EP4666616A1 - Service based radio resource control for cloud native ran - Google Patents

Abstract

A method comprising receiving by a control-plane network entity a service request from a user equipment; examining whether to forward at least a part of the service request to another entity in a network; determining by the control-plane network entity available resources for processing the at least a part of the service request in the network, when the examining indicates the apparatus to forward at least a part of the service request to another entity in the network; selecting among the available resources another entity for configuring the requested service for the user equipment; and communicating with the selected entity to update context of the user equipment.

Description

SERVICE BASED RADIO RESOURCE CONTROL FOR CLOUD

NATIVE RAN

TECHNICAL FIELD

[0001] The present invention relates to service based radio resource control for cloud native random access node.

BACKGROUND

[0002] 5G specifications provide an option to split the internal structure of an access node gNodeB (gNB) into entities called CU (Central Unit) and one or more DUs (Distributed Unit), which are connected by an Fl interface. This kind of split gNB architecture allows distributed Radio Access Network (RAN) deployments (i.e. gNB CU-DU split) and disaggregation of certain RAN network elements. This has led to a Control plane (C-plane) of the radio resource control protocol (RRC) being anchored in CU (as in 4G), but with its functionalities, such as configuration management of the lower layers, being split between a CU and a DU.

[0003] In 5G, the C-plane functionality in such RAN split architecture is also split, with a Centralized Unit Control Plane (CU-CP), a Centralized Unit User Plane (CU-UP) and DU components all including C-plane functionalities. A problem with the CU-DU split is increased central processing unit (CPU) processing need and also high latency. Extra CPU processing comes as the C-plane functionality is split to multiple network entities/components. Any required configuration requires multiple and long message scenarios to be exchanged between CU-CP and DU, CU-UP and DU. This problem is common to all UE requests irrespective of the type of service the UE needs. When a network node or entity (e.g. CU-CP) is sending (or receiving) a message it needs to code (or decode) the message and deliver it further possibly using multiple protocol stacks. Whenever a network node/entity needs to stop running an algorithm and to send a message to another network entity that can continue the message processing, it needs extra CPU computation and also causes extra latency.

SUMMARY

[0004] Now, an improved method and technical equipment implementing the method has been invented, by which the above problems are alleviated. Various aspects include a method, an apparatus and a non-transitory computer readable medium comprising a computer program, or a signal stored therein, which are characterized by what is stated in the independent claims. Various details of the embodiments are disclosed in the dependent claims and in the corresponding images and description.

[0005] The scope of protection sought for various embodiments of the invention is set out by the independent claims. The 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 of the invention.

[0006] According to some embodiments a Control Plane architecture is provided, for example for service-based 5G (5^th generation) and/or 6G (6^th generation) cloud native RAN, in which the RRC protocol for a given UE can be flexibly terminated in any C-Plane network entity (e.g. CU or DU or partially in CU and DU) based on the actual service requested by the UE (e.g. latency targets) and based on the available resources (to balance latency and CPU processing). For simplicity, in this invention, we use the 5G terminology for the disaggregated RAN architecture (i.e. CU and DU), however it is noted that such terminology may differ in 5G/6G.

[0007] In accordance with an embodiment, a method is defined where in the 5G/6G RAN architecture, the C-plane related algorithms and the data storage used by these algorithms can be separated in different network entities. Any C-Plane network entity can be a remote unit hosting the RRC protocol of a given UE. All Network access components (centralized, distributed units) include C-Plane functionalities e.g. for different UEs. In the approach, basically the fixed RRC protocol location of 5G in the CU is replaced by logical functionalities. Placement of the logical C-plane functionalities may depend on the network deployment model and/or on the service level it provides.

[0008] On a high level any c-plane logical function comprises a set of protocol configurators, a protocol manager and a shared data layer (SDL), which stores and maintains UE context data. [0009] All the computing units handling the logical functions are assumed to belong to trusted sites having the needed level of security.

[0010] Each c-plane logical function may comprise a protocol configurator(s) and a protocol manager. Each protocol configurator knows how to configure resources for a certain protocol and it is also aware of the features the protocol supports. Protocol manager is the higher-level manager that keeps the consistency of the functionality, knows the protocol sets the different network components are allowed to configure and whereas the shared data layer is used to store the data. Anyone, having the keys to the shared data layer and for the UE may be able to access the UE context data. This may allow easy UE context switch from one computing unit to another computing unit. In case the computing node needs to communicate outside of trusted sites it may also use messages.

[0011] When the logical functionality is disaggregated from the state storage the logic comes stateless. This means that the logic in the computing unit performs a task and output for the task, stores the state to the SDL and forgets the state. In accordance with an embodiment, the UE context owner and the RRC entity of the UE are owned by the computing unit that have both an SDL key and also a UE key to the SDL. Whoever have the keys may be able to make RRC messaging for the UE, so the message building for one UE is not limited only for one owner. The actual protocol level RRC content can be defined by who have a licence to configure the protocol. In case there are multiple non-shared owners the content data may need to be collected from all owners.

[0012] The way how the network manages consistency of the UE context can be based on minimal stateful UE context. For example, the first RRC node that defines security keys keeps the ownership of the UE or let the UE request to keep the context. In accordance with an approach, this means that the control plane in this case is in a state where none of the nodes is in active mode and the network is waiting input from outside like from the UE. Hence, the network may e.g. configure the UE with periodical reports/inputs and lack of those means finally context removal from the network.

[0013] One benefit of this model may be that when one computing unit is an owner of multiple protocol layers the algorithms can be optimal and unnecessary protocol hops and wasted CPU resources can be avoided. Also when the architecture really needs disaggregation the configuration can be built on the flow model where one computing mode configures those protocol layers that it is allowed and can configure and then the next computing unit continues from that. This procedure removes request, acknowledgement, and configuration update type of configuration collection.

[0014] According to a first aspect, there is provided an apparatus comprising means for receiving by the apparatus a service request from a user equipment; means for examining whether to forward at least a part of the service request to another entity in a network; means for determining by the apparatus available resources in the network, when the examining indicates the apparatus to forward at least a part of the service request to another entity in the network; means for selecting among the available resources another entity for configuring the requested service for the user equipment; and means for communicating with the selected entity to update context of the user equipment.

[0015] An apparatus according to a second aspect comprises at least one processor and at least one memory, said at least one memory stored with computer program code thereon, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: receiving by the apparatus a service request from a user equipment; examining whether to forward at least a part of the service request to another entity in a network; determining by the apparatus available resources in the network, when the examining indicates the apparatus to forward at least a part of the service request to another entity in the network; selecting among the available resources another entity for configuring the requested service for the user equipment; and communicating with the selected entity to update context of the user equipment.

[0016] A method according to a third aspect comprises receiving by a control-plane network entity a service request from a user equipment; examining whether to forward at least a part of the service request to another entity in a network; determining by the control-plane network entity available resources in the network, when the examining indicates the apparatus to forward at least a part of the service request to another entity in the network; selecting among the available resources another entity for configuring the requested service for the user equipment; and communicating with the selected entity to update context of the user equipment.

[0017] Computer readable storage media according to further aspects comprise code for use by an apparatus, which when executed by a processor, causes the apparatus to perform the above methods.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] For a more complete understanding of the example embodiments, reference is now made to the following descriptions taken in connection with the accompanying drawings in which:

[0019] Fig. 1 illustrates an example block diagram of a system, according to an embodiment; [0020] Fig. 2 illustrates overview on the 5G deployment model for the split gNB;

[0021]

[0022] Fig. 3 shows a part of an exemplifying radio access network;

[0023] Fig. 4 shows a method according to an embodiment;

[0024] Fig. 5 shows an example of a scalable and service based RAN architecture with remote extensions;

[0025] Fig. 6a shows an example of gNB logical functionalities in a non-distributed c-plane architecture;

[0026] Fig. 6b shows gNB logical functionalities in a distributed c-plane architecture according to an embodiment;

[0027] Figs. 7a, 7b and 7c illustrate a scalable network architecture with flowing configuration building according to an embodiment; and

[0028] Fig. 8 shows how UE context sharing can be implemented using a shared data layer, in accordance with an embodiment.

DETAILED DESCRIPTON OF SOME EXAMPLE EMBODIMENTS

[0029] The following describes in further detail suitable apparatus and possible mechanisms for carrying out the interface setup procedures involving Near-RT RICs. While the following focuses on 5G and/or 6G networks, the embodiments as described further below are by no means limited to be implemented in said networks only, but they are applicable in any network and protocol entities supporting the interfaces of the Near-RT RICs or equivalent entities.

[0030] In this regard, reference is first made to Figs. 1 and 2, where Fig. 1 shows a schematic block diagram of an exemplary apparatus or electronic device 50 usable in 5G and/or 6G networks.

[0031] Fig. 1 illustrates an example of a system that includes an apparatus 10, according to an embodiment. In an embodiment, apparatus 10 may be a node, host, or server in a communications network or serving such a network. For example, apparatus 10 may be a network node, satellite, base station, a Node B, an evolved Node B (eNB), 5G Node B or access point, next generation Node B (NG-NB or gNB), TRP, HAPS, integrated access and backhaul (IAB) node, and/or a WLAN access point, associated with a radio access network, such as a LTE network, 5G or NR. In some example embodiments, apparatus 10 may be gNB or other similar radio node, for instance.

[0032] It should be understood that, in some example embodiments, apparatus 10 may include an edge cloud server as a distributed computing system where the server and the radio node may be stand-alone apparatuses communicating with each other via a radio path or via a wired connection, or they may be located in a same entity communicating via a wired connection. For instance, in certain example embodiments where apparatus 10 represents a gNB, it may be configured in a central unit (CU) and distributed unit (DU) architecture that divides the gNB functionality. In such an architecture, the CU may be a logical node that includes gNB functions such as transfer of user data, mobility control, radio access network sharing, positioning, and/or session management, etc. The CU may control the operation of DU(s) over a mid-haul interface, referred to as an Fl interface, and the DU(s) may have one or more radio unit (RU) connected with the DU(s) over a front-haul interface. The DU may be a logical node that includes a subset of the gNB functions, depending on the functional split option. It should be noted that one of ordinary skill in the art would understand that apparatus 10 may include components or features not shown in Fig. 1.

[0033] As illustrated in the example of Fig. 1, apparatus 10 may include a processor 12 for processing information and executing instructions or operations. Processor 12 may be any type of general or specific purpose processor. In fact, processor 12 may include one or more of general- purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), and processors based on a multi-core processor architecture, or any other processing means, as examples. While a single processor 12 is shown in Fig. 1, multiple processors may be utilized according to other embodiments. For example, it should be understood that, in certain embodiments, apparatus 10 may include two or more processors that may form a multiprocessor system (e.g., in this case processor 12 may represent a multiprocessor) that may support multiprocessing. In certain embodiments, the multiprocessor system may be tightly coupled or loosely coupled (e.g., to form a computer cluster).

[0034] Processor 12 may perform functions associated with the operation of apparatus 10, which may include, for example, precoding of antenna gain/phase parameters, encoding and decoding of individual bits forming a communication message, formatting of information, and overall control of the apparatus 10, including processes related to static reporting by a user equipment of maximum sensitivity degradation and relaxation values thereof based on specific network configurations and caapabilities of the user equipment.

[0035] Apparatus 10 may further include or be coupled to a memory 14 (internal or external), which may be coupled to processor 12, for storing information and instructions that may be executed by processor 12. Memory 14 may be one or more memories and of any type suitable to the local application environment, and may be implemented using any suitable volatile or nonvolatile data storage technology such as a semiconductor-based memory device, a magnetic memory device and system, an optical memory device and system, fixed memory, and/or removable memory. For example, memory 14 can be include any combination of random access memory (RAM), read only memory (ROM), static storage such as a magnetic or optical disk, hard disk drive (HDD), or any other type of non-transitory machine or computer readable media, or other appropriate storing means. The instructions stored in memory 14 may include program instructions or computer program code that, when executed by processor 12, enable the apparatus 10 to perform tasks as described herein.

[0036] In an embodiment, apparatus 10 may further include or be coupled to (internal or external) a drive or port that is configured to accept and read an external computer readable storage medium, such as an optical disc, USB drive, flash drive, or any other storage medium. For example, the external computer readable storage medium may store a computer program or software for execution by processor 12 and/or apparatus 10.

[0037] In some embodiments, apparatus 10 may also include or be coupled to one or more antennas 15 for transmitting and receiving signals and/or data to and from apparatus 10. Apparatus 10 may further include or be coupled to a transceiver 18 configured to transmit and receive information. The transceiver 18 may include, for example, a plurality of radio interfaces that may be coupled to the antenna(s) 15, or may include any other appropriate transceiving means. The radio interfaces may correspond to a plurality of radio access technologies including one or more of global system for mobile communications (GSM), narrow band Internet of Things (NB-IoT), LTE, 5G, WLAN, Bluetooth (BT), Bluetooth Low Energy (BT-LE), near-field communication (NFC), radio frequency identifier (RFID), ultra wideband (UWB), MulteFire, and the like. The radio interface may include components, such as filters, converters (for example, digital-to-analog converters and the like), mappers, a Fast Fourier Transform (FFT) module, and the like, to generate symbols for a transmission via one or more downlinks and to receive symbols (via an uplink, for example).

[0038] As such, transceiver 18 may be configured to modulate information on to a carrier waveform for transmission by the antenna(s) 15 and demodulate information received via the antenna(s) 15 for further processing by other elements of apparatus 10. In other embodiments, transceiver 18 may be capable of transmitting and receiving signals or data directly. Additionally or alternatively, in some embodiments, apparatus 10 may include an input and/or output device (I/O device), or an input/output means.

[0039] In an embodiment, memory 14 may store software modules that provide functionality when executed by processor 12. The modules may include, for example, an operating system that provides operating system functionality for apparatus 10. The memory may also store one or more functional modules, such as an application or program, to provide additional functionality for apparatus 10. The components of apparatus 10 may be implemented in hardware, or as any suitable combination of hardware and software.

[0040] According to some embodiments, processor 12 and memory 14 may be included in or may form a part of processing circuitry/means or control circuitry/means. In addition, in some embodiments, transceiver 18 may be included in or may form a part of transceiver circuitry/means.

[0041] In the following, different exemplifying embodiments will be described using, as an example of an access architecture to which the embodiments may be applied, a radio access architecture based on Long Term Evolution Advanced (LTE Advanced, LTE-A) or new radio (NR, 5G), or beyond 5G, e.g., 6G, without restricting the embodiments to such an architecture, however. A person skilled in the art appreciates that the 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 are the universal mobile telecommunications system (UMTS) radio access network (UTRAN or E-UTRAN), long term evolution (LTE, the same as E-UTRA), wireless local area network (WLAN or WiFi), 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. [0042] Figure 3 depicts examples of simplified system architectures only showing some elements and functional entities, all being logical units, whose implementation may differ from what is shown. The connections shown in Fig. 3 are logical connections; the actual physical connections may be different. It is apparent to a person skilled in the art that the system typically comprises also other functions and structures than those shown in Fig. 3. The 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. [0043] The example of Fig. 3 shows a part of an exemplifying radio access network.

[0044] Figure 3 shows user devices 300 and 302 configured to be in a wireless connection on one or more communication channels in a cell with an access node (such as (e/g)NodeB or a base transceiver station (BTS)) 304 providing the cell. The physical link from a user device to a (e/g)NodeB is called uplink or reverse link and the physical link from the (e/g)NodeB to the user device is called downlink or forward link. It should be appreciated that (e/g)NodeBs or their functionalities may be implemented by using any node (such as Integrated Access and Backhaul (IAB) node), host, server or access point etc. entity suitable for such a usage.

[0045] A communication system typically comprises more than one (e/g)NodeB in which case the (e/g)NodeBs 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. The (e/g)NodeB is or comprises a computing device configured to control the radio resources of communication system it is coupled to. The NodeB may also be referred to as a base station, an access point, an access node or any other type of interfacing device including a relay station capable of operating in a wireless environment. The (e/g)NodeB includes or is coupled to transceivers. From the transceivers of the (e/g)NodeB, a connection is 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 (e/g)NodeB is further connected to core network 310 (CN or next generation core NGC). Depending on the system, the counterpart on the CN side can be a serving gateway (S-GW, routing and forwarding user data packets), packet data network gateway (P-GW), for providing connectivity of user devices (UEs) to external packet data networks, or mobile management entity (MME), etc. The CN may comprise network entities or nodes that may be referred to management entities. Examples of the network entities comprise at least an Access and Mobility Management Function (AMF). [0046] In 5G NR and 6G NR, the User Plane Function (UPF) may be used to separate the control plane (c-plane) and the user plane (u-plane) functions. Therein, the Packet Gateway (PGW) control and user plane functions may be decoupled, whereby the data forwarding component (PGW-U) may be decentralized, while the PGW-related signaling (PGW-C) may remain in the core. This allows packet processing and traffic aggregation to be performed closer to the network edge, increasing bandwidth efficiencies while reducing network.

[0047] The user device (also called a user equipment (UE), a user terminal, a terminal device, a wireless device, a mobile station (MS) etc.) illustrates one type of an apparatus to which resources on the air interface are allocated and assigned, and thus any feature described herein with a user device may be implemented with a corresponding network apparatus, such as a relay node, an eNB, and an gNB. An example of such a relay node is a layer 3 relay (self-backhauling relay) towards the base station.

[0048] The user device typically refers 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, and multimedia device. It should be appreciated that a user device may also be a nearly exclusive uplink only device, of which an example is 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 are provided with the ability to transfer data over a network without requiring human-to-human or human-to-computer interaction. Accordingly, the user device may be an loT-device. The user device may also utilize cloud. In some applications, a user device may comprise a small portable device with radio parts (such as a watch, earphones or eyeglasses) and the computation is carried out in the cloud. The user device (or in some embodiments a layer 3 relay node) is configured to perform one or more of user equipment functionalities. The user device may also be called a subscriber unit, mobile station, remote terminal, access terminal, user terminal or user equipment (UE) just to mention but a few names or apparatuses.

[0049] Various techniques described herein may also be applied to a cyber-physical 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 has inherent mobility, are a subcategory of cyber-physical systems. Examples of mobile physical systems include mobile robotics and electronics transported by humans or animals.

[0050] 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.

[0051] 5G mobile communications supports 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 is expected to have multiple radio interfaces, namely below 6GHz, cmWave and mmWave, and also capable of being integrated with existing legacy radio access technologies, such as the LTE. Integration with the LTE may be implemented, at least in the early phase, as a system, where macro coverage is provided by the LTE and 5G radio interface access comes from small cells by aggregation to the LTE. In other words, 5G is planned to support both inter-RAT (Radio Access Technology) operability (such as LTE-5G) and inter-RI operability (inter-radio interface operability, such as below 6GHz - cmWave, below 6GHz - cmWave - mmWave). One of the concepts considered to be used in 5G networks is network slicing in which multiple independent and dedicated virtual sub-networks (network instances) may be created within the same infrastructure to run services that have different requirements on latency, reliability, throughput and mobility.

[0052] The communication system is also able to communicate with other networks, such as a public switched telephone network or the Internet 312, 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. 3 by “cloud” 314). The communication system may also comprise a central control entity, or a like, providing facilities for networks of different operators to cooperate for example in spectrum sharing.

[0053] 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, radio unit (RU) or base station comprising radio parts. It is also possible that node operations will be distributed among a plurality of servers, nodes or hosts. Application of cloud RAN architecture enables RAN real time functions being carried out at the RAN side (e.g. in a distributed unit, DU) and non-real time functions being carried out in a centralized manner (e.g. in a centralized unit, CU 308).

[0054] 5G may also utilize non-terrestrial nodes 306, e.g. access nodes, to enhance or complement the coverage of 5G service, for example by providing backhauling, wireless access to wireless devices, service continuity for machine-to-machine (M2M) communication, service continuity for Internet of Things (loT) devices, service continuity for passengers on board of vehicles, ensuring service availability for critical communications and/or ensuring service availability for future railway/maritime/ aeronautical communications. The non-terrestrial nodes may have fixed positions with respect to the Earth surface or the non-terrestrial nodes may be mobile non-terrestrial nodes that may move with respect to the Earth surface. The non-terrestrial nodes may comprise satellites and/or HAPSs (High Altitude Platform Stations). 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 304 or by a gNB located on-ground or in a satellite.

[0055] A person skilled in the art appreciates 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 (e/g)NodeBs, the user device may have an access to a plurality of radio cells and the system may comprise also other apparatuses, such as physical layer relay nodes or other network elements, etc. At least one of the (e/g)NodeBs or may be a Home(e/g)nodeB. 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 are large cells, usually having a diameter of up to tens of kilometers, or smaller cells such as micro-, femto- or picocells. The (e/g)NodeBs 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 cells. Typically, in multilayer networks, one access node provides one kind of a cell or cells, and thus a plurality of (e/g)NodeBs are required to provide such a network structure. [0056] For fulfilling the need for improving the deployment and performance of communication systems, the concept of “plug-and-play” (e/g)NodeBs has been introduced. Typically, a network which is able to use “plug-and-play” (e/g)Node Bs, includes, in addition to Home (e/g)NodeBs (H(e/g)nodeBs), a home node B gateway, or HNB-GW (not shown in Fig. 1). A HNB Gateway (HNB-GW), which is typically installed within an operator’s network may aggregate traffic from a large number of HNBs back to a core network.

[0057] The Radio Resource Control (RRC) protocol is used in various wireless communication systems for defining the air interface between the UE and a base station, such as eNB/gNB. This protocol is specified by 3GPP in in TS 36.331 for LTE and in TS 38.331 for 5G. In terms of the RRC, the UE may operate in LTE and in 5 G in an idle mode or in a connected mode, wherein the radio resources available for the UE are dependent on the mode where the UE at present resides. In 5G, the UE may also operate in inactive mode. In the RRC idle mode, the UE has no connection for communication, but the UE is able to listen to page messages. In the RRC connected mode, the UE may operate in different states, such as RRC IDLE (idle state without RRC connection and UE-based mobility), RRC INACTIVE (idle state with partially stored RRC connection parameters and UE-based mobility), RRC CONNECTED (connected state where UE can communicate with the network and uses network-based mobility). The UE may communicate with the eNB/gNB via various logical channels like Broadcast Control Channel (BCCH), Paging Control Channel (PCCH), Common Control Channel (CCCH), Dedicated Control Channel (DCCH), Dedicated Traffic Channel (DTCH).

[0058] The transitions between the states are controlled by a state machine of the RRC. When the UE is powered up, it is in a disconnected mode/idle mode. The UE may transit to RRC connected mode with an initial attach or with a connection establishment. If there is no activity from the UE for a short time, eNB/gNB may suspend its session by moving to RRC Inactive and can resume its session by moving to RRC connected mode. The UE can move to the RRC idle mode from the RRC connected mode or from the RRC inactive mode.

[0059] The actual user and control data from network to the UEs is transmitted via downlink physical channels, which in 5G include Physical downlink control channel (PDCCH) which carries the necessary downlink control information (DCI), Physical Downlink Shared Channel (PDSCH), which carries the user data and system information for user, and Physical broadcast channel (PBCH), which carries the necessary system information to enable a UE to access the 5G network.

[0060] The user and control data from UE to the network is transmitted via uplink physical channels, which in 5G include Physical Uplink Control Channel (PUCCH), which is used for uplink control information including HARQ (Hybrid Automatic Repeat reQuest) feedback acknowledgments, scheduling request, and downlink channel-state information for link adaptation, Physical Uplink Shared Channel (PUSCH), which is used for uplink data transmission, and Physical Random Access Channel (PRACH), which is used by the UE to request connection setup referred to as random access.

[0061] 5G specifications provide an option to split the internal structure of a gNB into entities called CU (Central Unit) and one or more DUs (Distributed Unit), which are connected by a Fl interface, as specified in 3 GPP 38.473. The split may provide traffic aggregation in terms of one gNB CU serving a plurality of gNB DUs operating as the actual node points for the air interface. The gNB-CU may be further split to CU-CP (Control Plane) and CU-UP (User Plane) and El interface has been introduced between them. Information of available resources and load must be shared across these network entities to implement various RRM (Radio Resource Management) functionalities.

[0062] Fig. 2 provides a basic overview on the 5G deployment model for the split gNB. The gNB comprises a Centralized Unit (gNB-CU) and one or more Distributed Units (gNB-DUs) connected to the gNB-CU. gNB-CU is a logical node that includes the gNB functions like user data transfer, Mobility management, Radio access network sharing, Positioning, Session Management etc., except such functions, which are allocated exclusively to the gNB-DU. gNB- CU controls the operation of gNB-DUs over Fl interface.

[0063] According to some embodiments, setup and functions for C-plane distributed entities are provided. Fig. 5 shows an example of a flowing RRC configuration model with different level of disaggregation for RAN deployment and for the UE service.

[0064] In the example of Fig. 5 all network components are working in a trusted network. In this example all components have access to the UE context data. Each of the RAN c-plane components (Protocol manager) have possibility to configure for the UE that part of the configuration that they are owning. This split may depend on the UE service and also from a hard split resource model. The names DU, CU-CP and CU-UP of some of the entities of Fig. 5 are just used as an example. In a future RAN these entities may be any computing resources that have resources for c-plane and/or RRC and the split can be different but to illustrate functionality here the 5G type of split is used as an example. The central unit CU can be, for example, a data center location and the distributed unit DU is another resource, which may be geographically or logically closer to the UE. In here the names DU, CU-CP, CU-UP mean a group of configurator managers with different level of licences for protocol configurators.

[0065] Figs. 6a and 6b provide examples of some implementation alternatives and examples of possible computing resources. Typically in a data center there are multiple network elements using the same or similar HW in the data center. When gNB is deployed in this kind of place it may be more like a set of logical functions than hardware with dedicated tasks.

[0066] In this architecture option one gNB can have multiple c-plane entities. Each of them may be able to configure all u-plane protocol/and or c-plane layer or only a part of them. When the system is working on a stateless way there is actually no state connected to a hardware of an entity. When the gNB functionality is deployed in a stateless way, any hardware of an entity that have access to the UE data may be able to continue the UE configuration modification. So, the owner of the UE context can be defined as an owner of the database where the UE data is stored. Basically, any entity that have the shared data layer key and a user equipment key can start to modify the UE context data.

[0067] Those network entities which have a knowledge of the network features and remaining resources can configure the network resources. Some network resources may also be stored to the shared data layer whereas in some cases those network resources maybe so much latency critical that only that instance having the state in a real time memory can allocate those. This access may be called as network resource keys. Those keys may be resource or protocol specific.

[0068] The c-plane entity that have UE keys and network keys can configure the resources. If the c-plane entity does not have access for some resources, the request can be sent for a next entry for further processing or requested from the entity.

[0069] On a high level the c-plane logical functions comprise a set of protocol configurators, a protocol manager and the shared data layer (SDL) as is illustrated in Fig. 6b in an exemplary manner. All the computing units handling the logical functions belong to the trusted sites with needed level of security, which means they are part of the same security domain and can be trusted with the same set of security keys. [0070] Each of the protocol configurators knows how to configure resources for certain protocol and the protocol configurators are also aware of the features the protocol supports. Protocol manager is the higher-level manager that keeps the consistency of the functionality, knows the protocol sets the different network components are allowed to configure and where the SDL is used to store the data. The SDL is a shared data layer that can store the data and share it over multiple data servers. Once the data is updated to one SDL server the same data may be copied to other locations as well. This allows access to the same data from multiple different locations. Any network element or other apparatus supporting the system presented in this specification, needs to register to the SDL to gain access to the SDL. Upon successful registration, the network element receiving the security key to access SDL, such network element may access the UE context data if it has the keys to the SDL and keys for the UE. This may allow easy UE context switch from one computing unit to another computing unit. In case the computing node need to communicate outside of trusted sites it may also be performed using messages.

[0071] In accordance with an embodiment, a security key may be delivered via an operation, administration, and management (0AM) function to one or more (or even each) c-plane entities. Then the owner of the UE can share the rights to other c-plane entities. The owner of the UE is e.g. the first c-plane entity that makes the UE key.

[0072] When the logical functionality is disaggregated from the state storage the logic becomes stateless. This means that the logic in the computing unit may operate as follows: the logic performs a task, forms an output for the task, stores the state to the SDL and forgets the state. In this specification there is described an example where the UE context owner and the RRC entity of the UE is owned by the computing unit that have both the SDL key and also the UE key to the SDL. The SDL key can also be a network key in case the context data moves via messaging. Whoever have these keys may be able to make RRC messaging for the UE, so the message building for one UE is not limited only for one owner. The actual protocol level RRC content can be defined by who have licence to configure the protocol. In case there are multiple non shared owners the content data needs to be collected from all owners.

[0073] Figs. 7a, 7b and 7c illustrate a scalable network architecture with flowing configuration building, depending on the service level UE needs and disaggregation level. [0074] Applicability of the architecture to 5G network and coordination among network entities are shown, in accordance with an embodiment. Depending on a disaggregation level, the configuration is built with the assumption that each network element, taking part in a message transfer, can change the RRC configuration.

[0075] In the example of Fig. 7a, the DU, the CU-CP and the CU-UP are disaggregated.

[0076] The CU-CP selects 701 the CU-UP and the DU as a best bearer(s) candidate for the request. As all the bearer(s) are requested 702 from the CU-UP, the CU-CP can allow the CU-UP to deliver 703 the configured u-plane resources directly to a correct DU.

[0077] Once the DU has configured needed radio resources for the UE it can make the final RRC message and deliver it 704 for the UE. The UE receives RRC messages and responses with the RRC complete message 705. The C-plane in the DU is able to open the message and update the UE context data.

[0078] The DU delivers a response 706 (if not yet acknowledged) to the CU-UP e.g. with needed TNL address info.

[0079] The CU-UP delivers 707 the acknowledgement to the CU-CP as it knows that only the CU-CP have rights to send the response for the AMF.

[0080] In the example of Fig. 7b, the CU and DU are disaggregated.

[0081] In this case the CU have configuration right also for the CU-UP resources.

[0082] After the CU-UP resource configuration and DU selection, the CU sends a context modification request 711 to the selected DU.

[0083] Once the DU has configured needed radio resources for the UE it can make the final RRC message and deliver it 712 for the UE.

[0084] The UE receives RRC messages and delivers 713 the response to the DU, which delivers 714 the response to the CU.

[0085] In the example of Fig. 7c, there is a combined gNB.

[0086] In this example case the gNB have rights to configure all u-plane layers and c-plane resources for the request. Hence the first instance can configure the RRC message directly for the UE and deliver 721 it to the UE, wherein the UE delivers 722 the response to the gNB.

[0087] Fig. 8 shows how the UE context sharing can be implemented using shared data layer, in accordance with an embodiment. When the operator takes computing units into use it shall configure 801 what resources each node shall be able to configure and to what SDL pool they will belong. The RAN-DU knows its features and RRC rights. If a request exceeds, the capability request will be sent to a next layer or data will be requested from the next layer.

[0088] Each node shall get in this phase an SDL key that is a general key to the SDL. These steps are illustrated with the block 801 and arrows 802, 803, 804 and 805 in Fig. 8.

[0089] UE specific handling goes in the following way, in accordance with an embodiment. [0090] The gNb-DU receives new RRC setup request 806 without any keys. The gNB-DU then makes UE context and uses the SDL key and newly created UE key to secure 807 the UE data. The network is secured e.g. using encrypted messaging 808 and the DU makes an additional key that is used for UE context sharing. This may ensure that only the network entities for which the UE handling is given can modify the UE context.

[0091] The gNB-DU shall receive RRC setup complete with initial UE message 809 from the UE. In this case the gNB-DU identifies that CU also needs to handle the UE context wherein the gNB-DU shares 810 the UE context keys with the gNb-CU.

[0092] When the gNB-CU receives the UE context request 811 e.g. via the u-plane it can make a decision 812 where is the best place to handle the request or can any component that have the UE keys handle the UE context data. This request may also include a request that the CU comes as a master owner for the UE context. Basically, the owner of the UE can make the decision does it store (minimal) stateful UE data or does it completely work in a state manner and trust the UE as an owner of the UE context. In this case the network may request 813 the UE periodically to update a need to keep the context and define SDL to delete the context if time expires (e.g. a preset time related condition is fulfilled, such as the age of the UE context).

[0093] If the UE context continues in the shared mode, then the node receiving the message first may be able to proceed with the UE configuration.

[0094] In the following, an enhanced method for service based RRC for a cloud native RAN will be described, in accordance with an embodiment.

[0095] The method is disclosed in flow chart of Fig. 4 as reflecting the operation of an apparatus, such as a control-plane network entity , wherein the method comprises receiving 401 by a control-plane network entity a service request from a user equipment, examining 402 whether to forward at least a part of the service request to another entity in a network, determining 403 by the control-plane network entity available resources for processing the at least a part of the service request in the network, when the examining indicates the apparatus to forward at least a part of the service request to another entity in the network, selecting 404 among the available resources another entity for configuring the requested service for the user equipment, and communicating 405 with the selected entity to update context of the user equipment.

[0096] According to an embodiment, the method comprises storing and maintaining the user equipment data in a shared data layer.

[0097] According to an embodiment, the control-plane comprises a set of protocol configurators and a protocol manager.

[0098] According to an embodiment, the communicating comprises delivering a shared data layer key and a user equipment key to the selected entity.

[0099] According to an embodiment, the apparatus comprises means for delivering a security key via an operation, administration, and management function to one or more c-plane entities. [0100] According to an embodiment, the apparatus comprises means for sharing rights for context of the user equipment to the one or more c-plane entities.

[0101] According to an embodiment, said means for examining comprising at least one of the following: means for examining whether the apparatus has enough processing capability to handle the request, means for examining how much latency would result if the request were handled by the apparatus.

[0102] According to an embodiment, the apparatus comprises information of network features and remaining resources to determine whether the apparatus can configure network resources for the service request.

[0103] According to an embodiment, the apparatus is a part of a trusted site with level of security fulfilling a security requirement.

[0104] According to an embodiment, the apparatus comprises a set of protocol configurators, a protocol manager and a shared data layer.

[0105] According to an embodiment, the protocol configurators comprise means for configuring resources for certain protocol, wherein the protocol configurator is aware of features the protocol supports.

[0106] According to an embodiment, the protocol manager comprises means for keeping consistency of the functionality, wherein the protocol manager is aware of protocol sets the different network components are allowed to configure and where the SDL is used to store the data.

[0107] According to an embodiment, the shared data layer comprises means for storing data and share the data over multiple data servers.

[0108] The method and the embodiments related thereto may be implemented in an apparatus implementing functionalities of a near-real-time radio access network intelligent controller.

[0109] Such apparatuses may comprise e.g. the functional units disclosed in Figure 6 for implementing the embodiments.

[0110] A further aspect relates to a computer program product, stored on a non-transitory memory medium, comprising computer program code, which when executed by at least one processor, causes an apparatus at least to perform: receiving by the control-plane network entity a service request from a user equipment, determining by the control-plane network entity available resources in a network, selecting among the available resources an entity for configuring the requested service for the user equipment, and communicating with the selected entity to update context of the user equipment.

[0111] In general, the various embodiments of the invention may be implemented in hardware or special purpose circuits or any combination thereof. While various aspects of the invention may be illustrated and described as block diagrams or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0112] Embodiments of the inventions may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate. [0113] Programs, such as those provided by Synopsys, Inc. of Mountain View, California and Cadence Design, of San Jose, California automatically route conductors and locate components on a semiconductor chip using well established rules of design as well as libraries of pre stored design modules. Once the design for a semiconductor circuit has been completed, the resultant design, in a standardized electronic format (e.g., Opus, GDSII, or the like) may be transmitted to a semiconductor fabrication facility or "fab" for fabrication.

[0114] The foregoing description has provided by way of exemplary and non-limiting examples a full and informative description of the exemplary embodiment of this invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended examples. However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention.

Claims

1. An apparatus comprising: means for receiving by the apparatus a service request from a user equipment; means for examining whether to forward at least a part of the service request to another entity in a network; means for determining by the apparatus available resources for processing the at least a part of the service request in the network, when the examining indicates the apparatus to forward at least a part of the service request to another entity in the network; means for selecting among the available resources another entity for configuring the requested service for the user equipment; and means for communicating with the selected entity to update context of the user equipment.

2. The apparatus according to claim 1 comprising: means for delivering a security key via an operation, administration, and management function to one or more c-plane entities.

3. The apparatus according to claim 1 comprising: means for obtaining a security key by performing a registration procedure with a server hosting a shared data layer; and means for using the security key to access the shared data layer.

4. The apparatus according to claim 3 comprising: means for obtaining a user equipment key; and means for performing radio resource control messaging for the user equipment by using the security key and the user equipment key.

5. The apparatus according to any of the claims 1 to 4 comprising: means for sharing rights for context of the user equipment to the one or more c-plane entities.

6. The apparatus according to any of the claims 1 to 5, said means for examining comprising at least one of the following: means for examining whether the apparatus has enough processing capability to handle the request, means for examining how much latency would result if the request were handled by the apparatus.

7. The apparatus according to any of the claims 1 to 6 comprising: information of network features and remaining resources to determine whether the apparatus can configure network resources for the service request.

8. The apparatus according to any of the claims 1 to 7, wherein the apparatus is a part of a trusted site with level of security fulfilling a security requirement.

9. The apparatus according to any of the claims 1 to 8 comprising: a set of protocol configurators, a protocol manager and a shared data layer.

10. The apparatus according to claim 9, wherein the protocol configurators comprising: means for configuring resources for certain protocol, wherein the protocol configurator is aware of features the protocol supports.

11. The apparatus according to claim 9 or 10, wherein the protocol manager comprising: means for keeping consistency of the functionality, wherein the protocol manager is aware of protocol sets the different network components are allowed to configure and where the shared data layer is used to store the data.

12. The apparatus according to claim 9, 10 or 11, wherein the shared data layer comprising: means for storing data and share the data over multiple data servers.

13. An apparatus comprising at least one processor and at least one memory, said at least one memory stored with computer program code thereon, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: receiving by the apparatus a service request from a user equipment; examining whether to forward at least a part of the service request to another entity in a network; determining by the apparatus available resources for processing the at least a part of the service request in the network, when the examining indicates the apparatus to forward at least a part of the service request to another entity in the network; selecting among the available resources another entity for configuring the requested service for the user equipment; and communicating with the selected entity to update context of the user equipment.

14. A method comprising: receiving by a control-plane network entity a service request from a user equipment; examining whether to forward at least a part of the service request to another entity in a network; determining by the control-plane network entity available resources for processing the at least a part of the service request in the network, when the examining indicates the apparatus to forward at least a part of the service request to another entity in the network; selecting among the available resources another entity for configuring the requested service for the user equipment; and communicating with the selected entity to update context of the user equipment.

15. The method according to claim 14 comprising: delivering a security key via an operation, administration, and management function to one or more c-plane entities.

16. The method according to claim 14 comprising: obtaining a security key by performing a registration procedure with a server hosting a shared data layer; and using the security key to access the shared data layer.

17. The method according to claim 16 comprising: obtaining a user equipment key; and performing radio resource control messaging for the user equipment by using the security key and the user equipment key.

18. The method according to any of the claims 14 to 17 comprising: sharing rights for context of the user equipment to the one or more c-plane entities.

19. The method according to any of the claims 14 to 18, wherein said examining comprises at least one of the following: examining whether the apparatus has enough processing capability to handle the request, examining how much latency would result if the request were handled by the apparatus.

20. The method according to any of the claims 14 to 19 comprising: using information of network features and remaining resources to determine whether the control-plane network entity can configure network resources for the service request.

21. The method according to any of the claims 14 to 20, wherein the control-plane network entity is a part of a trusted site with level of security fulfilling a security requirement.

22. The method according to any of the claims 14 to 21, wherein the control-plane network entity comprises a set of protocol configurators, a protocol manager and a shared data layer.

23. The method according to claim 22, wherein the protocol configurators configure resources for certain protocol, wherein said protocol configurator is aware of features the protocol supports.

24. The method according to claim 22 or 23, wherein the protocol manager keeps consistency of the functionality, wherein the protocol manager is aware of protocol sets the different network components are allowed to configure and where the shared data layer is used to store the data.

25. The method according to claim 22, 23 or 24, wherein the shared data layer stores data and shares the data over multiple data servers.