WO2024227967A1

WO2024227967A1 - Device for a network node

Info

Publication number: WO2024227967A1
Application number: PCT/FI2023/050242
Authority: WO
Inventors: Janne Veikko Kaasalainen; Malgorzata Tomala; Tero Henttonen
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2023-05-03
Filing date: 2023-05-03
Publication date: 2024-11-07
Anticipated expiration: 2025-11-03
Also published as: CN121128245A

Abstract

A device for a network node is provided. The device comprises at least one processor, and at least one memory including computer program code. The at least one memory and the computer program code are configured, with the at least one processor, to cause the device at least to send a notification using a first radio access technology to a user equipment that the device is configured to use a second radio access technology and that the network node is configured to use the first radio access technology, receive a message from the user equipment using the second radio access technology that the user equipment is capable of using the second radio access technology, forward parameters required for access to the second radio access technology to a central unit of the network node configured for the first radio access technology, receive a configuration for the second radio access technology from the central unit based on the parameters, and send the configuration for the second radio access technology to the user equipment using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2.

Description

DEVICE FOR A NETWORK NODE

TECHNICAL FIELD

Various example embodiments relate generally to telecommunications, and to a device for a network node allowing migration from a current radio access technology to a future radio access technology.

BACKGROUND

The Global Suppliers Association (GSA) and Hexa X II conduct activities to define and scope initial requirements for end-to-end 6G system design. Some form of migration solution from 4G/5G towards 6G is needed, and it is very likely that 6G will end up discussing some form of Non-Standalone (NSA) solution as a possible migration path to full use of 6G. How this is possible is dependent on the network architecture of 6G: In 6G the final architecture may be utilizing, for example Service-Based Architecture (SBA) that could require different network interfaces, or include converged core/RAN functionalities (e.g. combined CU/DU, which could be similar to 4G eNB). Therefore, it is possible that the current NG type of interface does not exist in 6G.

For the migration from 4G to 5G, a 5G Non-Standalone (NSA) solution was defined, in which a 5G Radio Access Node or 5G Node-B (gNB) 30 connects to a 4G Radio Access Network (RAN) using a 4G Radio Access Node (eNB) 20 and a 5G core network. The overall RRC architecture is shown in Figure 1. A terminal device or user equipment (UE) 10 can have a Radio Resource Control (RRC) connection over a 4G RAN, with 5G RRC being used as a container on top of the 4G RRC. This was realized by E-UTRAN - NR Dual Connectivity in which the UE 10, being connected to the 4G RAN Master Node (MeNB) 20, becomes additionally connected to 5G RAN by adding a link to a 5G Radio Access Node 30 as a Secondary Node (SgNB). Therefore, the 5G RRC connection is piggybacked on the 4G RRC. In this way, the UE 10 utilizes both 4G and 5G RRC at the same time via the Uu interface from the UE 10 to both the eNB 20 and the gNB 30. The eNB 20 and gNB 30 are connected via the X2-C interface. Figure 2 shows a basic signalling diagram depicting how the master node (4G eNB) 20 can add the 5G gNB 30 as a secondary node. The master node 20 requests a 5G configuration from the secondary node 30 and delivers it to the UE 10 using 4G RRC connection over the 4G RAN.

If the migration from 5G to 6G were to be done using a similar approach to that used between 4G and 5G, as described above, it could lead to major differences in a NS A based solution and a final standalone (SA) based solution. This would either limit the final 6G architecture options or different types of products would be needed for NSA and SA. Furthermore, if the migration is also required from 4G, yet another type of migration option will be needed.

Another problem in the E-UTRA-New Radio Dual Connectivity (EN-DC) type of NSA solution described above is that it works well in case the frequency bands are so different that secondary node (SN) cell coverage is much smaller than that from the cell served by the master node (MN). In this case, the MN cell helps to guarantee a robust RRC connection. However, if the frequency band is the same or having similar characteristics, this leads to the problem of how to split the frequency band. Furthermore, in UE implementation this could create a problem, as the UE may need to split the transmitter power between radios.

SUMMARY OF THE INVENTION

Accordingly, an aspect of the present invention provides a device for a network node, the device comprising at least one processor, and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the device at least to send a notification using a first radio access technology to a user equipment that the device is configured to use a second radio access technology and that the network node is configured to use the first radio access technology, receive a message from the user equipment using the second radio access technology that the user equipment is capable of using the second radio access technology, forward parameters required for access to the second radio access technology to a central unit of the network node configured for the first radio access technology, receive a configuration for the second radio access technology from the central unit based on said parameters, and send the configuration for the second radio access technology to the user equipment using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2. The device can be a non- standalone (NSA) radio device.

The configuration for the second radio access technology can be sent to the user equipment using the third and/or higher layers of the first radio access technology.

The device can be configured for incorporation into a core network part of a network.

The device can be connectable to the core network of the first radio access technology via an interface.

The first radio access technology can be 5G and the second radio access technology can be a future radio access technology. The future radio access technology can be 6G.

According to an aspect of the invention, there is provided an apparatus for a network node, comprising means for sending a notification using a first radio access technology to a user equipment that the apparatus is configured to use a second radio access technology, and that the network node is configured to use the first radio access technology, means for receiving a message using the second radio access technology from the user equipment that the user equipment is capable of using the second radio access technology, means for forwarding parameters required for access to the second radio access technology to a central unit of the network node configured for the first radio access technology, means for receiving a configuration for the second radio access technology from the central unit based on said parameters, and means for sending the configuration for the second radio access technology to the user equipment using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2.

According to an aspect of the present invention there is provided a device for a network node. The device comprises at least one processor, and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the device at least to send a notification in a first radio access technology to a user equipment that the device is configured to use a second radio access technology, and that the network node is configured to access a network using the first radio access technology, receive a message using the second radio access technology from the user equipment that the user equipment is capable of operating using the second radio access technology, forward parameters required for access to the second radio access technology to the network using the first radio technology, receive a configuration from the network for the second radio access technology based on said parameters, and send the configuration for the second radio access technology to the user equipment using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2.

According to an aspect of the present invention, there is provided a network node. The network node comprises a central unit configured for a first radio access technology, a first distributed unit configured for the first radio access technology and connected to the central unit, and a second distributed unit connected to the central unit and configured for a second radio access technology. The second distributed unit comprises a transmitter configured to send a notification in the first radio access technology to a user equipment that the network node is configured to access a network using the first radio access technology and the second distributed unit is configured to operate using a second radio access technology, a receiver configured to receive a message using the second radio access technology from the user equipment that the user equipment is capable of operating using the second radio access technology, and a processor configured to forward parameters required for access to the second radio access technology to the central unit. The processor is further configured to receive a configuration for the second radio access technology from the central unit based on said parameters, and the transmitter is further configured to send the configuration for the second radio access technology to the user equipment using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2.

According to another aspect of the invention there is provided a network node, comprising a central unit configured for the first radio access technology, and a radio device configured for a second radio access technology. The radio device comprises at least one processor, and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the radio device at least to send a notification using the first radio access technology to a user equipment of a capability of the radio device to operate using a second radio access technology, receive a message using the second radio access technology from the user equipment that the user equipment is capable of operating using the second radio access technology, forward parameters required for access to the second radio access technology to the central unit of the network node configured for the first radio access technology, receive a configuration for the second radio access technology from the central unit based on said parameters, and send the configuration for the second radio access technology to the user equipment using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2.

The message can be a RRC set up request message.

The at least one memory and the computer program code can be further configured, with the at least one processor, to cause the network node at least to receive an addition request from a second network node configured for a third radio access technology to add the radio device using the second radio access technology to a network using the third radio access technology, send a request using the first radio access technology to the radio device for a configuration for the second radio access technology in response to receiving the addition request, receive a configuration for the second radio access technology using the first radio access technology, send the configuration for the second radio access technology to the second network node for configuring the user equipment using the third radio access technology to access the second radio access technology.

The first radio access technology (RAN) can be 5G, the second RAN can be 6G and the third RAN can be 4G. The network node can be a gNB for providing access to a 5G network. The second network node can be a eNB for providing access to a 4G network.

According to an aspect of the invention, there is provided user equipment for operation in at least a first radio access technology and a second radio access technology, the user equipment comprising at least one processor, and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the user equipment at least to receive a notification using the first radio access technology from a network node configured for the first radio technology that the network node is capable of providing network access using the second radio technology, send a message using the second radio access technology to the network node that the user equipment is capable of operating using the second radio access technology, receive a configuration for the second radio access technology from the network node using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2, and configure the user equipment for the second radio access technology and set up a signalling radio bearer for the second radio access technology between the user equipment and the network node using the configuration.

According to an aspect of the present invention, there is provided an apparatus, comprising means for receiving a notification using a first radio access technology from a network node configured for the first radio technology that the network node is capable of providing network access using a second radio technology, means for sending an indication using the second radio access technology to the network node that the apparatus is capable of operating using the second radio access technology, means for receiving a configuration for the second radio access technology from the network node using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2, and means for configuring the apparatus for the second radio access technology and setting up a signalling radio bearer for the second radio access technology between the apparatus and the network node using the configuration.

The apparatus can be user equipment (UE) or terminal device.

According to an aspect of the present invention, there is provided a method, comprising sending a notification in a first radio access technology from a network node to a user equipment of a capability of the network node to provide network access in a second radio access technology, receiving a message using the second radio access technology from the user equipment that the user equipment is capable of operating using the second radio access technology, forwarding parameters required for access to the second radio access technology to a central unit of the network node configured for the first radio access technology, receiving a configuration for the second radio access technology from the central unit based on said parameters, and sending the configuration for the second radio access technology to the user equipment using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2.

The message can be a RRC setup request message.

The parameters can be forwarded using initial uplink RRC message transfer.

The configuration can be received using downlink RRC message transfer.

The configuration for the second radio access technology can be sent to the user equipment by piggybacking on a RRC connection using the first radio access technology.

An RRC configuration for the second radio access technology may be encapsulated in a CellGroupConfig of the first radio access technology.

The method can further comprise receiving a request from a second network node requesting to connect to the network node using a third radio access technology, requesting a configuration for the second network node using the third radio access technology, receiving the configuration for the second network node, forwarding the configuration for the second network node to the central unit of the network node using the second radio access technology, receiving a message from a user equipment indicating a capability of the user equipment to operate in the second radio access network, forwarding capability parameters required for access to the second radio access network from the user equipment to the second network node, receiving a configuration at the second network node for the second radio access technology based on said capability parameters, and sending the configuration for the second radio access technology to the user equipment using the third radio access technology.

The first radio access technology can be 5G, the second radio technology can be 6G and the third radio access technology can be 4G.

The first network node can be a gNB configured for 5G network access and the second network node can be an eNB configured for 4G network access.

According to an aspect of the invention, there is provided a method comprising receiving a notification at a user equipment using a first radio access technology from a network node configured for the first radio technology that the network node is capable of providing network access using the second radio technology, sending a message using the second radio access technology to the network node that the user equipment is capable of operating using the second radio access technology, receiving a configuration for the second radio access technology from the network node using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2, and configuring the user equipment for the second radio access technology and setting up a signalling radio bearer for the second radio access technology between the user equipment and the network node using the configuration.

According to an aspect of the invention, there is provided a computer program product embodied on a distribution medium readable by a computer and comprising program instructions which, when the program is executed by an apparatus, cause the apparatus to carry out a method comprising sending a notification in a first radio access technology from a network node to a user equipment of a capability of the network node to provide network access in a second radio access technology, receiving a message using the second radio access technology from the user equipment that the user equipment is capable of operating using the second radio access technology, forwarding parameters required for access to the second radio access technology to a central unit of the network node configured for the first radio access technology, receiving a configuration for the second radio access technology from the central unit based on said parameters, and sending the configuration for the second radio access technology to the user equipment using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2.

According to an aspect of the invention, there is provided a computer program product embodied on a distribution medium readable by a computer and comprising program instructions which, when the program is executed by an apparatus, cause the apparatus to carry out a method comprising receiving a notification at a user equipment using a first radio access technology from a network node configured for the first radio technology that the network node is capable of providing network access using the second radio technology, sending a message using the second radio access technology to the network node that the user equipment is capable of operating using the second radio access technology, receiving a configuration for the second radio access technology from the network node using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2, and configuring the user equipment for the second radio access technology and setting up a signalling radio bearer for the second radio access technology between the user equipment and the network node using the configuration.

According to an aspect of the present invention, there is provided a computer program product comprising program instructions which, when the program is executed by an apparatus, cause the apparatus to carry out a method comprising sending a notification in a first radio access technology from a network node to a user equipment of a capability of the network node to provide network access in a second radio access technology, receiving a message using the second radio access technology from the user equipment that the user equipment is capable of operating using the second radio access technology, forwarding parameters required for access to the second radio access technology to a central unit of the network node configured for the first radio access technology, receiving a configuration for the second radio access technology from the central unit based on said parameters, and sending the configuration for the second radio access technology to the user equipment using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2.

According to an aspect of the present invention, there is provided a computer program product comprising program instructions which, when the program is executed by an apparatus, cause the apparatus to carry out a method comprising receiving a notification at a user equipment using a first radio access technology from a network node configured for the first radio technology that the network node is capable of providing network access using the second radio technology, sending a message using the second radio access technology to the network node that the user equipment is capable of operating using the second radio access technology, receiving a configuration for the second radio access technology from the network node using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2, and configuring the user equipment for the second radio access technology and setting up a signalling radio bearer for the second radio access technology between the user equipment and the network node using the configuration.

According to an aspect of the present invention, there is provided a computer system, comprising one or more processors, at least one data storage, and one or more computer program instructions to be executed by the one or more processors in association with the at least one data storage for carrying out a method comprising sending a notification in a first radio access technology from a network node to a user equipment of a capability of the network node to provide network access in a second radio access technology, receiving a message using the second radio access technology from the user equipment that the user equipment is capable of operating using the second radio access technology, forwarding parameters required for access to the second radio access technology to a central unit of the network node configured for the first radio access technology, receiving a configuration for the second radio access technology from the central unit based on said parameters, and sending the configuration for the second radio access technology to the user equipment using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2.

According to an aspect of the present invention, there is provided a computer system, comprising one or more processors, at least one data storage, and one or more computer program instructions to be executed by the one or more processors in association with the at least one data storage for carrying out a method comprising receiving a notification at a user equipment using a first radio access technology from a network node configured for the first radio technology that the network node is capable of providing network access using the second radio technology, sending a message using the second radio access technology to the network node that the user equipment is capable of operating using the second radio access technology, receiving a configuration for the second radio access technology from the network node using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2, and configuring the user equipment for the second radio access technology and setting up a signalling radio bearer for the second radio access technology between the user equipment and the network node using the configuration.

LIST OF FIGURES

The invention will now be described with reference to the embodiments, and to the accompanying drawings, in which:

Figure 1 is a block diagram of network nodes in a configuration for a non- standalone solution for 4G to 5G migration;

Figure 2 is a message flow diagram for the network shown in Figure 1;

Figure 3 shows an example of a network to which one or more embodiments are applicable;

Figure 4 is a block diagram of network components featuring a device according to an embodiment of the invention;

Figure 5 is a flow diagram representing a method performed by a device according to an embodiment of the invention;

Figure 6 is a message flow diagram representing a method according to an embodiment of the invention;

Figure 7 is a flow diagram representing a method performed by a UE or terminal device according to an embodiment of the invention;

Figure 8 is a block diagram showing a network node and a device according to an embodiment of the invention;

Figure 9 is a flow diagram representing a method performed by a device according to an embodiment of the invention;

Figure 10 is a block diagram of network components featuring a device according to an embodiment of the invention;

Figure 11 is a flow diagram representing a method performed by a device according to an embodiment of the invention; Figure 12 is a message flow diagram representing a method according to an embodiment of the invention;

Figure 13 is a block diagram schematically representing circuitry of a UE for performing a method according to an embodiment of the invention; and

Figure 14 is a block diagram schematically representing circuitry of a device for performing a method according to an embodiment of the invention.

DESCRIPTION OF EMBODIMENTS

The following embodiments are exemplary. Although the specification may refer to “an”, “one”, or “some” embodiment(s) in several locations of the text, this does not necessarily mean that each reference is made to the same embodiment(s), or that a particular feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments. For the purposes of the present disclosure, the phrases “at least one of A or B”, “at least one of A and B”, “A and/or B” means (A), (B), or (A and B). For the purposes of the present disclosure, the phrases “A or B” and “A and/or B” means (A), (B), or (A and B). For the purposes of the present disclosure, the phrase “A, B, and/or C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C).

It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments.

The embodiments described herein may be implemented in a radio system, such as one comprising at least one of the following radio access technologies (RATs): Worldwide Interoperability for Micro- wave Access (WiMAX), Global System for Mobile communications (GSM, 2G), GSM EDGE radio access Network (GERAN), General Packet Radio Service (GRPS), Universal Mobile Telecommunication System (UMTS, 3G) based on basic wideband-code division multiple access (W-CDMA), high-speed packet access (HSPA), Long Term Evolution (LTE), LTE- Advanced, and enhanced LTE (eLTE). Term ‘eLTE’ here denotes the LTE evolution that connects to a 5G core. LTE is also known as evolved UMTS terrestrial radio access (EUTRA) or as evolved UMTS terrestrial radio access network (EUTRAN). A term “resource” may refer to radio resources, such as a physical resource block (PRB), a radio frame, a subframe, a time slot, a subband, a frequency region, a subcarrier, a beam, etc. The term “transmission” and/or “reception” may refer to wirelessly transmitting and/or receiving via a wireless propagation channel on radio resources.

The embodiments are not, however, restricted to the systems/RATs given as an example but a person skilled in the art may apply the solution to other communication systems/networks provided with necessary properties. Some examples of a suitable communication networks include a 5G network and/or a 6G network. The 3GPP solution to 5G is referred to as New Radio (NR). 6G is envisaged to be a further development of 5G. NR has been envisaged to use multiple-input-multiple-output (MIMO) multi-antenna transmission techniques, more base stations or nodes than the current network deployments of LTE (a so-called small cell concept), including macro sites operating in co-operation with smaller local area access nodes and perhaps also employing a variety of radio technologies for better coverage and enhanced data rates. 5G will likely be comprised of more than one radio access technology / radio access network (RAT/RAN), each optimized for certain use cases and/or spectrum. 5G mobile communications may have a wider range of use cases and related applications including video streaming, augmented reality, different ways of data sharing and various forms of machine type applications, including vehicular safety, different sensors and real-time control. 5G is expected to have multiple radio interfaces, namely below 6GHz, cmWave and mmWave, and being integrable with existing legacy radio access technologies, such as the LTE.

The current architecture in LTE networks is distributed in the radio and centralized in the core network. The low latency applications and services in 5G may require bringing the content close to the radio which leads to local break out and multi-access edge computing (MEC). 5G enables analytics and knowledge generation to occur at the source of the data. This approach requires leveraging resources that may not be continuously connected to a network such as laptops, smartphones, tablets and sensors. MEC provides a distributed computing environment for application and service hosting. It also has the ability to store and process content in close proximity to cellular subscribers for faster response time. Edge computing covers 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, real-time analytics, time-critical control, healthcare applications). Edge cloud may be brought into RAN by utilizing network function virtualization (NVF) 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 or base station comprising radio parts. Network slicing allows multiple virtual networks to be created on top of a common shared physical infrastructure. The virtual networks are then customised to meet the specific needs of applications, services, devices, customers or operators.

In radio communications, node operations may in be carried out, at least partly, in a central/centralized unit, CU, (e.g. server, host or node) operationally coupled to distributed unit, DU, (e.g. a radio head/node). It is also possible that node operations will be distributed among a plurality of servers, nodes or hosts. It should also be understood that the distribution of work between core network operations and base station operations may vary depending on implementation. Thus, 5G networks architecture may be based on a so-called CU-DU split. One gNB-CU controls several gNB-DUs. The term ‘gNB’ may correspond in 5G to the eNB in LTE. The gNBs (one or more) may communicate with one or more UEs. The gNB-CU (central node) may control a plurality of spatially separated gNB-DUs, acting at least as transmit/receive (Tx/Rx) nodes. In some embodiments, however, the gNB-DUs (also called DU) may comprise e.g. a radio link control (RLC), medium access control (MAC) layer and a physical (PHY) layer, whereas the gNB-CU (also called a CU) may comprise the layers above RLC layer, such as a packet data convergence protocol (PDCP) layer, a radio resource control (RRC) and an internet protocol (IP) layers. Other functional splits are possible too. It is considered that skilled person is familiar with the OSI model and the functionalities within each layer.

In an embodiment, the server or CU may generate a virtual network through which the server communicates with the radio node. In general, virtual networking may involve a process of combining hardware and software network resources and network functionality into a single, software -based administrative entity, a virtual network. Such virtual network may provide flexible distribution of operations between the server and the radio head/node. In practice, any digital signal processing task may be performed in either the CU or the DU and the boundary where the responsibility is shifted between the CU and the DU may be selected according to implementation.

Some other possible technology advancements to be used are Software-Defined Networking (SDN), Big Data, and all-IP, to mention only a few non-limiting examples. For example, network slicing may be a form of virtual network architecture using the same principles behind software defined networking (SDN) and network functions virtualisation (NFV) in fixed networks. SDN and NFV may deliver greater network flexibility by allowing traditional network architectures to be partitioned into virtual elements that can be linked (also through software). Network slicing allows multiple virtual networks to be created on top of a common shared physical infrastructure. The virtual networks are then customised to meet the specific needs of applications, services, devices, customers or operators.

The plurality of gNBs (access points/nodes), each comprising the CU and one or more DUs, may be connected to each other via the Xn interface over which the gNBs may negotiate. The gNBs may also be connected over next generation (NG) interfaces to a 5G core network (5GC), which may be a 5G equivalent for the core network of LTE. Such 5G CU-DU split architecture may be implemented using cloud/server so that the CU having higher layers locates in the cloud and the DU is closer to or comprises actual radio and antenna unit. There are similar plans ongoing for LTE/LTE-A/eLTE as well. When both eLTE and 5G will use similar architecture in a same cloud hardware (HW), the next step may be to combine software (SW) so that one common SW controls both radio access networks/technologies (RAN/RAT). This may allow then new ways to control radio resources of both RANs. Furthermore, it may be possible to have configurations where the full protocol stack is controlled by the same HW and handled by the same radio unit as the CU.

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

5G may also utilize satellite communication to enhance or complement the coverage of 5G service, for example by providing backhauling. Possible use cases are 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 rail-way/maritime/aeronautical communications. Satellite communication may utilize geostationary earth orbit (GEO) satellite systems, but also low earth orbit (LEO) satellite systems, in particular mega-constellations (systems in which hundreds of (nano)satellites are deployed). Each satellite 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 a gNB located on-ground or in a satellite.

The embodiments may be also applicable to narrow-band (NB) Internet-of-things (loT) systems which may enable a wide range of devices and services to be connected using cellular telecommunications bands. NB-IoT is a narrowband radio technology designed for the Internet of Things (loT) and is one of technologies standardized by the 3rd Generation Partnership Project (3GPP). Other 3GPP loT technologies also suitable to implement the embodiments include machine type communication (MTC) and eMTC (enhanced Machine- Type Communication). NB-IoT focuses specifically on low cost, long battery life, and enabling a large number of connected devices. The NB-IoT technology is deployed “in-band” in spectrum allocated to Long Term Evolution (LTE) - using resource blocks within a normal LTE carrier, or in the unused resource blocks within a LTE carrier’ s guard-band - or “standalone” for deployments in dedicated spectrum.

The embodiments may be also applicable to device-to-device (D2D), machine-to-machine, peer-to-peer (P2P) communications. The embodiments may be also applicable to vehicle-to- vehicle (V2V), vehicle-to-infrastructure (V2I), infrastructure-to-vehicle (I2V), or in general to V2X or X2V communications.

Figure 3 illustrates an example of a communication system or communication network to which embodiments of the invention may be applied. The system may comprise a control node 110 providing one or more cells, such as cell 100, and a control node 112 providing one or more other cells, such as cell 102. Each cell may be, e.g., a macro cell, a micro cell, femto, or a pico cell, for example. In another point of view, the cell may define a coverage area or a service area of the corresponding access node. The control node 110, 112 may be an evolved Node B (eNB) as in the LTE and LTE-A, ng-eNB as in eLTE, gNB of 5G, or any other apparatus capable of controlling radio communication and managing radio resources within a cell. The control node 110, 112 may be called a base station, network node, or an access node. The system may be a cellular communication system composed of a radio access network of access nodes, each controlling a respective cell or cells. The access node 110 may provide user equipment (UE) 120 (one or more UEs) with wireless access to other networks such as the Internet. The wireless access may comprise downlink (DL) communication from the control node to the UE 120 and uplink (UL) communication from the UE 120 to the control node.

Additionally, although not shown, one or more local area access nodes may be arranged such that a cell provided by the local area access node at least partially overlaps the cell of the access node 110 and/or 112. The local area access node may provide wireless access within a sub-cell. Examples of the sub-cell may include a micro, pico and/or femto cell. Typically, the sub-cell provides a hot spot within a macro cell. The operation of the local area access node may be controlled by an access node under whose control area the sub-cell is provided. In general, the control node for the small cell may be likewise called a base station, network node, or an access node.

There may be a plurality of UEs 120, 122 in the system. Each of them may be served by the same or by different control nodes 110, 112. The UEs 120, 122 may communicate with each other, in case D2D communication interface is established between them.

The term “terminal device” or “UE” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE), a Subscriber Station (SS), a Portable Subscriber Station, a Mobile Station (MS), or an Access Terminal (AT). The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), USB dongles, smart devices, wireless customer-premises equipment (CPE), an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. In the following description, the terms “terminal device”, “communication device”, “terminal”, “user equipment” and “UE” may be used interchangeably.

In the case of multiple access nodes in the communication network, the access nodes may be connected to each other with an interface. LTE specifications call such an interface as X2 interface. For IEEE 802.11 network (i.e. wireless local area network, WLAN, WiFi), a similar interface may be provided between access points. An interface between an LTE access point and a 5G access point, or between two 5G access points may be called Xn. Other communication methods between the access nodes may also be possible. The access nodes 110 and 112 may be further connected via another interface to a core network 116 of the cellular communication system. The LTE specifications specify the core network as an evolved packet core (EPC), and the core network may comprise a mobility management entity (MME) and a gateway node. The MME may handle mobility of terminal devices in a tracking area encompassing a plurality of cells and handle signalling connections between the terminal devices and the core network. The gateway node may handle data routing in the core network and to/from the terminal devices. The 5G specifications specify the core network as a 5G core (5GC), and there the core network may comprise e.g. an access and mobility management function (AMF) and a user plane function/gateway (UPF), to mention only a few. The AMF may handle termination of non-access stratum (NAS) signalling, NAS ciphering & integrity protection, registration management, connection management, mobility management, access authentication and authorization, security context management. The UPF node may support packet routing & forwarding, packet inspection and QoS handling, for example.

For the purposes of discussion, “a/the first radio access technology” described herein is 5G, “a/the second radio access technology” is 6G and “a/the third radio access technology” is 4G. However, it should be understood that the invention is not limited to these radio access technologies (RATs) and could use any former or future radio access technologies. Likewise, “first network node” or “first base station” refers herein to a 5G gNB configured in operation to provide access to a 5G network and “second network node” or “second base station” refers to a 4G eNB configured to provide access to a 4G (LTE) network. The network nodes or base stations described could also be used to provide access to any former or future RAT.

As previously described, with reference to Figures 1 and 2, the method used for a non- standalone (NS A) solution for migration of 4G to 5G would not be practical for migration of 5G to 6G, although a NSA solution for migration of 5G to 6G will be needed before migration to full SA 6G. The 6G SA network architecture is not yet known but it will need to be compatible with the NSA architecture. In 6G the final architecture may be utilizing e.g. Service-Based Architecture (SBA) that could require different network interfaces, or include converged core/RAN functionalities (e.g. combined CU/DU, which could be similar to 4G eNB). Therefore it is possible that current NG type of interface does not exist in 6G. If 5G/6G NSA migration were to use the 4G/5G approach shown in Figures 1 and 2, it could lead to major differences in NSA based solution and final SA based solution. This would either limit final 6G architecture options or would need completely different types of products for NSA and SA options.

Figure 4 shows an embodiment in which an apparatus 130 is a 6G non- standalone (NSA) device embodied in the distributed unit (DU) of a 5G gNB 110, which provides a UE 120 with access to the 3GPP RAN network 100. The gNB 110 may be connected to another gNB 112 via an Xn-C interface but in one embodiment the Xn-C interface is not required. The gNBs 110 and 112 can each be connected to the 5G core network (5GC) 116 via a NG interface and are also referred to herein as network nodes, network access nodes or base stations.

Figure 4 also shows the overall 5G architecture where the gNB 110 is split into the gNB Central Unit (gNB-CU) 117 and two gNB distributed units (gNB-DU) 118 and 130. In 5G the gNB- CU is also futher split to gNB-CU-U and gNB-CU-C. This split architecture allows the implementation to change for one component without the need to reimplement other components if the interface changes are kept to a minimum. Thus, in a minimal migration to 6G shown in this embodiment only one gNB-DU 130 is replaced with a 6G equivalent DU. The 6gNB-DU 130 is configured by 0AM and in an Fl -operational state. A setup over the Fl interface towards the 5G gNB- CU 117 is performed, which allows a 6G radio entity connectivity to a 5G core network. In other words, although the base station 110 is configured for access to a 5G network, it can provide access on the radio interface to a 6G UE 120 via the device 130.

Figure 5 shows an example method performed in one embodiment by the apparatus 130. The method can be computer implemented. The method may be performed by a processor and by a memory storing computer program code that is run by the processor.

In step S210, the device or apparatus 130 sends a notification using a 5G to the UE 120 that the apparatus 130 is configured to use 6G. The apparatus 130 also notifies the UE 130 that the gNB 110 is configured to use 5G. This tells the UE 120 that although the gNB 110 is configured for access to a 5G network, the UE 120 can still access that network on the radio interface using 6G.

In step S211 the apparatus 130 receives a message from the user equipment 120 using 6G radio access technology that the user equipment is capable of using the 6G. When the UE 120 is looking for network access using 6G, the gNB 110 will be visible to it as giving 6G radio access, even though the gNB 110 is itself a 5G eNB.

In step 212, the apparatus 130 forwards the parameters required for access to 6G to the CU 117 of the gNB 110 and then in step 213 the apparatus 130 receives a configuration for 6G from the central unit 117 based on the parameters it forwarded to the CU 117.

In step 214 the apparatus 130 forwards the 6G configuration to the UE 120 using one or more higher layers of 5G. By “higher layers” it is meant higher than layer 2, so the RLC or PDCP layers, for example, or higher layer protocols such as F1AP, E1AP, NGAP, PDCP-C, NAS- MM, NAS-SM. However, this list is not exhaustive.

The initial setup of the method according to Figure 5 requires than the RAN network 100 integrates the device 130 (a radio unit with a 6G capability) to a gNB-DU so that it becomes a type of 6G radio access node in a 5G network access node.

In this way, the 6G radio frequency band (6-20GHz) becomes operational for the gNB 110, or the network node 110 operates on frequencies using MRSS with 6G specific spectrum. The apparatus 130 is a radio node with 6G radio capabilities that becomes anchored in a legacy Core Network (4G or 5G). For example, a 5G gNB-DU can become upgraded to a 6G gNB- DU and reconfigured by a 5gNB-CU via Fl message gNB-DU Resource Coordination with 6G specific resources.

In one embodiment, the apparatus 130 could be a new 6G radio unit, which can be set up through a Fl Setup message to the 5gNB-CU 117 with its 6G status indication.

This initial setup on the network side needs to become detectable by the UEs. For this purpose, after successful setup of the 6gNB-DU unit as the apparatus 130. the neighbouring 5G radio units, in this example gNB 112 notify the users in their range about the 6gNB-DU availability. The 5G gNB 112 and other neighbouring network nodes can provide information about 6G capabilities of the gNB 110, for example frequency. Alternatively, the apparatus 130 can broadcast information itself to notify the UE 120 of its 6G capabilities. In the initial phases of 5G to 6G migration, the System Information can be signalled according to a 5G format with a new 6G radio frequency band (6-20GHz) or the information can be provided that the network node 110 with the apparatus 130 is capable of operating on frequencies using MRSS with a 6G specific spectrum.

A message flow diagram illustrating an embodiment of the invention is shown in Figure 6.

The UE 120, being in a range of the 6G network, after detection of the network can detect the 6gNB-DU radio and synchronize with it. Detection of the network with 6G capabilities may result in a 6G indication/6G identifier/6G icon by the UE 120, implying a state in which the UE 120 becomes in a range of a 6G specific PLMN/frequency band or spectrum available for 6G operations.

For the initial radio connection, without requirement to use Xn interface, pure establishment of the connection may be split into the following steps:

1. UE initiates 5G RRC setup to 6G radio a. RRCSetupRequest is build according to 5G RRC protocol syntax (enabling 5G UEs to benefit from 6G radio) b. RRCSetupRequest may indicate 6G UE capability (e.g. 6G UE identity is mapped to 5G RRC Setup Request message or the UE indicates 6g specific establishment cause)

2. 6G DU decodes the 5G RRC setup request message, build needed 6G configuration and sends the message to 5G gNB-CU. As the RRC configuration from DU is transparent for the gNB-CU, the gNB-CU handles the initial UL RRC message similar than if the message would come from 5G DU.

3. gNB-CU delivers 6G configuration in 5G RRCsetup message to DU

4. the 6G DU delivers the RRC setup to the UE

5. The UE setup 6G SRB signalling radio bearer UE configures 6G configuration to use and continues signaling like in 5G

6-18. No changes to 5G The principle behind all the embodiments is that the UE 120 uses its existing 5G RRC signalling with a 6G RRC container.

The 6G RRC configuration can be encapsulated in the 5G CellGroupConfig, which allows the current 5G RRC to be reused, as shown below:

A method according to one embodiment is shown in Figure 7 from the point of view of the UE 120.

In step S310, the UE 120 receives a notification using the 5G from the apparatus 130 in the gNB 110 the gNB 110 is capable of providing network access using 6G (via the device 130 embodied in a DU of the gNB 110). In step S311 , the UE 120 then sends a message using 6G to the gNB 110 that the UE 120 is capable of operating using 6G. In step S312, the gNB 110 then sends a configuration for 6G using higher layers of 5G. By “higher layers” it is meant higher than layer 2, so the RLC or PDCP layers, for example, or higher layer protocols such as F1AP, E1AP, NGAP, PDCP-C, NAS-MM, NAS-SM. However, this list is not exhaustive. Using the configuration, in step S313, the UE 120 is then configured for the 6G and sets up a 6G signalling radio bearer between the UE 120 and the gNB 110 (via the device 130).

In a further embodiment, which could be a subsequent migration step, the gNB-CU-U is also replaced with 6G equalent U-plane and integrate more 6G specific operations (for instance terminating and decoding RRC messages).

For example, in an embodiment shown in Figure 8, an apparatus or device 131 in the gNB 110 is configured for providing 6G access to the network node gNB 110, even though the gNB 110 is configured for accessing a 5G network. The device 131 provides the same functionality as the device 130 shown in Figure 4. However, in this case the device 131 performs the functions of both the DU and the CU of the gNB 110 so that it is interfaced with the 5G core network (5GC) 116 and provides a radio interface to the UE 120. The device 131 is configured to perform the method shown in Figure 9. The method may be computer implemented and can be performed by at least one memory including computer program code and a processor.

In step S410, the apparatus 131 sends a notification in using 5G to the user equipment 120 that the apparatus 131 is configured to use 6G, and that the network node gNB 110 is configured to access a network using 5G. In step S411, the apparatus 131 receives a message using 6G from the user equipment that the user equipment is capable of operating using 6G. In step 412, the apparatus 131 forwards parameters required for access to 6G to the 5G network. In step S413, the apparatus 131 receives a 6G configuration from the network (the 5G core network 116) based on the parameters received by the network in step S412 and sends the 6G configuration to the UE 120 using higher layers of the 5G network. By “higher layers” it is meant that the 6G configuration is sent using 5G protocol layers higher than layer 2, so the RLC or PDCP layers, for example, or higher layer protocols such as F1AP, E1AP, NGAP, PDCP-C, NAS-MM, NAS-SM. However, this list is not exhaustive.

Both methods depicted in Figure 4 and Figure 9, performed by devices 130 and 131, respectively allow the UE 120 to have a standalone (SA) 6G connection to a non- standalone (NS A) network using 5G gNB higher layers and/or a 5G core network. In other words, the NSA network may then be a combination of 6G radio and 5G higher layers. By “higher layers” it is meant higher than layer 2, so the REC or PDCP layers, for example, or higher layer protocols such as F1AP, E1AP, NGAP, PDCP-C, NAS-MM, NAS-SM. However, this list is not exhaustive

The embodiments described herein provide the advantage that radio splitting is not required, compared to the 4G/5G migration solution shown in Figure 1, where the UE needs to split the radio.

In a further embodiment shown in Figure 10, a 4G eNB 210 may be added to the network as a second network node, interfaced to the gNB 110 over X2-C interface. The method for this embodiment, is the same as that shown in Figures 4 and 9, with the additional steps shown in Figure 11. In Step 420, the apparatus 130 receives an addition request from the 4G eNB 210 to add the apparatus 130 using 6G to a 4G network.

In Step 421 the gNB 110 sends a request using 5G to the device 130 for a 6G configuration in response to receiving the addition request from the eNB 210.

In Step 422 the device 130 sends a configuration for 6G to the gNB 110 using 5G.

In step 423 the gNB 110 sends the configuration for 6G to the eNB 210 using 4G for configuring the user equipment 120 to access 6G via the device 130. In this way, the 6G UE 120 can have network access via the 4G eNB 210.

A message flow diagram for the embodiments shown in Figures 10 and 11 is shown in Figure 12.

1. ETE/4G eNB 210 makes a decision to add a 6G UE 120 that is connected to the 5G gNB 110 via the apparatus 130 and sends SgNB Addition Request.

2. gNB-CU 117 requests a 6G configurtation from 6G device 130 with a UE Context Setup Request

3. 6G device 130 responds to the configuration request with UE Context Setup Response

4. LTE/4G eNB 210 delivers the 6G configuration to the UE 120 with a 4G RRCConnectionReconfiguration mes sage .

5-12. No changes to existing functionality

As in the other embodiments, the 6G RRC configuration can be encapsulated in the 5G CellGroupConfig, which allows the current 5G RRC to be reused.

In an embodiment, the UE 120 may comprise the terminal device of a communication system, e.g. a user terminal (UT), a computer (PC), a laptop, a tabloid computer, a cellular phone, a mobile phone, a communicator, a smart phone, a palm computer, a mobile transportation apparatus (such as a car), a household appliance, or any other communication apparatus, commonly called as UE in the description. Alternatively, the apparatus is comprised in such a terminal device. Further, the apparatus may be or comprise a module (to be attached to the UE) providing connectivity, such as a plug-in unit, an “USB dongle”, or any other kind of unit. The unit may be installed either inside the UE or attached to the UE with a connector or even wirelessly.

In an embodiment shown in Figure 13, the circuitry in the UE 120 is shown. The UE 120 may be caused to execute some of the functionalities of the above described processes, such as the steps shown in Figure 7.

The UE 120 may further comprise a radio interface (TRX) 16 comprising hardware and/or software for realizing communication connectivity according to one or more communication protocols. The TRX may provide the apparatus with communication capabilities to access the radio access network, for example.

The apparatus may also comprise a user interface 18 comprising, for example, at least one keypad, a microphone, a touch display, a display, a speaker, etc. The user interface may be used to control the apparatus by the user.

The control circuitry 12 may comprise relevant circuitry/ies 20 for performing the functions, according to any of the embodiments.

An embodiment, as shown in Figure 14, provides an apparatus 130 (and may also apply to the apparatus 131) comprising a control circuitry (CTRL) 52, such as at least one processor, and at least one memory 54 storing instructions that, when executed by the at least one processor, cause the apparatus at least to carry out any one of the above-described processes. In an example, the at least one memory and the computer program code (software), are configured, with the at least one processor, to cause the apparatus to carry out any one of the abovedescribed processes. The memory 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 removable memory. The memory may comprise a database for storing data.

In an embodiment, the apparatus 130 may be or be comprised in a network node, such as in gNB/gNB-CU/gNB-DU of 5G. In an embodiment, the apparatus is or is comprised in the network node 110. The apparatus may be caused to execute some of the functionalities of the above described processes, such as the steps of Figures 5, 9 or 11.

The apparatus may further comprise communication interface (TRX) 56 comprising hardware and/or software for realizing communication connectivity according to one or more communication protocols. The TRX may provide the apparatus with communication capabilities with at least one user equipment, for example.

The apparatus may also comprise a user interface 58 comprising, for example, at least one keypad, a microphone, a touch display, a display, a speaker, etc. The user interface may be used to control the apparatus by the user. The control circuitry 52 may comprise a circuitry 60 for carrying out the method steps according to any of the embodiments described herein.

In an embodiment, a CU-DU (central unit - distributed unit) architecture is implemented. In such case the apparatus 50 may be comprised in a central unit (e.g. a control unit, an edge cloud server, a server) operatively coupled (e.g. via a wireless or wired network) to a distributed unit (e.g. a remote radio head/node). That is, the central unit (e.g. an edge cloud server) and the radio node may be stand-alone apparatuses communicating with each other via a radio path or via a wired connection. Alternatively, they may be in a same entity communicating via a wired connection, etc. The edge cloud or edge cloud server may serve a plurality of radio nodes or a radio access networks. In an embodiment, at least some of the described processes may be performed by the central unit. In another embodiment, the apparatus may be instead comprised in the distributed unit, and at least some of the described processes may be performed by the distributed unit. In an embodiment, the execution of at least some of the functionalities of the apparatus 130 or 131 may be shared between two physically separate devices (DU and CU) forming one operational entity. Therefore, the apparatus may be seen to depict the operational entity comprising one or more physically separate devices for executing at least some of the described processes. In an embodiment, the apparatus controls the execution of the processes, regardless of the location of the apparatus and regardless of where the processes/functions are carried out.

In an embodiment, an apparatus carrying out at least some of the embodiments described comprises at least one processor and at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus to carry out the functionalities according to any one of the embodiments described. According to an aspect, when the at least one processor executes the computer program code, the computer program code causes the apparatus to carry out the functionalities according to any one of the embodiments described. According to another embodiment, the apparatus carrying out at least some of the embodiments comprises the at least one processor and at least one memory including a computer program code, wherein the at least one processor and the computer program code perform at least some of the functionalities according to any one of the embodiments described. Accordingly, the at least one processor, the memory, and the computer program code form processing means for carrying out at least some of the embodiments described. According to yet another embodiment, the apparatus carrying out at least some of the embodiments comprises a circuitry including at least one processor and at least one memory including computer program code. When activated, the circuitry causes the apparatus to perform the at least some of the functionalities according to any one of the embodiments described.

As used in this application, the term ‘circuitry’ refers to all of the following: (a) hardware- only circuit implementations, such as implementations in only analog and/or digital circuitry, and (b) combinations of circuits and soft- ware (and/or firmware), such as (as applicable): (i) a combination of processor(s) or (ii) portions of processor(s)/software including digital signal processor(s), software, and memory (ies) that work together to cause an apparatus to perform various functions, and (c) circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present. This definition of ‘circuitry’ applies to all uses of this term in this application. As a further example, as used in this application, the term ‘circuitry’ would also cover an implementation of merely a processor (or multiple processors) or a portion of a processor and its (or their) accompanying software and/or firmware. The term ‘circuitry’ would also cover, for example and if applicable to the particular element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in a server, a cellular network device, or another network device.

In an embodiment, at least some of the processes described may be carried out by an apparatus comprising corresponding means for carrying out at least some of the described processes. Some example means for carrying out the processes may include at least one of the following: detector, processor (including dual-core and multiple-core processors), digital signal processor, controller, receiver, transmitter, encoder, decoder, memory, RAM, ROM, software, firmware, display, user interface, display circuitry, user interface circuitry, user interface software, display software, circuit, antenna, antenna circuitry, and circuitry.

A 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).

As used herein the term “means” is to be construed in singular form, i.e. referring to a single element, or in plural form, i.e. referring to a combination of single elements. Therefore, terminology “means for [performing A, B, C]”, is to be interpreted to cover an apparatus in T1 which there is only one means for performing A, B and C, or where there are separate means for performing A, B and C, or partially or fully overlapping means for performing A, B, C. Further, terminology “means for performing A, means for performing B, means for performing C” is to be interpreted to cover an apparatus in which there is only one means for performing A, B and C, or where there are separate means for performing A, B and C, or partially or fully overlapping means for performing A, B, C.

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 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), 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 chip set (e.g. 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.

Embodiments as described may also be carried out in the form of a computer process defined by a computer program or portions thereof. Embodiments of the methods described may be carried out by executing at least one portion of a computer program comprising corresponding instructions. The computer program may be in source code form, object code form, or in some intermediate form, and it may be stored in some sort of carrier, which may be any entity or device capable of carrying the program. For example, the computer program may be stored on a computer program distribution medium readable by a computer or a processor. The computer program medium may be, for example but not limited to, a record medium, computer memory, read-only memory, electrical carrier signal, telecommunications signal, and software distribution package, for example. The computer program medium may be a non-transitory medium. Coding of software for carrying out the embodiments as shown and described is well within the scope of a person of ordinary skill in the art.

Although the invention has been described above with reference to examples according to the accompanying drawings, it is clear that the invention is not restricted thereto but can be modified in several ways within the scope of the appended claims. Therefore, all words and expressions should be interpreted broadly and they are intended to illustrate, not to restrict, the embodiment. It will be obvious to a person skilled in the art that, as technology advances, the inventive concept can be implemented in various ways. Further, it is clear to a person skilled in the art that the described embodiments may, but are not required to, be combined with other embodiments in various ways.

Claims

1. A device for a network node, the device comprising: at least one processor, and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the device at least to: send a notification using a first radio access technology to a user equipment that the device is configured to use a second radio access technology and that the network node is configured to use the first radio access technology, receive a message from the user equipment using the second radio access technology that the user equipment is capable of using the second radio access technology, forward parameters required for access to the second radio access technology to a central unit of the network node configured for the first radio access technology, receive a configuration for the second radio access technology from the central unit based on said parameters, and send the configuration for the second radio access technology to the user equipment using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2.

2. The device according to claim 1, wherein the device is a non-standalone, NS A, radio device.

3. The device according to claim 1 or claim 2, wherein the configuration for the second radio access technology is sent to the user equipment using the third and/or higher layers of the first radio access technology.

4. The device according to any of claims 1 to 3, wherein the device is configured for incorporation into a core network part of a network.

5. The device according to any of claims 1 to 4, wherein the device is connectable to the core network of the first radio access technology via an interface.

6. The device according to any of claims 1 to 5, wherein the first radio access technology is 5G and the second radio access technology is a future radio access technology.

7. The device according to claim 6, wherein the future radio access technology is 6G.

8. An apparatus for a network node, comprising: means for sending a notification using a first radio access technology to a user equipment that the apparatus is configured to use a second radio access technology, and that the network node is configured to use the first radio access technology, means for receiving a message using the second radio access technology from the user equipment that the user equipment is capable of using the second radio access technology, means for forwarding parameters required for access to the second radio access technology to a central unit of the network node configured for the first radio access technology, means for receiving a configuration for the second radio access technology from the central unit based on said parameters, and means for sending the configuration for the second radio access technology to the user equipment using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2.

9. A device for a network node, the device comprising: at least one processor; and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the device at least to send a notification in a first radio access technology to a user equipment that the device is configured to use a second radio access technology, and that the network node is configured to access a network using the first radio access technology, receive a message using the second radio access technology from the user equipment that the user equipment is capable of operating using the second radio access technology, forward parameters required for access to the second radio access technology to the network using the first radio technology, receive a configuration from the network for the second radio access technology based on said parameters, and send the configuration for the second radio access technology to the user equipment using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2.

10. A network node, comprising: a central unit configured for a first radio access technology; a first distributed unit configured for the first radio access technology and connected to the central unit; and a second distributed unit connected to the central unit and configured for a second radio access technology, wherein the second distributed unit comprises a transmitter configured to send a notification in the first radio access technology to a user equipment that the network node is configured to access a network using the first radio access technology and the second distributed unit is configured to operate using a second radio access technology, a receiver configured to receive a message using the second radio access technology from the user equipment that the user equipment is capable of operating using the second radio access technology, a processor configured to forward parameters required for access to the second radio access technology to the central unit, wherein the processor is further configured to receive a configuration for the second radio access technology from the central unit based on said parameters, and the transmitter is further configured to send the configuration for the second radio access technology to the user equipment using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2.

11. A network node, comprising: a central unit configured for a first radio access technology; and a radio device configured for a second radio access technology, wherein the radio device comprises at least one processor, and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the radio device at least to: send a notification using the first radio access technology to a user equipment of a capability of the radio device to operate using a second radio access technology, receive a message using the second radio access technology from the user equipment that the user equipment is capable of operating using the second radio access technology, forward parameters required for access to the second radio access technology to the central unit of the network node configured for the first radio access technology, receive a configuration for the second radio access technology from the central unit based on said parameters, and send the configuration for the second radio access technology to the user equipment using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2.

12. The network node according to claim 11, wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the network node at least to: receive an addition request from a second network node configured for a third radio access technology to add the radio device using the second radio access technology to a network using the third radio access technology, send a request using the first radio access technology to the radio device for a configuration for the second radio access technology in response to receiving the addition request, receive a configuration for the second network access technology using the first radio access technology, send the configuration for the second radio access technology to the second network node for configuring the user equipment using the third radio access technology to access the second radio access technology.

13. The network node according to claim 11 or claim 12, wherein the message is a RRC set up request message.

14. A user equipment for operation in at least a first radio access technology and a second radio access technology, the user equipment comprising: at least one processor, and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the user equipment at least to: receive a notification using the first radio access technology from a network node configured for the first radio technology that the network node is capable of providing network access using the second radio technology, send a message using the second radio access technology to the network node that the user equipment is capable of operating using the second radio access technology, receive a configuration for the second radio access technology from the network node using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2, and configure the user equipment for the second radio access technology and set up a signalling radio bearer for the second radio access technology between the user equipment and the network node using the configuration.

15. An apparatus, comprising: means for receiving a notification using a first radio access technology from a network node configured for the first radio technology that the network node is capable of providing network access using a second radio technology, means for sending an indication using the second radio access technology to the network node that the apparatus is capable of operating using the second radio access technology, means for receiving a configuration for the second radio access technology from the network node using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2, and means for configuring the apparatus for the second radio access technology and setting up a signalling radio bearer for the second radio access technology between the apparatus and the network node using the configuration.

16. A method, comprising: sending a notification in a first radio access technology from a network node to a user equipment of a capability of the network node to provide network access in a second radio access technology; receiving a message using the second radio access technology from the user equipment that the user equipment is capable of operating using the second radio access technology; forwarding parameters required for access to the second radio access technology to a central unit of the network node configured for the first radio access technology; receiving a configuration for the second radio access technology from the central unit based on said parameters, and sending the configuration for the second radio access technology to the user equipment using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2.

17. The method according to claim 16, wherein the message is a RRC setup request message.

18. The method according to claim 16 or claim 17, wherein the parameters are forwarded using initial uplink RRC message transfer.

19. The method according to any of claims 16 to 18, wherein the configuration is received using downlink RRC message transfer.

20. The method according to any of claims 16 to 19, wherein the configuration for the second radio access technology is sent to the user equipment by piggybacking on a RRC connection using the first radio access technology.

21. The method according to claim 20, wherein an RRC configuration for the second radio access technology is encapsulated in a CellGroupConfig of the first radio access technology.

22. The method according to any of claims 16 to 21, further comprising receiving a request from a second network node requesting to connect to the network node using a third radio access technology, requesting a configuration for the second network node using the third radio access technology, receiving the configuration for the second network node, forwarding the configuration for the second network node to the central unit of the network node using the second radio access technology, receiving a message from a user equipment indicating a capability of the user equipment to operate in the second radio access technology, forwarding capability parameters required for access to the second radio access network from the user equipment to the second network node, receiving a configuration at the second network node for the second radio access technology based on said capability parameters, and sending the configuration for the second radio access technology to the user equipment using the third radio access technology.

23. The method according to claim 22, wherein the first radio access technology is 5G, the second radio technology is 6G and the third radio access technology is 4G.

24. The method according to claim 22 or claim 23, wherein the first network node is a gNB configured for 5G network access and the second network node is an eNB configured for 4G network access.

25. A method, comprising: receiving a notification at a user equipment using a first radio access technology from a network node configured for the first radio technology that the network node is capable of providing network access using the second radio technology, sending a message using the second radio access technology to the network node that the user equipment is capable of operating using the second radio access technology, receiving a configuration for the second radio access technology from the network node using at least one layer of the first radio access technology, wherein the at least one layer is higher than Layer 2, and configuring the user equipment for the second radio access technology and setting up a signalling radio bearer for the second radio access technology between the user equipment and the network node using the configuration.

26. A computer program product embodied on a distribution medium readable by a computer and comprising program instructions which, when the program is executed by an apparatus, cause the apparatus to carry out the method according to any of claims 16 to 25.

27. A computer program product comprising program instructions which, when the program is executed by an apparatus, cause the apparatus to carry out the method according to any of claims 16 to 25.

28. A computer system, comprising: one or more processors; at least one data storage, and one or more computer program instructions to be executed by the one or more processors in association with the at least one data storage for carrying out a method according to any of claims 16 to 25.