Improvements in and relating to a telecommunication network

Abstract

A network comprising an Open Ran radio unit (O-RU) node, preferably to report update of parameters 104 for an action and a system in O-RAN, configuring O-RU node by means of a near real-time RAN Intel

Description

The present invention relates to an improved service model for use in a telecommunication network. It finds particular, but not exclusive, utility in a Sixth Generation (6G) Open Radio Access Network (O-RAN) network, but other systems can benefit from an embodiment of the invention. Open and disaggregated network structure has become a main feature and technology trend within a 6G network. In particular, the concept of open radio access network (Open RAN) enables a more open and disaggregated radio access network architecture to improve network flexibility, and avoid vendor lock-in. In order to encourage the development of a nonfragmented Open RAN system, the O-RAN alliance organisation has developed an O-RAN architecture, that enables the building of the virtualised RAN on open hardware and cloud platform, with embedded Artificial Intelligence (Al) powered radio control. In particular, xApps / rApps can be developed to configure E2 nodes (including Central Unit (CU) and Distributed Unit (DU)) using Al, through interfaces such as 01 and A1. A high level architecture used in O-RAN is shown in Figure 1, which shows an open radio access network (O-RAN) including radio units (RU), digital units (DU), control units (CU) -control plane (CP), and user planes (UP) as O (O-RAN) -RU, O-DU, O-CU-CP, O-CU-UP. RAN Intelligent Controller (RIC) is a software-defined component of the Open Radio Access Network (Open RAN) architecture that's responsible for controlling and optimizing RAN functions. RIC is a logical node that can collect information on cell sites transmitted and received by a User Equipment (UE), O-eNB, O-DU, O-CU-CP, or O-CU-UP. The RIC can be implemented in the form of a server concentrated in one physical place or it can be implemented as a logical function within the Base Station (gNB). In the following, the nodes that are connected to RIC through the E2 interface, are referred to as E2 nodes. It is understood that embodiments of the invention may generally be applied to E2 nodes, regardless of what the E2 nodes are. Here, E2 nodes may be understood as objects constituting a RAN that can operate according to the O-RAN standard, and may be referred to as an E2 node. An E2 node may also refer to an O-eNB. xApps can be developed in the Near-RT RIC and provide control to the RAN functions in the E2 nodes. Such examples can be found in B. Zahnstecher et al., "Energy Efficiency," 2022 IEEE Future Networks World Forum (FNWF), Montreal, QC, Canada, 2022, pp. 1-133, doi: 10.1109 / FNWF55208.2022.00137. rApps can developed in Non-RT RIC as a platform application that provides analytics related function and RAN governing policy function. Currently, the configuration of O-RU is performed through the O1 interface, however, there is no direct interface between xApps / rApps and O-RU, so that O-RU can be intelligently configured effectively. A 6G network is expected to be capable of configuring O-RU parameters automatically. Embodiments of the invention provide a new RU service model that will enable the intelligent configuration of O-RU via xApps and rApps in near-RT RIC and non-RT RIC. In particular, embodiments of the invention provide apparatus, methods, functions and interfaces based on an O-RAN architecture, to enable intelligent control of O-RU in O-RAN. It is an aim of an embodiment of the present invention to address issues in the prior art, whether mentioned herein or not. According to the present invention there is provided an apparatus and method as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the description which follows. According to a first aspect of the present invention, there is provided a method of operating a telecommunication network, the network comprising at least one Radio Unit, O-RU, node and at least one intelligent system in an Open-Radio Access Network, O-RAN, architecture, comprising the step of configuring the at least one RU node by means of at least one of a near-real-time RAN Intelligent Controller, RIC, and a non-real-time RIC. In an embodiment, an xApp is provided in the near-real-time RIC or an rApp is provided in the non-real-time RIC. In an embodiment, an Artificial Intelligence / Machine Learning, AI / ML, model is deployed as or within an xApp instance In an embodiment, the AI / ML model is arranged to be updated via an xApp software update. In an embodiment, an AI / ML model is decoupled from an xApp and is arranged to be enabled or updated via an xApp file configuration. In an embodiment, an O-RAN Network Function, NF, is arranged to be managed via an O1 interface and an authorised service orchestration and management, SMO, framework and, additionally, a further interface is provided whereby the O-RU functionality may be controlled directly from near-real-time RIC. In an embodiment, a control model is provided which allows the configuration of the O-RU according to actions from the xApp or rApp. In an embodiment, an interface is provided between the O-RU and one or more of the near-real-time RIC and the non-real-time RIC, wherein the interface comprises at least one of: a list of IDs of certain O-RU components to be configured; and certain parameters of the O-RU to be configured. In an embodiment, the certain parameters comprise one or more of antenna tilt and ADC quantisation level. In an embodiment, the interface is arranged to acknowledge completion of actions from the O-RU to the near-real-time RIC or the non-real-time RIC. In an embodiment, the O-RU is arranged to report update of parameters after an action is taken. According to a second aspect of the present invention, there is provided as apparatus arranged to perform the method of the first aspect. Although a few preferred embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims. For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example only, to the accompanying diagrammatic drawings in which: Figure 1 shows an O-RAN high level architecture known in the prior art; Figure 2 shows interfaces to enable near-RT RIC control of O-RU according to an embodiment of the invention; Figure 3 shows interfaces to enable Non-RT RIC control of O-RU according to an embodiment of the invention; Figure 4 shows interfaces to enable both Non-RT RIC and near-RT RIC control of O-RU according to an embodiment of the invention; Figure 5 shows O-RU xApp - high level architecture according to an embodiment of the invention; Figure 6a shows a prior art configuration; Figure 6b shows a means of enabling direct configuration of O-RU by near-RT RIC according to an embodiment of the invention; Figure 7a shows a prior art configuration; Figure 7b shows a means of enabling direct configuration of O-RU by non-RT RIC according to an embodiment of the invention; Figure 8a shows a representation of O-RU control CONTROL service style - direct control mode RIC according to an embodiment of the invention; Figure 8b shows a representation of O-RU control CONTROL service style - Hierarchy mode according to an embodiment of the invention; Figure 9 shows xApps and RU functions according to an embodiment of the invention; Figure 10 shows an example of PA requirements for O-RU interfaces to collect data, monitor PA performance and allow real time control and configuration according to an embodiment of the invention; Figure 11 shows an example of Precoding parameters using an interface for O-RU according to an embodiment of the invention; Figure 12 shows a procedure example to configure PA(s) of O-RU using an interface according to an embodiment of the invention; and Figure 13 shows a procedure example to configure Precoder(s) of O-RU using an interface according to an embodiment of the invention. Embodiments of the invention relate to an apparatus and method to enable the controlling of O-RU by an RIC in a radio access network. In particular, it provides at least one new interface and at least one new Information Element (IE) for intelligent control and configuration of O-RU, in accordance with an open radio access network (O-RAN) standard of a wireless communication system. Further, embodiments provide an apparatus and method for transmitting a list of IDs of the RUs that are to be configured. Embodiments further provide a list of lEs, apparatus and method for configuring an O-RU node by the RIC according to the aforementioned O-RU ID list, so that the particular O-RU will work according to the control of the RIC. Figures 2-4 show certain examples of new interfaces (labelled as such) in the context of an O-RAN architecture. The known interfaces from the prior art are labelled with their usual names. Note that in Figures 3 and 4 the new interfaces are different from the prior art O1 interface shown, because O1 is the management interface while the new interface contains RU Control configurations. Also note the new interfaces between non- and near-RT RIC to O-RU may need exposure of parameters / data from internal functional blocks in non- and near-RT RIC, such as any AI / ML functions. In the following, the new parameters, interfaces, and procedures are described for each method, respectively. Embodiments of the invention provide at least one of the following features: 1. New enabler within non-RT RIC and near-RT RIC for O-RU configuration and control. This includes one or multiple new rApps / xApps, namely the O-RU control xApps, at non-RT RIC or near-RT RIC 2. New RU Service Model CONTROL service style, between non-RT RIC / near-RT RIC and the RU control function at the O-RU, where the new control model allows the configuration of RU according to the actions from the xApps in near-RT RIC, or rApps from non-RT RIC specified in point 1 above. 3. New interfaces between non-RT RIC / near-RT RIC and the O-RU, where the interfaces are: 1) a list of the IDs of the RU components to be configured; 2) parameters of the RUs to be configured, e.g., antenna tilt, ADC quantisation level, etc. 4. Acknowledge of completion of actions from O-RU to non-RT RIC or near-RT RIC (e.g., Ack or NAck of actions) through the newly defined interfaces. 5. O-RU reporting of parameters update after action. 6. A procedure related to enabling the control of O-RU with the new interfaces and lEs above. Figure 5 shows a high level architecture of an embodiment of the present invention. As illustrated in Figure 5, the non-RT RIC (101) in service orchestration and management (SMO) framework enables non-real-time control and optimization of RAN elements and resources and policy-based guidance to the applications / features in Near-RT RIC (102) through an A1 interface. In one embodiment of the invention, one or multiple xApps are added, i.e., the O-RU control xApps (103) in Near-RT RIC. The xApp makes a decision on, e.g., quantisation levels of the ADCs, the antenna tilt, etc., according to the Key Performance Indicators (KPIs) of the network and / or policies from the SMO. The decision made by 103 may lead to update of the list of RUs to be configured. These parameters (104) shall be passed from near-RT RIC to O-RU, and O-RU shall be configured accordingly and dynamically. The O-RU shall send their status monitoring (104) (e.g., current quantisation level, ADC characteristics, antenna tilt etc) to near-RT RIC, for 103 to update its decisions accordingly. From an architecture point of view, with the new interface, the new interface enables the configuration of O-RU directly by near-RT RIC, rather than by using open fronthaul from E2 nodes. An illustration of such a concept is shown in Figure 6b, which is contrasted with Figure 6a, which shows the prior situation. In another embodiment of the invention, with the new interface, the new interface enables the configuration of O-RU directly by non-RT RIC, rather than via the 01 interfaces. An illustration of such a concept is given in Figure 7b, which is contrasted with Figure 7a, which shows the prior situation. O-RAN Near-RT RIC can control O-RU nodes through RU Application Protocol message, RUAP RIC Control Request Message. The associated message flows and Message Information Elements (IE) are shown in Figures 8a (showing direct control mode) and 8b (showing hierarchy mode). Figure 9 shows the interactions between xApps and RU functions. In one example, the xApp may configure the parameters of Analog to Digital Controllers (ADCs), and the RU function may be an ADC. In another example, the xApp may control the non-linearity of a power amplifier (PA), and the RU function may be a PA. Table 1 below shows a header format used in an embodiment. This Control header format is part of the RIC CONTROL message sent by the Near-RT RIC to an O-RU and is required for RIC Control Procedure. Table 1: Control header format is part of the RIC CONTROL message lE / Group Name Presence Range IE type and reference Semantics description CHOICE Control Header Format >E2SM-CCC Control Header Format xx M Table 1 below shows a Control Header format. Table 1: Control Header format lE / Group Name Presenc e Range IE type and reference Semantics description RIC Style Type M x.x.x Table below shows a Control message format. This information element is part of the RIC CONTROL message sent by the Near-RT RIC to an E2 Node, in this case, E2SM-CCC Control Message Format xx, it sent to O-RU and is required for RIC Control Procedure. Table 3: E2SM-CCC Control Message Format xx lE / Group Name Presence Range IE type and reference Semantics description CHOICE Control Message Format >E2SM-CCC Control M Message Format 1 >E2SM-CCC Control Message Format 2 M >E2SM-CCC Control Message Format xx M Table 2 below shows E2SM-CCC Control Message Format xx showing the O-RU configuration information. It could have previous O-RU configuration information and new O-RU 5 configuration information. Information is in an OCTET string container, and can be further defined later in the standard, as needed. Table 2: E2SM-CCC Control Message Format xx lE / Group Name Presence Range IE type and reference Semantics description List of Configuration Structures 1..<maxnoofC onfigurations> Indicates the configuration structures that are controlled within the message. >RU Configuration Structure Name M Indicates the RAN Configuration Structure name. >Old Values of Attributes 0 OCTET STRING Provides the old attribute values for the respective O-RU Configuration Structure. >New Values of Attributes 0 OCTET STRING Provides the new attribute values for the respective O-RU Configuration Structure 10 The following relates to an example use case for O-RU configuration via xApps / rApps. Prior art O-RAN architecture supports the configuration of O-RU through the 01 interface. In the next generation network, there are a few use cases that will need O-RU configuration via xApps and rApps. For example, Al can be used to enhance Power Amplifier (PA) non-linearity, 15 optimise ADC quantisation bits, and optimise antenna tile and beam etc. 1. The PA non-linearity use case: The PA Non-Linearity Use Case focuses on addressing the significant energy consumption of base stations in mobile telecommunications, where 60-80% of the energy footprint is attributed to base stations and 60-80% of that is due to Linear Power Amplifiers (LPAs) being constantly active and transmitting at much higher power levels than User Equipment (UEs) with relatively low efficiency. Recently, various algorithms have been introduced to enhance LPA efficiency. Al techniques can predict and compensate for the non-linear behaviour of LPAs, allowing for more efficient power usage and reduced energy consumption. For instance, in Ma, Rui, et al. "A New Frontier for Power Amplifier enabled by Machine Learning." MICROWAVE JOURNAL 64.4 (2021): 22-32, the authors demonstrate how compact data-driven Al techniques can unlock the full potential of high-performance power amplifiers for flexible and wideband wireless applications. In J. Lu et al., "Machine Learning based Adaptive Predistorter for High Power Amplifier Linearization," 2019 IEEE Cognitive Communications for Aerospace Applications Workshop (CCAAW), Cleveland, OH, USA, 2019, pp. 1-6, doi: 10.1109 / CCAAW.2019.8904896, modern machine learning (ML) methods are proposed for predicting the dynamic non-linear behaviour of wideband RF power amplifiers (PAs). In Towards 6G Al: Al-based Non-linearity Compensator, https: / / research.samsung.com / blog / Towards-6G-AI-AI-based-Non-linearity-Compensator, a technology that expands uplink communication coverage by allowing a UE to boost transmit power for a given PA is introduced, where increased non-linearity induced by the PA due to power-boosting is compensated at the base station receiver employing AL As a result of the above examples, a new interface between the O-RU and the Near-RT RIC is desirable not only for data collection and O-RU components monitoring but also for the control and improvement of individual components, such as PA efficiency. Additionally, such a new interface enables future disaggregation of O-RU components and offloads some signal processing tasks to xApps, reducing O-RU processing requirements in a near real-time manner. According to the latest O-RAN alliance specifications, O-RAN-WG7.OMAC.HRD.0-R003-v02.00 “O-RAN Working Group 7 Whitebox Hardware Hardware Reference Design Specification for Outdoor Macrocell with Split Architecture Option 7.2”, Power Amplifier Interface specifications are limited to those shown on Table 5, below, and can be provided through the 01 and / or the open fronthaul for the Non-RT RIC and O-DU, respectively. However, there is no direct interface to the Near-RT RIC, which is crucial for real-time processing flexibility in O-RAN. Furthermore, O-RAN specifications do not detail how mMIMO PAs configuration can be automated to optimize which PA will be enabled and disabled for power-efficient RF chain transmission. Embodiments of the invention provide that the new interface supports the PA Bias conditions (e.g., Drain bias current, High-voltage supply line, and on-chip temperature) as shown in Table 6 and Figure 10, enabling O-RU data collection, monitoring, real-time enable / suspend, control, override messages (e.g., O-DU messages), and execution of xApp commands for O-RU PA components directly to and from the Near-RT RIC. Table 5: Power Amplifier Interface Specifications Item Name Description RF Enable The enable input should be compatible with 1.8V logic and tolerate 3.3V as required. A logic high enables the PA. A logic low disables the device and places it in a minimum dissipation mode. RF Output RF outputs support 50-ohm single ended to properly interface to a directional coupler, isolator, switch, or antenna. RF Input RF inputs should support 50-ohm, single ended match to the transceiver output or preamp. The new interface set out in an embodiment of this invention can be used to configure various parameters to optimize PA performance and energy efficiency. Some examples of these parameters include: • Bias conditions: The interface can control and configure bias conditions for the PA, such as drain bias current, high-voltage supply line, and on-chip temperature, allowing for optimal operation and energy efficiency, L. Riordan “Discrete and Integrated Control of Power Amplifiers in Base-Station Applications” https: / / www.analog.com / en / analog-dialogue / articles / power-amplifier-control-in-base-stations.html. • Operating mode: The interface can enable or disable different operating modes of the PA, such as linear mode for better signal quality or non-linear mode for higher power efficiency, depending on the requirements of the specific communication scenario. • Input and output power levels: The interface can be used to dynamically adjust the input and output power levels of the PA based on real-time network conditions, traffic load, and user equipment requirements. • Gain control: The interface can control the gain settings of the PA, enabling precise 5 control of the output power and linearity, as well as reducing power consumption when the required output power is lower. • Load impedance tuning: The interface can be used to control and configure the load impedance of the PA to match the antenna impedance for optimal power transfer and reduced energy loss. 10 • Temperature compensation: The interface can be used to monitor the PA's temperature and adjust the operating parameters accordingly to maintain optimal performance and prevent thermal degradation. • Pre-distortion settings: The interface can control and configure the PA's pre-distortion settings to compensate for non-linearities in the PA's response, improving signal 15 quality and reducing distortion. Table 6: Examples for possible monitorable and configurable parameters via the new interface for PA non-linearity Parameter !!■ Parameter Parameter Value Type Semantics Description pi Bias conditions Numeric (Volts, Amps) Control and configure bias conditions for the PA, such as drain bias current, high-voltage supply line, and on-chip temperature. P2 Operating mode Linear, Non linear Enable or disable different operating modes of the PA, such as linear mode for better signal quality or non-linear mode for higher power efficiency. P3 Input and output power levels Numeric (dBm) Dynamically adjust the input and output power levels of the PA based on real-time network conditions, traffic load, and user equipment requirements. P4 Gain control Numeric (dB) Control the gain settings of the PA, enabling precise control of the output power and linearity, as well as reducing power consumption. P5 Load impedance tuning Numeric (Ohms) Control and configure the load impedance of the PA to match the antenna impedance for optimal power transfer and reduced energy loss. P6 Temperature compensation Numeric (°C) Monitor the PA's temperature and adjust the operating parameters accordingly to maintain optimal performance and prevent thermal degradation. P7 P re-distortion settings Numeric, Enable / Disable Control and configure the PA's predistortion settings to compensate for nonlinearities in the PA's response, improving signal quality and reducing distortion. 2. ADC Quantization Bits Optimization: The ADC quantization bits optimization use case focuses on improving the efficiency and performance of the ADC in a radio access network by intelligently adapting the number of quantization bits, as well as other ADC settings, in response to the specific network conditions and requirements see e.g. A. Kaushik, C. Tsinos, E. Vlachos and J. Thompson, "Energy Efficient ADC Bit Allocation and Hybrid Combining for Millimeter Wave MIMO Systems," 2019 IEEE Global Communications Conference (GLOBECOM), Waikoloa, HI, USA, 2019, pp. 1-6, doi: 10.1109 / GLOBECOM38437.2019.9014072. ADCs are responsible for converting analog signals from the radio frequency (RF) domain into digital signals that can be processed by digital signal processors (DSPs). The quantization process involves discretizing the continuous analog signal into a finite number of levels, which are represented by a specific number of bits. The number of quantization bits determines the resolution and accuracy of the digitized signal and directly impacts the signal quality and the overall system performance. The ADC quantization optimization may be performed for one or more of the following scenarios / settings: 1. Dynamic Adjustment of Quantization Bits: In this use case, the RIC employs Al-driven algorithms to dynamically adjust the number of quantization bits used by the ADC based on the network conditions and requirements. For example, when the network is experiencing high traffic or when high signal fidelity is necessary, the RIC might increase the number of quantization bits to ensure better signal quality. On the other hand, during periods of low traffic or when signal quality requirements are less stringent, the RIC could reduce the number of quantization bits to save power and reduce overall system complexity. 2. Sampling Rate Optimization: Along with the number of quantization bits, the sampling rate of the ADC is another crucial factor affecting the signal quality and system performance. The RIC can adapt the ADC sampling rate based on the bandwidth requirements of the network, optimizing the trade-off between signal quality and energy consumption. For instance, during periods of low traffic, a lower sampling rate can be used to save energy without significantly impacting the signal quality. 3. Dynamic Range Adaptation: The dynamic range of the ADC is the range of input signal amplitudes it can accurately convert. In this use case, the RIC can optimize the dynamic range of the ADC based on the signal conditions and network requirements. For example, in situations with high interference or noise, the RIC might increase the dynamic range to ensure that the useful signal components are accurately captured and converted. 4. Noise Reduction and Filtering: The RIC can apply noise reduction and filtering techniques to improve the signal quality and reduce the impact of noise and interference on the digitized signal. This may involve adjusting the ADC's internal filtering settings or applying external digital signal processing techniques to the converted signal. Overall, embodiments of the invention provide a new interface where xApps and rApps may modify the ADC configuration parameters which include: • Quantization Bits: The RIC can remotely adjust the number of quantization bits used by the ADC. By increasing or decreasing the number of bits, the RIC can balance the trade-off between signal quality, resolution, and system complexity. • Sampling Rate: The RIC can control the sampling rate of the ADC, which determines the rate at which the continuous analog signal is sampled and converted into discrete digital values. Optimizing the sampling rate based on bandwidth requirements and network conditions can enhance the efficiency of the conversion process. • Dynamic Range: The RIC can configure the dynamic range of the ADC, which is the range of input signal amplitudes the ADC can accurately convert. By optimizing the dynamic range, the RIC can ensure that the useful signal components are captured and converted effectively, even in challenging signal conditions. • Input Voltage Range: The RIC can set the input voltage range for the ADC, which affects the ADC's sensitivity and noise performance. By adjusting the input voltage range, the RIC can optimize the ADC's performance for the specific network conditions and signal characteristics. • Filtering Settings: The RIC can configure the ADC's internal filtering settings or apply external digital signal processing techniques to the converted signal. This can help reduce noise and improve signal quality in the digital domain. • Operating Modes: The RIC can control the operating modes of the ADC, such as 5 power-saving or high-performance modes, to balance power consumption and performance based on network requirements. • Performance Monitoring and Feedback: The RIC can set parameters related to the collection and reporting of ADC performance metrics. This can include specifying the metrics to be monitored (e.g., signal-to-noise ratio, error rates, power consumption), 10 the reporting intervals, and any thresholds or triggers for adaptive control. Table 7 below gives a summary of the possible configurations via the new interface for ADC. Table 7: Proposed DAC / ADC Interface Specifications for O-RU Parameter ID Parameter Parameter Value Type Semantics Description P1 Quantization Bits Numeric (bits) Remotely adjust the number of quantization bits used by the ADC to balance the trade-off between signal quality, resolution, and system complexity. P2 Sampling Rate Numeric (Samples / second) Control the sampling rate of the ADC, optimizing the rate based on bandwidth requirements and network conditions. P3 Dynamic Range Numeric (dB) Configure the dynamic range of the ADC, ensuring the useful signal components are captured and converted effectively. P4 Input Voltage Range Numeric (Volts) Set the input voltage range for the ADC, affecting the ADC's sensitivity and noise performance. P5 Filtering Settings Enable / Disable, Numeric Configure the ADC's internal filtering settings or apply external digital signal processing techniques to the converted signal. P6 Operating Modes Power-saving, High-performance Control the operating modes of the ADC to balance power consumption and performance based on network requirements. P1 Quantization Bits Numeric (bits) Remotely adjust the number of quantization bits used by the ADC to balance the trade-off between signal quality, resolution, and system complexity. 3. Antenna Tile and Beam Optimization: The Antenna Tilt and Beam Optimization use case focuses on improving the performance and efficiency of radio access networks, particularly in massive MIMO (systems, by intelligently managing and optimizing antenna settings such as tilt angles, beamforming weights, and beam steering directions. The main goal is to enhance network capacity, coverage, and overall performance while minimizing interference and power consumption. In the following an expanded view of the Antenna Tilt and Beam Optimization use case is provided: 1. Adaptive Antenna Tilt Adjustment: The RIC employs Al-driven algorithms to dynamically adjust the antenna tilt angles based on real-time network conditions, user distribution, and performance requirements. By optimizing the antenna tilt, the RIC can focus the antenna's radiation pattern towards areas with higher user density or areas that require improved coverage, maximizing the network's efficiency and minimizing interference with other cells. 2. Intelligent Beamforming: Beamforming is a technique used in massive MIMO systems to transmit and receive signals in specific directions, enhancing the signal strength at the receiver and improving overall network capacity. The RIC can adaptively adjust the beamforming weights for each antenna element based on the user's locations and the network conditions, ensuring that the desired signal is transmitted or received in the most efficient manner possible. In mmWave transmission, beamforming is particularly advantageous for improving signal-to-noise ratios (SNR) and reducing interference between User Equipment (UE) signals in high-density environments e.g. see Mohsin, Mustafa, Jordi Mongay Batalla, Evangelos Pallis, George Mastorakis, Evangelos K. Markakis, and Constandinos X. Mavromoustakis. 2021. "On Analyzing Beamforming Implementation in O-RAN 5G" Electronics 10, no. 17: 2162. https: / / doi.org / 10.3390 / electronics10172162. The O-RU mMIMO architecture features a beamformer block and supports precoding in the O-RU (Category B). However, the open front-haul interface used for beam configuration struggles to meet ultra-low latency requirements. Beam Mobility Management (BMM) is an O-RAN use case that employs the Grid of Beams (GoB) beamforming method, with various xApps proposed to minimize beam failure and maximize SNR e.g. M. Hoffmann, “Beamforming and Open RAN”, https: / / rimedolabs.com / blog / beamforming-and-open-ran / . The E2 interface can present a time bottleneck for transmitting necessary data from the O-RU and configuration messages from xApps. Consequently, a new interface between the O-RU and Near-RT RIC is needed to reduce latency for both data collection and control signals. For example, some Downlink (DL) precoding parameters sent by O-RAN using the open Front-Haul (FH) interface between the O-DU and O-RU are listed in Table 8 e.g. O-RAN.WG4.CUS.0-v10.00 “O-RAN Working Group 4 (Open Fronthaul Interfaces WG) Control, Userand Synchronization Plane Specification”. 3. Dynamic Beam Steering: Beam steering involves directing the antenna's main radiation lobe towards the desired user or group of users to improve signal quality, minimize interference, and increase network capacity. The RIC can dynamically steer the antenna beams based on user distribution, mobility patterns, and network conditions, ensuring that the network can adapt to changing user requirements and maintain optimal performance. 4. Interference Management: By intelligently adjusting the antenna tilt, beamforming weights, and beam steering directions, the RIC can minimize interference between neighboring cells and reduce the impact of external sources of interference. This can lead to improved signal quality, reduced call drops, and better overall network performance. 5. Energy Efficiency: Antenna Tilt and Beam Optimization can also contribute to energy efficiency in radio access networks. By focusing the transmitted energy in the desired directions and avoiding wasteful energy dispersion, the network can achieve its performance objectives with lower power consumption. This can be particularly beneficial in dense urban environments or during periods of low network traffic. 6. Performance Monitoring and Feedback: The RIC continuously monitors key performance metrics, such as signal-to-interference-plus-noise ratio (SINR), cell load, and user satisfaction, and uses this information to adapt the antenna settings in realtime. This allows the RIC to maintain optimal network performance and respond to changing conditions quickly and effectively. Table 8: O-RU DL Precoding configuration parameters example. Parameter Name Description codebookindex precoder codebook used for transmission LayerlD Layer ID for DL transmission crsReMask CRS resource element mask txScheme transmission scheme beamldAPI beam id to be used for antenna port 1 beamldAP2 beam id to be used for antenna port 2 In summary, the Antenna Tilt and Beam Optimization use case focuses on intelligently managing and optimizing antenna settings in a RAN to enhance network capacity, coverage, and overall performance while minimizing interference and power consumption. The interface enables the RIC to configure and control various parameters to improve network performance, including but not limited to: • Antenna Tilt Angle: The RIC can remotely adjust the electrical and / or mechanical tilt angles of antenna elements to optimize coverage and minimize interference. Both downtilt and uptilt angles can be modified based on network conditions and user distribution. • Beamforming Weights: The RIC can control complex weights applied to each antenna element in the array, forming the desired radiation pattern. Optimizing these weights helps maximize signal strength at the receiver, enhance network capacity, and reduce interference. • Beam Steering Direction: The RIC can configure the main radiation lobe's direction to improve signal quality, minimize interference, and increase network capacity. This may involve specifying azimuth and elevation angles or providing desired spatial coordinates for the main lobe. • Transmit Power: The RIC can control the transmit power of individual antenna elements or the overall array, adjusting power levels based on network conditions, user requirements, and energy-saving objectives. • Antenna Polarization: The RIC can configure antenna element polarization (e.g., vertical, horizontal, or circular) to enhance signal quality and mitigate multipath fading. • Antenna Array Geometry: In some instances, the RIC may adjust the physical layout or arrangement of antenna elements within the array to optimize the radiation pattern and maximize network performance. • VM Resolution: The RIC can control the number of bits resolution for vector modulators (VM) to manage phase. • DVGA Resolution: The RIC can control digital variable gain amplifiers (DVGAs) to manage amplitude. • Beamformer On-Chip LDO: The RIC can configure the voltage regulator that generates voltage supply for the serial port interface circuitry, reducing the number of supply domains required and enabling fast startup and control during normal operation. 5 • RF Power Overload Circuit: The RIC can manage a receive channel overload detection circuit to prevent potential device damage due to blocker instances. The new interface supports the AI / ML flow works and can provide a new service for beamforming monitoring and controlling, including, for example, the ones are listed in Table 9 10 along with Figure 11. Table 9: DL Antenna Tilt and Beam (include the precoder in the O-RU) Optimization monitoring and configuration parameters example Parameter Parameter Parameter Value Semantics Description P1 Antenna Tilt Angle -20 to 10 degrees Remotely adjust the electrical and / or mechanical tilt angles of antenna elements to optimize coverage and minimize interference. P2 Beamforming Weights Complex numbers Control complex weights applied to each antenna element in the array, forming the desired radiation pattern. P3 Beam Steering Direction Azimuth, Elevation angles or spatial coordinates Configure the main radiation lobe's direction to improve signal quality, minimize interference, and increase network capacity. P4 Transmit Power Numeric (dBm) Control the transmit power of individual antenna elements or the overall array, adjusting power levels based on network conditions. P5 Antenna Polarization Vertical, Horizontal, Circular Configure antenna element polarization to enhance signal quality and mitigate multipath fading. P6 Antenna Array Geometry Layout or arrangement Adjust the physical layout or arrangement of antenna elements within the array to optimize the radiation pattern and maximize network performance. P7 VM Resolution Numeric (bits) Control the number of bits resolution for vector modulators (VM) to manage phase. P8 DVGA Resolution Numeric (bits) Control digital variable gain amplifiers (DVGAs) to manage amplitude. P9 Beamformer On- Chip LDO Numeric (Volts) Configure the voltage regulator that generates voltage supply for the serial port interface circuitry. P10 RF Power Overload Circuit Enable / Disable Manage a receive channel overload detection circuit to prevent potential device damage due to blocker instances. 4. PA Activation and Deactivation: The PA Activation and Deactivation use case focuses on intelligently managing the activation and deactivation of power amplifiers in a radio access network, specifically in massive MIMO (Multiple-Input, Multiple-Output) systems. This use case aims to optimize the RF chain transmission's power efficiency while maintaining network performance, which is particularly important in energy-saving scenarios. In massive MIMO systems, numerous power amplifiers are utilized to drive the antenna elements. By selectively activating or deactivating specific PAs, the network can reduce energy consumption without compromising the required level of network performance. The following lists certain possible optimization scenarios that involve PA activation / deactivation: 1. Dynamic PA Activation and Deactivation: The RIC employs Al-driven algorithms to dynamically activate or deactivate PAs based on real-time network conditions, traffic load, and specific performance requirements. For example, during periods of low network traffic, some PAs can be deactivated to save energy while still maintaining the required level of network performance. Conversely, when network traffic is high, the RIC may activate more PAs to handle the increased demand and ensure reliable communication. 2. Energy-Efficient PA Selection: The RIC can adaptively select which PAs to activate or deactivate, considering factors such as energy efficiency, PA performance, and network conditions. This adaptive selection may involve analyzing the individual PA energy consumption, output power, and efficiency, enabling the RIC to choose the most energy-efficient PAs for activation. 3. PA Load Balancing: To ensure optimal performance and prevent excessive wear on specific PAs, the RIC can balance the workload across the available PAs. Load balancing strategies can involve periodically alternating the active PAs or assigning PAs to different antenna elements or sectors based on their energy efficiency and performance characteristics. 4. Proactive Maintenance and Monitoring: The RIC continuously monitors the performance metrics of the PAs, such as temperature, output power, and efficiency, and uses this information to inform its activation and deactivation decisions. By analyzing the performance data, the RIC can identify potential issues or inefficiencies and take appropriate corrective actions, such as adjusting the PA settings or scheduling maintenance. 5. Integration with Energy-Saving Scenarios: PA Activation and Deactivation plays a crucial role in energy-saving scenarios, such as sleep mode or low-power mode. In these scenarios, the RIC can deactivate a significant portion of the PAs, reducing the overall energy consumption of the network. Furthermore, the RIC can intelligently reactivate PAs when network traffic increases or when specific performance requirements demand it. Based on the aforementioned scenarios, the set of parameters that can be configured through the new interface are: • PA Activation Status: The RIC can remotely activate or deactivate individual PAs or groups of PAs based on real-time network conditions, traffic load, and specific performance requirements. • PA Output Power: The RIC can control the output power of each PA, adjusting the power levels to balance network performance, coverage, and energy efficiency. • PA Operating Modes: The RIC can configure different operating modes for the PAs, such as power-saving or high-performance modes, to balance power consumption and performance based on network requirements. • PA Bias Settings: The RIC can adjust the bias settings of the PAs, which can have a significant impact on their efficiency, linearity, and power consumption. By optimizing the bias settings, the RIC can improve the overall energy efficiency of the radio access network. • Load Balancing: The RIC can control the allocation of RF transmission tasks among the available PAs, ensuring an even distribution of workload and preventing excessive wear on specific PAs. 5 Table 10 summarize the examples of parameters that can be configured through the new interface. Table 10: Examples for possible configurations via the new interface for Antenna PA Activation and Deactivation. Parameter |||||||||||| Parameter Parameter Value Semantics Description P1 Antenna Tilt Angle -20 to 10 degrees Remotely adjust the electrical and / or mechanical tilt angles of antenna elements to optimize coverage and minimize interference. P2 Beamforming Weights Complex numbers Control complex weights applied to each antenna element in the array, forming the desired radiation pattern. P3 Beam Steering Direction Azimuth, Elevation angles or spatial coordinates Configure the main radiation lobe's direction to improve signal quality, minimize interference, and increase network capacity. P4 Transmit Power Numeric (dBm) Control the transmit power of individual antenna elements or the overall array, adjusting power levels based on network conditions. P5 Antenna Polarization Vertical, Horizontal, Circular Configure antenna element polarization to enhance signal quality and mitigate multipath fading. Figure 12 shows an example procedure of PA configuration use case, it shows that the new interface allows inter loop between the Near RT-RIC and the O-RU to directly interact between 15 each other. Further, Figure 13 shows a second example procedure of an O-RU Precoder configuration use case. At least some of the example embodiments described herein may be constructed, partially or wholly, using dedicated special-purpose hardware. Terms such as ‘component’, ‘module’ or ‘unit’ used herein may include, but are not limited to, a hardware device, such as circuitry in the form of discrete or integrated components, a Field Programmable Gate Array (FPGA) or Application Specific Integrated Circuit (ASIC), which performs certain tasks or provides the associated functionality. In some embodiments, the described elements may be configured to reside on a tangible, persistent, addressable storage medium and may be configured to execute on one or more processors. These functional elements may in some embodiments include, by way of example, components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. Although the example embodiments have been described with reference to the components, modules and units discussed herein, such functional elements may be combined into fewer elements or separated into additional elements. Various combinations of optional features have been described herein, and it will be appreciated that described features may be combined in any suitable combination. In particular, the features of any one example embodiment may be combined with features of any other embodiment, as appropriate, except where such combinations are mutually exclusive. Throughout this specification, the term “comprising” or “comprises” means including the component(s) specified but not to the exclusion of the presence of others. Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, 5 or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A method of operating a telecommunication network, the network comprising at least one Radio Unit, O-RU, node and at least one intelligent system in an Open-Radio Access Network, O-RAN, architecture, comprising the step of configuring the at least one RU node by means of at least one of a near-real-time RAN Intelligent Controller, RIC, and a non-real-time RIC.

2. The method of claim 1 wherein an xApp is provided in the near-real-time RIC or an rApp is provided in the non-real-time RIC.

3. The method of claim 2 wherein an Artificial Intelligence / Machine Learning, AI / ML, model is deployed as or within an xApp instance4. The method of claim 3 wherein the AI / ML model is arranged to be updated via an xApp software update.

5. The method of claim 1 or 2 wherein an AI / ML model is decoupled from an xApp and is arranged to be enabled or updated via an xApp file configuration.

6. The method of any preceding claim wherein an O-RAN Network Function, NF, is arranged to be managed via an O1 interface and an authorised service orchestration and management, SMO, framework and, additionally, a further interface is provided whereby the O-RU functionality may be controlled directly from near-real-time RIC.

7. The method of any of claims to 6 wherein a control model is provided which allows the configuration of the O-RU according to actions from the xApp or rApp.

8. The method of any preceding claim wherein an interface is provided between the O-RU and one or more of the near-real-time RIC and the non-real-time RIC, wherein the interface comprises at least one of: a list of IDs of certain O-RU components to be configured; and certain parameters of the O-RU to be configured.

9. The method of claim 8 wherein the certain parameters comprise one or more of antenna tilt and ADC quantisation level.

10. The method of claim 8 or 9 wherein the interface is arranged to acknowledge completionof actions from the O-RU to the near-real-time RIC or the non-real-time RIC.

11. The method of claim 10 wherein the O-RU is arranged to report update of parameters after an action is taken.

12. Apparatus arranged to perform the method of any preceding claim.

Images