-5G DSS. For 6G, it is expected that DSS will not only be targeted for low bands, such as frequency-division duplexing (FDD) bands, but also for mid-bands, such as timedivision duplexing (TDD) bands, and possibly even millimeter wave (mmWave).

In some cases, it may be beneficial to enable inter-vendor DSS deployments. For example, a first vendor may supply baseband processing for a first RAT (e.g., 5G), and a second vendor may supply baseband processing for a second RAT (e.g., 6G), wherein both RATs may employ the same radio unit (RU), which may be supplied by a third vendor.

To enable DSS efficiently, the scarce radio resources should be properly shared between the legacy RAT and the newly introduced RAT (e.g., between 4G and 5G, or between 5G and 6G).

FIG. 2A illustrates an example of an X2-based 4G-5G DSS RAN architecture comprising a 4G baseband unit (BBU) 201, a 5G CU 202, a 5G DU 203, and an RU 204. The communication between the 4G BBU 201 and 5G CU 202 may be performed via an X2 interface. However, the X2 interface may be inappropriate for the quick scheduling decisions needed between legacy and new RAT schedulers. The X2 interface over the stream control transmission protocol (SCTP) was not designed for this purpose and may further incur into Fl delays, when considering that a CU-DU split base station architecture may be employed for 5G (or even 4G).

FIG. 2B illustrates an example of a proprietary interface based DSS RAN architecture comprising a 4G BBU 201, a 5G CU 202, a 5G DU 203, and an RU 204. Currently, there may be single-vendor solutions for DSS, wherein the interface between the 4G BBU 201 and the 5G DU 203 (or 5G BBU) may be a high-speed proprietary interface between the schedulers. Standardizing this proprietary interface may be cumbersome due to very diverse scheduler implementations and due to the potential additional overheads that may be incurred in ensuring reliable communication between the schedulers. It may be desirable to minimize the number of new interfaces specified to leverage implementations, although an intervendor DSS solution may be required for 5G-6G DSS.

The open radio access network (0-RAN) is a global, industry-led initiative aimed at transforming the architecture and governance of radio access networks to promote greater innovation, competition, and open collaboration in the development of 5G and future wireless networks. The goal of 0-RAN is to create an open, multi-vendor RAN architecture that leverages standard interfaces, open software, and a highly automated network management and orchestration framework. In other words, O-RAN aims to promote greater interoperability, flexibility, and cost-effectiveness in the deployment and operation of 5G and future networks.

One of the main issues tackled by O-RAN was specifying open fronthaul specifications to enable interworking between radio units and baseband units of different vendors. The O-RAN fronthaul specifications specify the frame format for the control plane (C-plane) and user plane (U -plane) frames, which are exchanged between the radio unit and the baseband unit. From the C -plane frame formats sent by a BBU to an RU, one may observe the usage of the radio resources that the BBU intends to make for a given slot.

The fronthaul interface is the communication link between the radio unit and the baseband unit. Fronthaul data refers to the data that is transported over the fronthaul interface. This data may be processed and transmitted in realtime, and it may need to meet strict latency, bandwidth, and reliability requirements in order to support high-quality wireless services. Fronthaul data enables the delivery of voice, data, and multimedia services over wireless networks.

The ethernet common public radio interface (eCPRI) is standardized in O-RAN for fronthaul connectivity between base stations and their radio units, in 5G and other cellular networks. eCPRI provides a unified interface for transporting radio signals between the baseband unit and the radio unit, using ethernet technology. The goal of eCPRI is to simplify and standardize the fronthaul interface, allowing for more flexible deployment of 5G networks. It also provides a high- bandwidth, low-latency communication path.

Some example embodiments enable DSS scheduling coordination between cells of different RATs, such as 5G and 6G DSS cells. In some example embodiments, the eCPRI O-RAN interface may be reused to enable support for DSS coordination, and thus there is no need for specifying a new interface. This may have just some minor impacts on the 5G cell, such as support for some semi-static information exchange via Xn interface, support of protected resources information on the fronthaul, and configuring a group common physical downlink control channel (GC-PDCCH) resource for the 6G cell. No changes may be needed for 5G UEs, i.e., legacy 5G UEs can continue to use 5G-6G DSS cells.

Some example embodiments are described below using principles and terminology of 5G and 6G technology without limiting the example embodiments to 5G and 6G communication systems, however. For example, some example embodiments may also be applied to 4G and 5G communication systems.

In an example embodiment, a network node controlling a 6G DSS cell may receive or sniff and process the 5G DSS fronthaul data (at least the C-plane and U -plane data). Herein sniffing refers to receiving the data packets that are meant to be transmitted to the RU, and then possibly processing them to modify the contents. Based on the resource usage determined from the 5G fronthaul C-plane frames, the possible 6G resources for DSS scheduling may be determined. The network node controlling the 6G cell may puncture the 5G or 6G resources depending on which RAT is prioritized. A network node controlling the 5G cell may indicate, via the fronthaul C-plane frame structure, high-priority resources (protected resources), which should not be punctured. The network node controlling the 6G cell may transmit interrupted transmission information to 5G UEs of the 5G DSS cell, when the puncturing was performed for the 5G cell’s transmission. An interrupted transmission refers to a scenario, where a transmission is disrupted or stopped, for example due to the puncturing of the 5G resources.

A minimum set of resources to enable, for example, basic 6G broadcast signals to be sent may be reserved for 6G via 5G-6G coordination over an interface such as the Xn interface. These broadcast signals, such as the 6G synchronization signal block (SSB), 6G paging, and/or 6G physical downlink control channel (PDCCH), may be semi-static in nature, and hence the Xn type of interface can be employed for this coordination, while the more dynamic sharing of resources is performed as described above.

To enable the 6G DSS cell to transmit an interrupted transmission GC- PDCCH to the 5G DSS cell’s UEs, the 5G DSS cell may enable a separate control resource set (CORESET) for this with its associated Type 3 search space and configure the UEs with it. The configuration information along with the interruption radio network temporary identifier (INT-RNTI) may also be shared with the 6G DSS cell, which may be done for example via an Xn type of interface, since it is not latency-sensitive. Transmission of the interrupted transmission information from the 6G cell avoids the need for a high-speed and reliable interface in the 6G BBU towards the 5G BBU.

FIG. 3A and FIG. 3B illustrate some examples of possible RAN architectures, to which some example embodiments may be applied to. However, it should be noted that other architectures than those illustrated in FIG. 3A and FIG. 3B may also be possible. For example, some further 6G LI functionality could be performed by the RU for relaxation of processing times. Furthermore, the examples are depicted from a DL point of view, and hence the UL data flow of the fronthaul may follow the DL or be independent. It should also be noted that the architecture in FIG. 3B may be supported by most RUs, since most of them support RU chaining capabilities.

FIG. 3A illustrates an example of a 5G-6G DSS RAN architecture comprising a 5G CU 301, a 5G DU 302, a 6G CU 303, a 6G DU 304, and an RU 305. In this example, the RU 305 mirrors the 5G fronthaul data (e.g., eCPRI data) received from the 5G DU 302 to the 6G DU 304. The 6G DU 304 then provides the aggregated 5G and 6G fronthaul data to the RU 305.

FIG. 3B illustrates another example of a 5G-6G DSS RAN architecture comprising a 5G CU 301, a 5G DU 302, a 6G CU 303, a 6G DU 304, and an RU 305. In this example, the 6G DU 304 acts as a fronthaul gateway for the 5G DU 302.

The 5G CU 301 and the 5G DU 302 may also be collectively referred to as a 5G BBU. The 6G CU 303 and the 6G DU 304 may also be collectively referred to as a 6G BBU. Although one DU per CU is shown in FIG. 3A and FIG. 3B, it should be noted that a given CU may also control more than one DU, in which case the CU and the DUs together may be collectively referred to as a BBU.

The 6G BBU (or some other component within it) may receive the 5G eCPRI data, and the 6G BBU may then quickly perform its processing and forward the final control and user plane information to the RU for transmission within the allowed timing budgets. This scheme may be applied to resource (frequency, spatial and time) sharing for user data transmission. The resources needed for the control channel of 6G may be communicated to the 5G BBU for example via Xn (or similar interface). Additionally, the 5G BBU may also provide the 6G BBU with information on its common control channels and possibly on configuration of a CORESET and search space for the interrupted transmission indication.

Some example embodiments may be applied to, for example, DSS for frequency range one (FR1) or frequency range two (FR2).

FIG. 4 illustrates a signaling diagram according to an example embodiment. This signaling diagram may correspond to, for example, the architecture illustrated in FIG. 3B, where the 6G BBU acts as a fronthaul gateway for the 5G BBU. Herein the 5G BBU may also be referred to as a first network node, and the 6G BBU may also be referred to as a second network node.

Referring to FIG. 4, in block 401, the 6G BBU pre-schedules multiple sets of radio resources for transmitting data to 6G UEs. Herein the pre-scheduling means that the 6G scheduler decides which UE(s) it needs to schedule, the priority of the data of these UE(s), the coding rate and radio resources required for a given UE.

Herein the radio resources may refer to, for example, at least one of: time resources, frequency resources, and/or spatial resources. The time resources may refer to the time slots or symbols allocated for data transmission, which determine when data can be transmitted. The frequency resources may refer to the range of frequencies that are used to transmit data over the air interface. The spatial resources may refer to beams. A beam can be used to focus radio waves in a specific direction. Beams can be formed using multiple antennas, and they can be directed towards specific UEs, in order to provide reliable wireless connectivity. For example, by forming multiple beams in different directions, the network can provide connectivity to multiple UEs simultaneously.

The 6G scheduler may not be able finalize its scheduling, for example physical mapping of physical resource blocks (PRBs) or physical downlink control channel (PDCCH) allocations, until it receives the 5G fronthaul data, which includes what the 5G scheduler intends to transmit over the air interface. To maximize scheduling opportunities with minimal impact to 5G, in the pre-scheduling phase, the 6G scheduler may pre-schedule one or more UEs (different or same UEs) for different beams or time and frequency resources. This way, if a certain resource that the 6G scheduler intended to use is indicated as used by the 5G scheduler, it can fall back to other pre-scheduled resource(s). This scheme would imply additional pre-scheduling efforts (computations), but when the number of 6G UEs is low, this should be possible without exceeding established processing time delays.

Herein 5G may also be referred to as a first radio access technology, and 6G may also be referred to as a second radio access technology.

In block 402, the 6G BBU receives the 5G fronthaul data from the 5G BBU. The 5G fronthaul data may comprise, for example, 5G control-plane data and 5G user-plane data. The 5G control-plane data indicates a first set of radio resources intended for transmitting the 5G user-plane data over the air interface. The 5G BBU may also indicate, for example in the 5G C-plane data, one or more protected radio resources that should not be punctured in the first set of radio resources.

Herein the 5G fronthaul data may also be referred to as first fronthaul data. The 5G control-plane data may also be referred to as first control-plane data. The 5G user-plane data may also be referred to as first user-plane data.

In block 403, the 6G BBU processes the 5G fronthaul data and determines, based on the first set of radio resources (5G resources), a second set of radio resources (6G resources) intended for transmitting 6G user-plane data over the air interface. For example, the second set of radio resources maybe determined from the pre-scheduled multiple sets of resources by selecting a resource set that has the lowest amount of overlapping resources with the first set of radio resources.

In block 404, the 6G BBU determines, based on the first set of radio resources (i.e., the resources used by the 5G BBU), whether to perform puncturing for at least one of the first set of radio resources or the second set of radio resources. Puncturing means poking holes in one or more radio resources associated with one RAT, and possibly transmitting data or reference symbols associated with the other RAT over the holes.

In other words, the 6G BBU determines whether puncturing is needed. Puncturing may be needed, if there are one or more overlapping radio resources between the first set of radio resources and the second set of radio resources (i.e., if there are one or more resources that are used by both sets).

For example, if 6G has priority over 5G, then the 6G scheduler may puncture one or more 5G resources in the first set of radio resources to overwrite 5G data with its 6G C-plane and U-plane information. If the 6G BBU punctures the 5G resource(s), then it may modify the 5G C-plane and U-plane data accordingly for the fronthaul, and the 6G BBU may also inform the 5G UEs of the interrupted transmission with an interrupted transmission indication.

If puncturing is needed and the 5G BBU has indicated over the fronthaul (e.g., in the 5G C-plane data) that there are one or more protected radio resources in the first set of radio resources that should not be punctured, then the 6G BBU may puncture around the one or more protected resources (i.e., puncture one or more radio resources other than the one or more protected resources) to enable the transmission of the 6G data.

As another example, if 5G has priority over 6G, then the 6G scheduler may puncture one or more of the pre-scheduled 6G resources in the second set of radio resources to overwrite 6G data with 5G C-plane and U-plane information.

It may be up to the configuration between the 5G BBU and the 6G BBU (e.g., via Xn) whether the 5G transmission should be prioritized over the 6G transmission, or vice versa. For example, no puncturing may be allowed by 6G, or 6G transmissions may have a higher priority (i.e., the 6G BBU may puncture 5G resources as long as they are not protected).

Furthermore, it may also be possible to have more of a hybrid solution, where the 5G BBU indicates, in the 5G C-plane data, a priority order of the first set of radio resources (5G resources) relative to the second set of radio resources (6G resources), and the 6G BBU may then perform the puncturing according to the priority order, i.e., puncture lower-priority resources but not higher-priority resources.

On the other hand, puncturing may not be needed for an empty frame, or if there are no overlapping resources between the first set of radio resources and the second set of radio resources. For example, puncturing may not be needed, if a different beam is pre-scheduled for 6G compared to 5G. If puncturing is not needed, then the 6G BBU may aggregate its C-plane and U-plane data into the eCPRI frame and forward it for transmission to the RU. This could be, for example, the scenario where the 5G BBU and 6G BBU have decided to schedule different beams with minimum cross layer interference.

In block 405, the 6G BBU transmits the 6G fronthaul data and the 5G fronthaul data (the original 5G fronthaul data or the possibly modified 5G fronthaul data) to the radio unit. The 6G fronthaul data comprises the 6G user-plane data and 6G control-plane data, wherein the 6G control-plane data indicates the second set of radio resources intended for transmitting the 6G user-plane data over the air interface.

The 6G fronthaul data may also be referred to as second fronthaul data herein. The 6G user-plane data may also be referred to as second user-plane data herein. The 6G control-plane data may also be referred to as second control-plane data herein.

In block 406, the radio unit transmits, over the air interface, the 6G userplane data to one or more 6G UEs based on the 6G control-plane data. Furthermore, the radio unit transmits, over the air interface, the 5G user-plane data to one or more 5G UEs based on the 5G control-plane data.

In block 407, the 6G BBU may transmit, to the radio unit, an interrupted transmission indication for one or more 5G UEs, if puncturing was performed for the 5G resources.

If 5G resources were punctured, it may be beneficial to inform the 5G UEs about this fact. The 6G BBU may do this, if the 5G BBU provides the configuration for the GC-PDCCH for interrupted transmission to the 6G BBU for example via the Xn interface. Furthermore, if 6G LI compatibility allows for it, the CORESET and search space defined for the interrupted transmission indication for the one or more 5G UEs may also be shared with the 6G UEs. In this case, 5G and 6G cells may agree on the split of INT -RNTI values, but a single set of resources may be shared for this indication.

In block 408, the radio unit may transmit the interrupted transmission indication to the one or more 5G UEs over the air interface. For example, the interrupted transmission indication may be transmitted to the one or more 5G UEs on the GC-PDCCH monitored by the one or more 5G UEs based on the CORESET. The air interface refers to the wireless channel that is used for transmitting and receiving signals between the RU and UEs.

The interrupted transmission indication informs a given 5G UE about the interruption in the transmission of data. Based on the interrupted transmission indication, the UE can adjust its transmission behavior, such as retransmitting data or searching for a new cell to continue the transmission.

FIG. 5 illustrates a signaling diagram according to an example embodiment. This signaling diagram may correspond to, for example, the architecture illustrated in FIG. 3 A.

Referringto FIG. 5, in block 501, the 6G BBU pre-schedules multiple sets of radio resources for transmitting data to 6G UEs. Herein the pre-scheduling means that the 6G scheduler decides which UE(s) it needs to schedule, the priority of the data of these UE(s), the coding rate and radio resources required for a given UE.

The 6G scheduler may not be able finalize its scheduling, for example physical mapping of physical resource blocks (PRBs) or physical downlink control channel (PDCCH) allocations, until it receives the 5 G fronthaul data, which includes what the 5G scheduler intends to transmit over the air interface. To maximize scheduling opportunities with minimal impact to 5G, in the pre-scheduling phase, the 6G scheduler may pre-schedule one or more UEs (different or same UEs) for different beams or time and frequency resources. This way, if a certain resource that the 6G scheduler intended to use is indicated as used by the 5G scheduler, it can fall back to other pre-scheduled resource(s). This scheme would imply additional pre-scheduling efforts (computations), but when the number of 6G UEs is low, this should be possible without exceeding established processing time delays.

In block 502, the 5G BBU transmits the 5G fronthaul data to the radio unit.

In block 503, the 6G BBU receives the 5G fronthaul data from the radio unit. The 5G fronthaul data may comprise, for example, 5G control-plane data and 5G user-plane data. The 5G control-plane data indicates a first set of radio resources intended for transmitting the 5G user-plane data over the air interface. The 5G BBU may also indicate, for example in the 5G control-plane data, one or more protected radio resources that should not be punctured in the first set of radio resources.

In block 504, the 6G BBU processes the 5G fronthaul data and determines, based on the first set of radio resources (5G resources), a second set of radio resources (6G resources) intended for transmitting 6G user-plane data over the air interface. For example, the second set of radio resources maybe determined from the pre-scheduled multiple sets of resources by selecting a resource set that has the lowest amount of overlapping resources with the first set of radio resources.

The 6G user-plane data may also be referred to as second user-plane data herein.

In block 505, the 6G BBU determines, based on the first set of radio resources (i.e., the resources used by the 5G BBU), whether to perform puncturing for at least one of the first set of radio resources or the second set of radio resources. In other words, the 6G BBU determines whether puncturing is needed. Puncturing may be needed, if there are one or more overlapping radio resources between the first set of radio resources and the second set of radio resources (i.e., if there are one or more resources that are used by both sets).

For example, if 6G has priority over 5G, then the 6G scheduler may puncture one or more 5G resources in the first set of radio resources to overwrite 5G data with its 6G C-plane and U-plane information. If the 6G BBU punctures the 5G resource(s), then it may modify the 5G C-plane and U-plane data accordingly for the fronthaul, and the 6G BBU may also inform the 5G UEs of the interrupted transmission.

In block 506, the 6G BBU transmits the 6G fronthaul data and the 5G fronthaul data (the original 5G fronthaul data or the possibly modified 5G fronthaul data) to the radio unit. The 6G fronthaul data comprises the 6G user-plane data and 6G control-plane data, wherein the 6G control-plane data indicates the second set of radio resources intended for transmitting the 6G user-plane data over the air interface.

In block 507, the radio unit transmits, over the air interface, the 6G userplane data to one or more 6G UEs based on the 6G control-plane data. Furthermore, the radio unit transmits, over the air interface, the 5G user-plane data to one or more 5G UEs based on the 5G control-plane data.

In block 508, the 6G BBU may transmit, to the radio unit, an interrupted transmission indication for one or more 5G UEs, if puncturing was performed for the 5G resources.

In block 509, the radio unit may transmit the interrupted transmission indication to the one or more 5G UEs over the air interface. For example, the interrupted transmission indication may be transmitted to the one or more 5G UEs on the GC-PDCCH monitored by the one or more 5G UEs based on the CORESET.

For the above solutions, it may be beneficial to account for the additional delay that may be introduced from the processing of the 5G fronthaul data at the 6G BBU. Additional BBU processing time may lead to hybrid automatic repeat request (HARQj processes getting stalled, i.e., inability to meet peak data rates. The consequence of this would be to reduce the maximum fronthaul latency. The maximum allowed latency on the fronthaul may have a dependency on the number of allowed HARQ processes as well as the UE and BBU processing times. It should also be noted that although today’s implementations may require higher processing time, the higher processing power that is expected to be available when 6G is deployed, as per Moore’s law, may reduce the gNB and 6G BBU processing times.

Furthermore, in one option, the 6G BBU may perform scheduling, if all the resources it wants are available (e.g., no puncturing, but allocating unused 5G resource blocks and employing different beams for 5G and 6GJ. Hence, in this scenario, the 6G BBU may just select a pre-scheduled set of UEs that fits within the planned 5 G transmissions and send the 5G and 6G aggregated fronthaul data to the RU. This type of solution could operate with even shorter 6G BBU processing times.

FIG. 6 illustrates a flow chart according to an example embodiment of a method performed by an apparatus. For example, the apparatus may be, or comprise, or be comprised in, a network node of a radio access network. The network node may also be referred to, for example, as a base station, an access node, a gNB, a baseband unit, or a distributed unit. The apparatus may correspond to, for example, the access node 104 or DU 105 of FIG. 1, or the 5G DU 203 of FIG. 2A or FIG. 2B, or the 6G DU 304 of FIG. 3A or FIG. 3B, or the 6G BBU of FIG. 4 or FIG. 5.

Referring to FIG. 6, in block 601, first fronthaul data associated with a first radio access technology is received, the first fronthaul data comprising first user-plane data and first control-plane data, wherein the first control-plane data indicates a first set of radio resources intended for transmitting the first user-plane data over an air interface.

For example, the first fronthaul data may be received via a fronthaul interface that is based on an ethernet common public radio interface (eCPRI) protocol or another protocol for fronthaul communication between the apparatus and a network node associated with the first radio access technology.

The apparatus may comprise, or be comprised in, a network node associated with a second radio access technology.

In block 602, a second set of radio resources is determined based on the first set of radio resources, the second set of radio resources intended for transmitting second user-plane data over the air interface, wherein the second user-plane data is associated with the second radio access technology. For example, the second set of radio resources may be determined such that there are no overlapping radio resources between the first set of radio resources and the second set of radio resources, or at least such that the number of overlapping radio resources is as low as possible.

The first radio access technology may be based on a different radio access technology than the second radio access technology. For example, the first radio access technology may comprise a 5G radio access technology, and the second radio access technology may comprise a 6G radio access technology. As another example, the first radio access technology may comprise a 4G radio access technology, and the second radio access technology may comprise a 5G radio access technology.

Alternatively, the first radio access technology may be based on a same radio access technology as the second radio access technology. For example, the first radio access technology may refer to a 6G small cell, and the second radio access technology may refer to a 6G macro cell.

In block 603, at least second fronthaul data is transmitted to a radio unit, the second fronthaul data comprising the second user-plane data and second control-plane data, wherein the second control-plane data indicates the second set of radio resources intended for transmitting the second user-plane data over the air interface.

FIG. 7 illustrates a flow chart according to an example embodiment of a method performed by an apparatus. For example, the apparatus may be, or comprise, or be comprised in, a network node of a radio access network. The network node may also be referred to, for example, as a base station, an access node, a gNB, a baseband unit, or a distributed unit. The apparatus may correspond to, for example, the access node 104 or DU 105 of FIG. 1, or the 5G DU 203 of FIG. 2A or FIG. 2B, or the 6G DU 304 of FIG. 3A or FIG. 3B, or the 6G BBU of FIG. 4 or FIG. 5.

In this example embodiment, the apparatus may perform scheduling if all the radio resources it wants are available. Hence, in this scenario, the apparatus may just select a pre-scheduled set of UEs that fits within the planned transmissions of the other RAT. The apparatus may then transmit the aggregated fronthaul data to the RU.

Referring to FIG. 7, in block 701, multiple sets of radio resources are pre-scheduled for a plurality of user devices associated with a second radio access technology, prior to receiving first fronthaul data associated with a first radio access technology.

Alternatively, the first radio access technology may be based on a same radio access technology as the second radio access technology. For example, the first radio access technology may refer to a 6G small cell, and the second radio access technology may refer to a 6G macro cell. In block 702, the first fronthaul data associated with the first radio access technology is received, the first fronthaul data comprising first user-plane data and first control-plane data, wherein the first control-plane data indicates a first set of radio resources intended for transmitting the first user-plane data over an air interface.

The apparatus may comprise, or be comprised in, a network node associated with the second radio access technology.

In block 703, a second set of radio resources is determined from the prescheduled multiple sets of radio resources based on the first set of radio resources, the second set of radio resources intended for transmitting second user-plane data over the air interface, wherein the second user-plane data is associated with the second radio access technology.

For example, the second set of radio resources may be determined by comparing the first set of radio resources with the pre-scheduled multiple sets of radio resources, and selecting a resource set from the pre-scheduled resource sets based on the comparison such that the selected resource set (i.e., the second set of radio resources) does not have any overlapping resources with the first set of radio resources. Thus, the second set of radio resources may comprise radio resources that are unused by the first set of radio resources, in which case there may be no need to puncture any resources in either set. In other words, in this case, there may be no overlapping resources between the first set of radio resources and the second set of radio resources.

In block 704, the first fronthaul data and second fronthaul data is transmitted to a radio unit, the second fronthaul data comprising the second userplane data and second control-plane data, wherein the second control-plane data indicates the second set of radio resources intended for transmitting the second user-plane data over the air interface. By transmitting the first fronthaul data, the apparatus may indicate the radio unit to transmit, based on the first control-plane data, the first user-plane data over the air interface to one or more user devices associated with the first radio access technology.

FIG. 8 illustrates a flow chart according to an example embodiment of a method performed by an apparatus. For example, the apparatus may be, or comprise, or be comprised in, a network node of a radio access network. The network node may also be referred to, for example, as a base station, an access node, a gNB, a baseband unit, or a distributed unit. The apparatus may correspond to, for example, the access node 104 or DU 105 of FIG. 1, or the 5G DU 203 of FIG. 2A or FIG. 2B, or the 6G DU 304 of FIG. 3A or FIG. 3B, or the 6G BBU of FIG. 4 or FIG. 5.

Referring to FIG. 8, in block 801, the apparatus receives, via an interface between the apparatus and a network node associated with a first radio access technology, a configuration for an interrupted transmission indication. For example, the configuration may be received via an Xn interface.

In block 802, first fronthaul data associated with the first radio access technology is received, the first fronthaul data comprising first user-plane data and first control-plane data, wherein the first control-plane data indicates a first set of radio resources intended for transmitting the first user-plane data over an air interface.

For example, the first fronthaul data may be received via a fronthaul interface that is based on an ethernet common public radio interface (eCPRI) protocol or another protocol for fronthaul communication between the apparatus and the network node associated with the first radio access technology.

In block 803, a second set of radio resources is determined based on the first set of radio resources, the second set of radio resources intended for transmitting second user-plane data over the air interface, wherein the second user-plane data is associated with the second radio access technology.

In block 804, the apparatus determines, based on the first set of radio resources, whether to perform puncturing for at least one of the first set of radio resources or the second set of radio resources (e.g., depending on which one of the resource sets is prioritized).

For example, if the first set of radio resources and the second set of radio resources comprise one or more overlapping radio resources, then the apparatus may determine to puncture the one or more overlapping radio resources in the first set of radio resources or the second set of radio resources. On the other hand, if there are no overlapping radio resources in the first set of radio resources and the second set of radio resources, then puncturing may not be needed.

In block 805, based on determining that puncturing is needed, one or more radio resources in the first set of radio resources intended for transmitting the first user-plane data are punctured, wherein the second set of radio resources comprises at least the punctured one or more radio resources. In this case, the second set of radio resources may have a higher priority compared to the first set of radio resources.

For example, the first control-plane data may indicate a priority order of the first set of radio resources relative to the second set of radio resources, wherein the one or more radio resources in the first set of radio resources are punctured based on the priority order indicating that the first set of radio resources is associated with a lower priority than a priority of the second set of radio resources.

Alternatively, or additionally, the first control-plane data may indicate one or more protected radio resources that are not to be punctured in the first set of radio resources, in which case the apparatus may avoid puncturing the one or more protected radio resources in the first set of radio resources. In other words, the punctured one or more radio resources do not comprise the one or more protected radio resources.

In block 806, modified first fronthaul data is obtained by modifying the first fronthaul data based on the puncturing. For example, at least the first controlplane data in the first fronthaul data may be modified to reflect the puncturing, in order to indicate the punctured one or more radio resources to a radio unit (i.e., so that the radio unit does not transmit the first user-plane data on the punctured resources).

In block 807, the modified first fronthaul data and second fronthaul data are transmitted to the radio unit, the second fronthaul data comprising the second user-plane data and second control-plane data, wherein the second control-plane data indicates the second set of radio resources intended for transmitting the second user-plane data over the air interface.

By transmitting the modified first fronthaul data, the apparatus may indicate the radio unit to transmit, based on the first control-plane data of the modified first fronthaul data, the first user-plane data of the modified first fronthaul data over the air interface to one or more user devices associated with the first radio access technology.

In block 808, the apparatus transmits, to the radio unit, an interrupted transmission indication for one or more user devices associated with the first radio access technology, wherein the interrupted transmission indication is transmitted based on puncturing the one or more radio resources in the first set of radio resources intended for transmitting the first user-plane data to the one or more user devices. The interrupted transmission indication may be based on the configuration received in block 801. For example, the configuration may indicate a control resource set (CORESET) shared between the first radio access technology and the second radio access technology, in which case the interrupted transmission indication may be based on the CORESET. The one or more user devices associated with the first radio access technology may be configured to monitor a group common physical downlink control channel (GC-PDCCH) based on the CORESET.

For example, in case the first radio access technology refers to 5G, and the second radio access technology refers to 6G, then 5G user devices may monitor the GC-PDCCH on the control resources indicated in the CORESET, and the interrupted transmission indication may be transmitted from the 6G cell on the GC- PDCCH by using the control resources indicated in the CORESET. Thus, the 5G user devices would detect the interrupted transmission indication transmitted from the 6G cell, since they would be monitoring those control resources. In other words, the CORESET comprises a set of control resources over which the 5G user devices search for the GC-PDCCH, on which the interrupted transmission indication may be transmitted from the radio unit.

FIG. 9 illustrates a flow chart according to an example embodiment of a method performed by an apparatus. For example, the apparatus may be, or comprise, or be comprised in, a network node of a radio access network. The network node may also be referred to, for example, as a base station, an access node, a gNB, a baseband unit, or a distributed unit. The apparatus may correspond to, for example, the access node 104 or DU 105 of FIG. 1, or the 5G DU 203 of FIG. 2A or FIG. 2B, or the 6G DU 304 of FIG. 3A or FIG. 3B, or the 6G BBU of FIG. 4 or FIG. 5.

Referring to FIG. 9, in block 901, first fronthaul data associated with a first radio access technology is received, the first fronthaul data comprising first user-plane data and first control-plane data, wherein the first control-plane data indicates a first set of radio resources intended for transmitting the first user-plane data over an air interface.

In block 902, a second set of radio resources is determined based on the first set of radio resources, the second set of radio resources intended for transmitting second user-plane data over the air interface, wherein the second user-plane data is associated with the second radio access technology.

In block 903, the apparatus determines, based on the first set of radio resources, whether to perform puncturing for at least one of the first set of radio resources or the second set of radio resources (e.g., depending on which one of the resource sets is prioritized).

In block 904, based on determining that puncturing is needed, one or more radio resources in the second set of radio resources intended for transmitting the second user-plane data are punctured, wherein the first set of radio resources comprises at least the punctured one or more radio resources. In this case, the first set of radio resources may have a higher priority compared to the second set of radio resources.

For example, the first control-plane data may indicate a priority order of the first set of radio resources relative to the second set of radio resources, wherein the one or more radio resources in the second set of radio resources are punctured based on the priority order indicating that the second set of radio resources is associated with a lower priority than a priority of the first set of radio resources.

Alternatively, or additionally, the first control-plane data may indicate one or more protected radio resources that are not to be punctured in the first set of radio resources. For example, in case some or all of the overlapping radio resource(s) between the first set of radio resources and the second set of radio resources are protected resource(s), then the apparatus may determine to puncture the one or more resources in the second set of radio resources instead of puncturing them in the first set of radio resources (in which those resources are protected).

In block 905, the first fronthaul data and second fronthaul data are transmitted to a radio unit, the second fronthaul data comprising the second userplane data and second control-plane data, wherein the second control-plane data indicates the (punctured) second set of radio resources intended for transmitting the second user-plane data over the air interface. In this case, the second set of radio resources indicated to the radio unit does not comprise the one or more radio resources that were punctured in the second set of radio resources.

The blocks, related functions, and information exchanges (messages) described above by means of FIGS. 4-9 are in no absolute chronological order, and some of them may be performed simultaneously or in an order differing from the described one. Other functions can also be executed between them or within them, and other information may be sent, and/or other rules applied. Some of the blocks or part of the blocks or one or more pieces of information can also be left out or replaced by a corresponding block or part of the block or one or more pieces of information.

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.

FIG. 10 illustrates an example of an apparatus 1000 comprising means for performing one or more of the example embodiments described above. For example, the apparatus 1000 may be an apparatus such as, or comprising, or comprised in, a network node of a radio access network. The network node may also be referred to, for example, as a base station, an access node, a gNB, a baseband unit, or a distributed unit. The apparatus 1000 may correspond to, for example, the access node 104 or DU 105 of FIG. 1, or the 5G DU 203 of FIG. 2A or FIG. 2B, or the 6G DU 304 of FIG. 3A or FIG. 3B, or the 6G BBU of FIG. 4 or FIG. 5.

The apparatus 1000 may comprise, for example, a circuitry or a chipset applicable for realizing one or more of the example embodiments described above. The apparatus 1000 maybe an electronic device comprising one or more electronic circuitries. The apparatus 1000 may comprise a communication control circuitry 1010 such as at least one processor, and at least one memory 1020 storing instructions 1022 which, when executed by the at least one processor, cause the apparatus 1000 to carry out one or more of the example embodiments described above. Such instructions 1022 may, for example, include a computer program code (software), wherein the at least one memory and the computer program code (software) are configured, with the at least one processor, to cause the apparatus 1000 to carry out one or more of the example embodiments described above. The at least one processor and the at least one memory storing the instructions may provide the means for providing or causing the performance of any of the methods and/or blocks described above.

The processor is coupled to the memory 1020. The processor is configured to read and write data to and from the memory 1020. The memory 1020 may comprise one or more memory units. The memory units may be volatile or non-volatile. It is to be noted that there may be one or more units of non-volatile memory and one or more units of volatile memory or, alternatively, one or more units of non-volatile memory, or, alternatively, one or more units of volatile memory. Volatile memory may be for example random-access memory (RAM), dynamic random-access memory (DRAM) or synchronous dynamic random-access memory (SDRAM). Non-volatile memory may be for example read-only memory (ROM), programmable read-only memory (PROM), electronically erasable programmable read-only memory (EEPROM), flash memory, optical storage or magnetic storage. In general, memories may be referred to as non-transitory computer readable media. 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). The memory 1020 stores computer readable instructions that are executed by the processor. For example, non-volatile memory stores the computer readable instructions, and the processor executes the instructions using volatile memory for temporary storage of data and/or instructions.

The computer readable instructions may have been pre-stored to the memory 1020 or, alternatively or additionally, they may be received, by the apparatus, via an electromagnetic carrier signal and/or may be copied from a physical entity such as a computer program product. Execution of the computer readable instructions causes the apparatus 1000 to perform one or more of the functionalities described above.

The memory 1020 may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory and/or removable memory. The memory may comprise a configuration database for storing configuration data. For example, the configuration database may store a current neighbour cell list, and, in some example embodiments, structures of the frames used in the detected neighbour cells.

The apparatus 1000 may further comprise a communication interface 1030 comprising hardware and/or software for realizing communication connectivity according to one or more communication protocols. The communication interface 1030 may comprise at least one transmitter (Tx) and at least one receiver (Rx) that may be integrated to the apparatus 1000 or that the apparatus 1000 may be connected to. The communication interface 1030 may provide means for performing some of the blocks for one or more example embodiments described above. The communication interface 1030 may comprise one or more components, such as: power amplifier, digital front end (DFE), analog- to-digital converter (ADC), digital -to-analog converter (DAC), frequency converter, (de) modulator, and/or encoder/decoder circuitries, controlled by the corresponding controlling units.

The communication interface may, for example, provide an interface to a radio unit and/or one or more other network nodes (e.g., BBU or DU) of the cellular communication system. The apparatus 1000 may further comprise another interface towards a core network such as the network coordinator apparatus or AMF.

The apparatus 1000 may further comprise a scheduler 1040 that is configured to allocate radio resources. The scheduler 1040 may be configured along with the communication control circuitry 1010 or it may be separately configured.

It is to be noted that the apparatus 1000 may further comprise various components not illustrated in FIG. 10. The various components may be hardware components and/or software components.

As used in this application, the term "circuitry” may refer to one or more or all of the following: a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry); and b) combinations of hardware circuits and software, such as (as applicable): i) a combination of analog and/or digital hardware circuit(s) with software/firmware and ii) any portions of hardware processor(s) with software (including digital signal processor(s), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone, to perform various functions); and c) hardware circuit(s) and/or processor(s), such as a microprocessor^) or a portion of a microprocessor^), that requires software (for example firmware) for operation, but the software may not be present when it is not needed for operation.

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

The techniques and methods described herein may be implemented by various means. For example, these techniques may be implemented in hardware (one or more devices), firmware (one or more devices), software (one or more modules), or combinations thereof. For a hardware implementation, the apparatus(es) of example embodiments may be implemented within one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), graphics processing units (GPUs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof. For firmware or software, the implementation can be carried out through modules of at least one chipset (for example procedures, functions, and so on) that perform the functions described herein. The software codes may be stored in a memory unit and executed by processors. The memory unit may be implemented within the processor or externally to the processor. In the latter case, it can be communicatively coupled to the processor via various means, as is known in the art. Additionally, the components of the systems described herein may be rearranged and/or complemented by additional components in order to facilitate the achievements of the various aspects, etc., described with regard thereto, and they are not limited to the precise configurations set forth in the given figures, as will be appreciated by one skilled in the art.

It will be obvious to a person skilled in the art that, as technology advances, the inventive concept may be implemented in various ways. The embodiments are not limited to the example embodiments described above, but may vary within the scope of the claims. Therefore, all words and expressions should be interpreted broadly, and they are intended to illustrate, not to restrict, the example embodiments.

Claims

1. An apparatus comprising at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive first fronthaul data associated with a first radio access technology, the first fronthaul data comprising first user-plane data and first control-plane data, wherein the first control-plane data indicates a first set of radio resources intended for transmitting the first user-plane data over an air interface; determine, based on the first set of radio resources, a second set of radio resources intended for transmitting second user-plane data over the air interface, wherein the second user-plane data is associated with a second radio access technology; and transmit, to a radio unit, at least second fronthaul data comprising the second user-plane data and second control-plane data, wherein the second controlplane data indicates the second set of radio resources intended for transmitting the second user-plane data over the air interface.

2. The apparatus according to claim 1, wherein the first radio access technology is based on a different radio access technology than the second radio access technology.

3. The apparatus according to any preceding claim, wherein the first radio access technology comprises a fifth generation, 5G, radio access technology, and the second radio access technology comprises a sixth generation, 6G, radio access technology.

4. The apparatus according to any of claims 1-2, wherein the first radio access technology comprises a fourth generation, 4G, radio access technology, and the second radio access technology comprises a fifth generation, 5G, radio access technology.

5. The apparatus according to claim 1, wherein the first radio access technology is based on a same radio access technology as the second radio access technology.

6. The apparatus according to any preceding claim, wherein the first fronthaul data is received via a fronthaul interface that is based on an ethernet common public radio interface, eCPRI, protocol or another protocol for fronthaul communication between the apparatus and a network node associated with the first radio access technology.

7. The apparatus according to any preceding claim, wherein the apparatus comprises, or is comprised in, a network node associated with the second radio access technology.

8. The apparatus according to any preceding claim, further being caused to: determine, based on the first set of radio resources, whether to perform puncturing for at least one of the first set of radio resources or the second set of radio resources.

9. The apparatus according to any preceding claim, further being caused to: puncture one or more radio resources in the first set of radio resources intended for transmitting the first user-plane data, wherein the second set of radio resources comprises at least the punctured one or more radio resources; obtain modified first fronthaul data by modifying the first fronthaul data based on the puncturing; and transmit the modified first fronthaul data to the radio unit.

10. The apparatus according to claim 9, further being caused to: indicate the radio unit to transmit, based on the first control-plane data of the modified first fronthaul data, the first user-plane data of the modified first fronthaul data over the air interface to one or more user devices associated with the first radio access technology.

11. The apparatus according to any of claims 9-10, wherein the first control-plane data indicates one or more protected radio resources that are not to be punctured in the first set of radio resources, wherein the punctured one or more radio resources do not comprise the one or more protected radio resources.

12. The apparatus according to any of claims 9-11, wherein the first control-plane data indicates a priority order of the first set of radio resources relative to the second set of radio resources, wherein the one or more radio resources in the first set of radio resources are punctured based on the priority order indicating that the first set of radio resources is associated with a lower priority than a priority of the second set of radio resources.

13. The apparatus according to any of claims 9-12, further being caused to: transmit, to the radio unit, an interrupted transmission indication for one or more user devices associated with the first radio access technology, wherein the interrupted transmission indication is transmitted based on puncturing the one or more radio resources in the first set of radio resources intended for transmitting the first user-plane data to the one or more user devices.

14. The apparatus according to claim 13, further being caused to: receive, via an interface between the apparatus and a network node associated with the first radio access technology, a configuration for the interrupted transmission indication, wherein the interrupted transmission indication is based on the configuration.

15. The apparatus according to any of claims 13-14, wherein the interrupted transmission indication is based on a control resource set, CORESET, shared between the first radio access technology and the second radio access technology, the one or more user devices associated with the first radio access technology being configured to monitor a group common physical downlink control channel, GC-PDCCH, based on the CORESET.

16. The apparatus according to any of claims 1-8, further being caused to: puncture one or more radio resources in the second set of radio resources intended for transmitting the second user-plane data, wherein the first set of radio resources comprises at least the punctured one or more radio resources.

17. The apparatus according to claim 16, wherein the first control-plane data indicates a priority order of the first set of radio resources relative to the second set of radio resources, wherein the one or more radio resources in the second set of radio resources are punctured based on the priority order indicating that the second set of radio resources is associated with a lower priority than a priority of the first set of radio resources.

18. The apparatus according to any of claims 1-8, further being caused to: transmit the first fronthaul data to the radio unit, wherein the second set of radio resources comprises radio resources that are unused by the first set of radio resources.

19. The apparatus according to claim 18, further being caused to: indicate the radio unit to transmit, based on the first control-plane data, the first user-plane data over the air interface to one or more user devices associated with the first radio access technology.

20. The apparatus according to any preceding claim, further being caused to: pre-schedule, prior to receiving the first fronthaul data, multiple sets of radio resources for a plurality of user devices associated with the second radio access technology, wherein the second set of radio resources is determined from the pre-scheduled multiple sets of radio resources based on the first set of radio resources.

21. An apparatus comprising: means for receiving first fronthaul data associated with a first radio access technology, the first fronthaul data comprising first user-plane data and first control-plane data, wherein the first control-plane data indicates a first set of radio resources intended for transmitting the first user-plane data over an air interface; means for determining, based on the first set of radio resources, a second set of radio resources intended for transmitting second user-plane data over the air interface, wherein the second user-plane data is associated with a second radio access technology; and means for transmitting, to a radio unit, at least second fronthaul data comprising the second user-plane data and second control-plane data, wherein the second control-plane data indicates the second set of radio resources intended for transmitting the second user-plane data over the air interface.

22. A method comprising: receiving first fronthaul data associated with a first radio access technology, the first fronthaul data comprising first user-plane data and first control-plane data, wherein the first control-plane data indicates a first set of radio resources intended for transmitting the first user-plane data over an air interface; determining, based on the first set of radio resources, a second set of radio resources intended for transmitting second user-plane data over the air interface, wherein the second user-plane data is associated with a second radio access technology; and transmitting, to a radio unit, at least second fronthaul data comprising the second user-plane data and second control-plane data, wherein the second control-plane data indicates the second set of radio resources intended for transmitting the second user-plane data over the air interface.

23. A non-transitory computer readable medium comprising program instructions which, when executed by an apparatus, cause the apparatus to perform at least the following: receiving first fronthaul data associated with a first radio access technology, the first fronthaul data comprising first user-plane data and first control-plane data, wherein the first control-plane data indicates a first set of radio resources intended for transmitting the first user-plane data over an air interface; determining, based on the first set of radio resources, a second set of radio resources intended for transmitting second user-plane data over the air interface, wherein the second user-plane data is associated with a second radio access technology; and transmitting, to a radio unit, at least second fronthaul data comprising the second user-plane data and second control-plane data, wherein the second control-plane data indicates the second set of radio resources intended for transmitting the second user-plane data over the air interface.

24. A system comprising at least a first network node associated with a first radio access technology, a second network node associated with a second radio access technology, and a radio unit; wherein the first network node is configured to: transmit, to the second network node or to the radio unit, first fronthaul data associated with the first radio access technology, the first fronthaul data comprising first user-plane data and first control-plane data, wherein the first control-plane data indicates a first set of radio resources intended for transmitting the first user-plane data over an air interface of the radio unit; wherein the second network node is configured to: receive, from the first network node or the radio unit, the first fronthaul data; determine, based on the first set of radio resources, a second set of radio resources intended for transmitting second user-plane data over the air interface, wherein the second user-plane data is associated with the second radio access technology; and transmit, to the radio unit, at least second fronthaul data comprising the second user-plane data and second control-plane data, wherein the second controlplane data indicates the second set of radio resources intended for transmitting the second user-plane data over the air interface; wherein the radio unit is configured to: receive, from the second network node, at least the second fronthaul data.

25. The system according to claim 24, wherein the second network node is further configured to: transmit the first fronthaul data to the radio unit; wherein the radio unit is configured to: transmit, based on the first control-plane data, the first user-plane data over the air interface to one or more user devices associated with the first radio access technology; and transmit, based on the second control-plane data, the second user-plane data over the air interface to one or more user devices associated with the second radio access technology.

26. The system according to claim 24, wherein the second network node is further configured to: puncture one or more radio resources in the first set of radio resources intended for transmitting the first user-plane data, wherein the second set of radio resources comprises at least the punctured one or more radio resources; obtain modified first fronthaul data by modifying the first fronthaul data based on the puncturing; and transmit the modified first fronthaul data to the radio unit; wherein the radio unit is configured to: transmit, based on the first control-plane data of the modified first fronthaul data, the first user-plane data of the modified first fronthaul data over the air interface to one or more user devices associated with the first radio access technology; and transmit, based on the second control-plane data, the second user-plane data over the air interface to one or more user devices associated with the second radio access technology.