Radio access fronthaul operation

Abstract

A technique for operating the fronthaul of a radio access network is described. As to one method (300) aspect of the technique performed by a RAN entity (100; 1012) of a radio access network, RAN (500), transport-related telemetry information indicative of telemetry of the transport domain (550) is received (306) from at least one transport node (200) of a transport domain (550) of the RAN (500).

Description

[0001] Telefonaktiebolaget LM Ericsson (publ) 1 / 62 301-0276WO P111758WO01 13 Dec 2024

[0002] Radio access fronthaul operation

[0003] Technical Field

[0004] The present disclosure relates to a technique for operating a fronthaul in radio access networks. More specifically, and without limitation, methods and devices for receiving transport-related telemetry information and sending such information are provided.

[0005] Background

[0006] The evolution of mobile networks through the Third Generation Partnership Project (3GPP) and the O-RAN Alliance has driven significant advancements in radio access network (RAN) technology. These developments aim to enhance network efficiency, flexibility, and interoperability among different network components. Innovations in 5G and beyond have introduced new challenges and opportunities in the management and operation of the fronthaul, which connects radio units with digital units.

[0007] In this context, the need for efficient data transport and quality assurance in the fronthaul becomes paramount. While a packet-switched fronthaul comes with flexibility, the RAN should not lose control over network performance, in order to optimize resource allocation and to ensure compliance with quality of service (QoS) requirements. These capabilities are crucial for maintaining reliable and high-quality network services.

[0008] However, existing packet-switched fronthaul networks lack mechanisms for comprehensive control of data packet transport in the RAN. This limitation impedes the ability of the RAN to differentiate between transport network issues and radio interface issues, hindering effective network operation.

[0009] Summary

[0010] Accordingly, there is a need for a fronthaul operation technique that enables RAN entities to supervise transport data packets to improve network performance. Telefonaktiebolaget LM Ericsson (publ) 2 / 62 301-0276WO

[0011] P111758WO01 13 Dec 2024

[0012] As to a first method aspect, a method performed by a RAN entity of a radio access network (RAN) is provided. The method includes receiving transport-related telemetry information from at least one transport node of a transport domain of the RAN. The telemetry information is indicative of telemetry (e.g., performance characteristics) of the transport domain.

[0013] By enabling the RAN entity to receive transport-related telemetry information, the method allows the RAN to differentiate between issues of the transport network and those of the radio interface. This differentiation facilitates corrective actions and optimizations, improving overall RAN performance and ensuring efficient use of network resources.

[0014] As to a second method aspect, a method performed by a transport node in a transport domain of a radio access network (RAN) is provided. The method includes sending transport-related telemetry information to at least one RAN entity of the RAN. The telemetry information is indicative of telemetry (e.g., performance characteristics) of the transport domain.

[0015] By providing transport-related telemetry information to RAN entities, the method ensures that RAN nodes can access critical performance data. This access supports informed decision-making, enhances network management, and enables timely adjustments to maintain optimal network operation.

[0016] The first and second method aspect may further comprise any feature or step disclosed herein. Whenever a feature or step is described from the perspective of the RAN entity, the skilled person understands that this may imply a corresponding feature or mirrored step at the transport node. The same is true vice versa for a corresponding feature or mirrored step at the RAN entity based on a description of the transport node.

[0017] In any aspect and any embodiment, the transport-related telemetry information may differentiate between different flows. For example, the transport-related telemetry information may comprise different telemetry values in association with different flow labels. Based on the flow-specific feedback, i.e., the received transport-related telemetry information, the RAN entity may (e.g., indirectly) control transport of data packets in the transport domain by including Telefonaktiebolaget LM Ericsson (publ) 3 / 62 301-0276WO

[0018] P111758WO01 13 Dec 2024 corresponding flow labels in a (e.g., network or transport) header of the data packets.

[0019] Embodiments of the first or second method aspect may comply with, or may enhance, at least one of the technical standards O-RAN Control, User and Synchronization Plane Specification 16.01; evolved Common Public Radio Interface, eCPRI, Version 2.0; O-RAN Xhaul Packet Switched Architectures and Solutions 8.0; RFC 8972; and RFC 8986.

[0020] For example, the protocols defined in the O-RAN Control, User and Synchronization Plane Specification (e.g., version 16.01) may be applied for efficient telemetry data exchange between Radio Units (RUs) and Distributed Units (DUs), as examples of the RAN entity, over the fronthaul interface. The specification outlines the control and user plane operations, which may facilitate the integration of the telemetry interworking function (TIWF) according to the second method aspect to ensure seamless transport of the telemetry information across the O-RAN architecture. The defined latency and synchronization requirements may guide the implementation of real-time telemetry data processing and / or transmission, e.g., enhancing the overall performance and reliability of the RAN.

[0021] Furthermore, the evolved Common Public Radio Interface (eCPRI, Version 2.0) may be relevant to the first and second method aspects by providing a framework for packet-based transport of user plane data between RAN entities. The eCPRI specification supports flexible functional splits, which may be utilized to implement the TIWF functionality within the fronthaul of the RAN. By adhering to the eCPRI message formats and protocols, the method aspects may achieve efficient telemetry data encapsulation and transport, enabling precise monitoring and management of RAN performance.

[0022] The transport domain may use the O-RAN Xhaul Packet Switched Architectures and Solutions (e.g., version 8.0) for the packet-switched transport mechanisms that underpin the first and second method aspects. This document may be used for segment routing over IPv6 (SRv6) for traffic engineering (e.g., transport control) based on the transport-related telemetry information provided to the RAN entity within the fronthaul. Alternatively or in addition, the document's focus on end-to- end packet switching technology may inform an implementation of robust Telefonaktiebolaget LM Ericsson (publ) 4 / 62 301-0276WO P111758WO01 13 Dec 2024 telemetry data paths, ensuring that telemetry information is accurately collected and disseminated across the RAN.

[0023] RFC 8972 introduces the Simple Two-Way Active Measurement Protocol (STAMP) extensions, which may be applied to the second method aspect by providing a standardized method for active measurement of telemetry (e.g., network performance metrics) such as latency and packet loss. By incorporating type- length-value (TLVs) for the STAMP, the method aspects may enhance telemetry capabilities, enabling detailed performance assessments and facilitating the identification of network issues, thereby improving RAN optimization strategies.

[0024] RFC 8986 as well as Compressed SRv6 Segment List Encoding (CSID) describes Segment Routing over IPv6 (SRv6), e.g., within a Network Programming framework, which may be utilized in the first and second method aspects to specify packet processing instructions for transport-related telemetry information flows. The use of SRv6 allows for precise traffic engineering, i.e., transport path selection, e.g., for the effective operation of the TIWF. By using SRv6's ability for the transport node to encode a sequence of instructions within the IPv6 header, the second method aspect may achieve efficient and scalable transport of the telemetry information, optimizing the RAN's operational performance.

[0025] The Compressed SRv6 Segment List Encoding (CSID), e.g. as described in the latest draft (draft-ietf-spring-srv6-srh-compression-19), can be applied to the first and second method aspects. By utilizing CSID, embodiments of the first and second method aspects can benefit from a reduced overhead in the SRv6 headers, enabling more efficient encoding of segment lists within the IPv6 packets used for transporting the telemetry information. This compression allows for more scalable and resource-efficient transport of the telemetry information, enhancing the operation of the Telemetry Interworking Function (TIWF) and optimizing the overall performance of the RAN by facilitating precise traffic engineering with minimal packet header overhead.

[0026] The RAN (e.g., the RAN entity) may serve one or more radio devices. Any radio device may be a user equipment (UE), e.g., according to a 3GPP specification. The radio device and the RAN may be wirelessly connected in an uplink (UL) and / or a downlink (DL) through a Uu interface. Telefonaktiebolaget LM Ericsson (publ) 5 / 62 301-0276WO

[0027] P111758WO01 13 Dec 2024

[0028] The radio device and / or one or more embodiments of the RAN entity and / or one or more embodiments of the transport node may form, or may be part of, a radio network, e.g., according to the Third Generation Partnership Project (3GPP) or according to the standard family IEEE 802.11 (Wi-Fi). The first method aspect and the second method aspect may be performed by one or more embodiments of the RAN entity and the transport node, respectively.

[0029] The RAN entity may be a network node (e.g., a base station) or a functional part thereof, e.g., a radio unit (RU) or a digital unit (DU), e.g. a baseband unit (BBU). The transport node may be a router in the transport domain of the RAN. Multiple RAN entities of the RAN (e.g., at least one or each of which entities may be an embodiment of the RAN entity of the subject technique) may be connected through the transport domain and / or the transport node. A physical layer or medium access control (MAC) layer of the transport domain may comprise wired Ethernet or Ethernet over microwave.

[0030] Furthermore, the RAN entity may be connected (e.g., through to the transport domain) with a centralized unit (CU) for base station functionality.

[0031] The RAN may comprise one or more base stations or combinations of RUs and DUs for distributed multiple-input multiple-output (D-MIMO). The base stations, RUs, and / or DUs may be performing the first method aspect. Alternatively or in addition, the radio network may be a vehicular, ad hoc and / or mesh network comprising two or more radio devices, e.g., acting as a remote radio device and / or a relay radio device in device-to-device communication.

[0032] Any of the radio devices may be a 3GPP user equipment (UE) or a Wi-Fi station (STA). The radio device may be a mobile or portable station, a device for machinetype communication (MTC), a device for narrowband Internet of Things (NB-loT) or a combination thereof. Examples for the UE and the mobile station include a mobile phone, a tablet computer and a self-driving vehicle. Examples for the portable station include a laptop computer and a television set. Examples for the MTC device or the NB-loT device include robots, sensors and / or actuators, e.g., in manufacturing, automotive communication and home automation. The MTC device or the NB-loT device may be implemented in a manufacturing plant, household appliances and consumer electronics. Telefonaktiebolaget LM Ericsson (publ) 6 / 62 301-0276WO

[0033] P111758WO01 13 Dec 2024

[0034] The RAN entity (e.g., a base station of a functional part thereof) may encompass any station that is configured to provide, or assist in, radio access to any of the radio devices. The RAN entity may be associated to a cell, a transmission and reception point (TRP), a central unit (CU), a distributed unit (DU), a radio access node or an access point (AP). The RAN entity and / or the transport node may provide a data link to a host computer, e.g., providing user data to the radio device or gathering user data from the radio device. Examples for the base station functionality may include a 3G base station or Node B (NB), 4G base station or eNodeB (eNB), a 5G base station or gNodeB (gNB), a Wi-Fi AP and a network controller (e.g., according to Bluetooth, ZigBee or Z-Wave).

[0035] The RAN may be implemented according to 3GPP Long Term Evolution (LTE), 3GPP New Radio (NR), or beyond 5G.

[0036] Embodiments of the first and second method aspect may be implemented at a Network Layer (Layer 3). For example, the transport node may operate at the network layer by routing packets using IP addresses and managing the transport paths through which data packets of the RAN traffic travel. The telemetry interworking function (TIWF) may collect telemetry information at this layer, which may be crucial for understanding and optimizing the transport paths (e.g., the routing paths) within the transport domain. Alternatively or in addition, Segment Routing over IPv6 (SRv6) may be employed at this layer, impacting how data packets are encapsulated and routed in the transport domain depending on the transport-related telemetry information.

[0037] Although primarily focused on the network layer, some embodiments may be present at a Transport Layer (Layer 4) in terms of how the transport-related telemetry information influences congestion control and / or flow management. For example, the received telemetry information may provide insights into packet loss rates and latency, which are processed by a transport protocol that ensures reliable delivery or any other compliance with QoS requirements.

[0038] While the primary focus is on higher layers, some embodiments may relate to a Data Link Layer (Layer 2) indirectly affected by adjustments responsive to the received telemetry information. For example, understanding latency and / or jitter at the network layer may trigger to configurations at the data link layer to improve forwarding of the data packets. Telefonaktiebolaget LM Ericsson (publ) 7 / 62 301-0276WO

[0039] P111758WO01 13 Dec 2024

[0040] The TIWF may be implemented at an Application Layer (Layer 7) of the transport node. For example, the TIWF may process collected telemetry data and / or send the resulting telemetry information to one or more RAN entities as application payload. Thus, the application layer can make the telemetry information accessible at the RAN.

[0041] Herein, referring to a protocol of a layer may also refer to the corresponding layer in the protocol stack. Vice versa, referring to a layer of the protocol stack may also refer to the corresponding protocol of the layer. Any protocol may be implemented by a corresponding method, e.g., the first or second method aspect or a step thereof.

[0042] As to another aspect, a computer program product is provided. The computer program product comprises program code portions for performing any one of the steps of the first and / or second method aspects disclosed herein when the computer program product is executed by one or more computing devices. The computer program product may be stored on a computer-readable recording medium. The computer program product may also be provided for download, e.g., via the radio network, the RAN, the Internet and / or the host computer.

[0043] Alternatively, or in addition, the method may be encoded in a Field-Programmable Gate Array (FPGA) and / or an Application-Specific Integrated Circuit (ASIC), or the functionality may be provided for download by means of a hardware description language.

[0044] As to a first device aspect, a RAN entity is provided. The RAN entity comprises processing circuitry (e.g., at least one processor and a memory). Said memory comprises instructions executable by said at least one processor whereby the device is operative to perform any one of the steps of the first method aspect.

[0045] As to another first device aspect, a RAN entity is provided. The RAN entity is configured to perform any one of the steps of the first method aspect.

[0046] As to a second device aspect, a transport node is provided. The transport node comprises processing circuitry (e.g., at least one processor and a memory). Said memory comprises instructions executable by said at least one processor whereby Telefonaktiebolaget LM Ericsson (publ) 8 / 62 301-0276WO

[0047] P111758WO01 13 Dec 2024 the device is operative to perform any one of the steps of the second method aspect.

[0048] As to another second device aspect, a transport node is provided. The transport node is configured to perform any one of the steps of the second method aspect.

[0049] As to a further aspect, a communication system comprising at least one RAN entity according to the first device aspect and comprising at least one transport node according to the second device aspect is provided. For example, the communication system comprises multiple RAN entities connected by one or more transport domains. The at least one transport nodes may comprise all routers within the transport domain or all routers at the edge of the transport domain.

[0050] As to a still further aspect, a communication system including a host computer is provided. The host computer comprises a processing circuitry configured to provide user data, e.g., included in the RAN traffic transported, through the transport domain according to the first and / or second method aspect. The host computer further comprises a communication interface configured to forward the user data to a cellular or D-MIMO network (e.g., the RAN and / or the RAN entity) for transmission to a radio device. A processing circuitry of the RAN is configured to execute any one of the steps of the first and / or second method aspects.

[0051] The communication system may further include the radio device. Alternatively, or in addition, the cellular or D-MIMO network may further include one or more RAN entities (e.g., embodying the first device aspect) and / or one or more transport nodes (e.g., embodying the second device aspect), optionally configured for radio communication with the radio device and / or to provide a data link between the radio device and the host computer using the first and / or second method aspects.

[0052] The processing circuitry of the host computer may be configured to execute a host application, thereby providing the user data and / or any host computer functionality described herein. Alternatively, or in addition, the processing circuitry of the radio device may be configured to execute a client application associated with the host application.

[0053] Any one of the devices, the UE, the base station, the communication system or any node or station for embodying the technique may further include any feature Telefonaktiebolaget LM Ericsson (publ) 9 / 62 301-0276WO

[0054] P111758WO01 13 Dec 2024 disclosed in the context of the method aspect, and vice versa. Particularly, any one of the units and modules disclosed herein may be configured to perform or initiate one or more of the steps of the method aspect.

[0055] Brief Description of the Drawings

[0056] Further details of embodiments of the technique are described with reference to the enclosed drawings, wherein:

[0057] Fig. 1 shows a schematic block diagram of an embodiment of a RAN entity with modules for requesting and receiving telemetry, illustrating examples of Telemetry Interworking Function (TIWF) consumer components.

[0058] Fig. 2 shows a schematic block diagram of an embodiment of a transport node with modules for collecting and sending telemetry, illustrating examples of TIWF producer components.

[0059] Fig. 3 illustrates a flowchart for an embodiment of a method of operating a radio access fronthaul, which method may be performed by the RAN entity of Fig. 1 to receive transport-related telemetry information from a transport node.

[0060] Fig. 4 illustrates a flowchart for an embodiment of a method of operating a radio access fronthaul, which method may be performed by the transport node of Fig. 2 to collect telemetry information and send it to a RAN entity in response to a telemetry request.

[0061] Fig. 5 depicts an example of fronthaul of a radio access network with multiple RAN entities and transport nodes, which may embody the devices of Figs. 1 and 2, respectively, interconnected for exchanging telemetry information across the fronthaul according to the methods of Figs. 3 and 4.

[0062] Fig. 6 schematically represents an example of a transport domain transport nodes, which are between RAN entities, exemplifying a region of transport telemetry that can become accessible by embodiments using the devices of Figs. 1 and 2 performing the methods of Figs. 3 and 4, respectively. Telefonaktiebolaget LM Ericsson (publ) 10 / 62 301-0276WO P111758WO01 13 Dec 2024

[0063] Fig. 7 schematically illustrates the transmission of telemetry information packets from a transport domain to a RAN entity outside of the transport domain.

[0064] Fig. 8 shows a block diagram of a detailed embodiment of the RAN entity of Fig. 1.

[0065] Fig. 9 shows a block diagram of a detailed embodiment of the transport node of Fig. 2.

[0066] Fig. 10 shows an example of a communication system including a telecommunication network and optional components outside of the telecommunication network for illustrating an example location of the RAN and its transport domain within such a system.

[0067] Detailed Description

[0068] In the following description, for purposes of explanation and not limitation, specific details are set forth, such as a specific network environment in order to provide a thorough understanding of the technique disclosed herein. It will be apparent to one skilled in the art that the technique may be practiced in other embodiments that depart from these specific details. Moreover, while the following embodiments are primarily described for a New Radio (NR) or 5G implementation, it is readily apparent that the technique described herein may also be implemented for any other radio communication technique, including future generations and a Wireless Local Area Network (WLAN) implementation according to the standard family IEEE 802.11, 3GPP LTE (e.g., LTE-Advanced or a related radio access technique such as MulteFire), for Bluetooth according to the Bluetooth Special Interest Group (SIG), particularly Bluetooth Low Energy, Bluetooth Mesh Networking and Bluetooth broadcasting, for Z-Wave according to the Z-Wave Alliance or for ZigBee based on IEEE 802.15.4.

[0069] Moreover, those skilled in the art will appreciate that the functions, steps, units and modules explained herein may be implemented using software functioning in conjunction with a programmed microprocessor, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a Digital Signal Processor (DSP) or a general-purpose computer, e.g., including an Advanced RISC Machine (ARM). It will also be appreciated that, while the following embodiments are Telefonaktiebolaget LM Ericsson (publ) 11 / 62 301-0276WO

[0070] P111758WO01 13 Dec 2024 primarily described in context with methods and devices, the invention may also be embodied in a computer program product as well as in a system comprising at least one computer processor and memory coupled to the at least one processor, wherein the memory is encoded with one or more programs that may perform the functions and steps or implement the units and modules disclosed herein.

[0071] Fig. 1 illustrates a schematic block diagram of an embodiment of a RAN entity 100, which functions as a Telemetry Interworking Function (TIWF) consumer 101 within a radio access network (RAN). The RAN entity 100 is configured to receive transport-related telemetry information from a transport node of the transport domain, thus enabling it to differentiate issues of the transport network from those of the radio interface and improve overall RAN performance.

[0072] The RAN entity 100 includes a telemetry receiving module 106, which is responsible for receiving transport-related telemetry information from at least one transport node in the transport domain. This telemetry information is indicative of the performance characteristics of the transport domain, allowing the RAN entity 100 to make informed decisions regarding network management and optimization.

[0073] Optionally, the RAN entity 100 comprises a telemetry requesting module 104. This module facilitates the sending of telemetry requests to the transport node, enabling the RAN entity 100 to retrieve transport-related telemetry information on-demand. The telemetry requesting module 104 supports the RAN entity's ability to efficiently respond to changing network conditions by selectively requesting telemetry data pertinent to specific transport paths.

[0074] The functional relationship between these modules is that the telemetry requesting module 104, if present, allows the RAN entity 100 to actively request telemetry data, while the telemetry receiving module 106 processes the incoming telemetry information. This interplay ensures that the RAN entity 100 can dynamically adjust its operations based on real-time transport network performance metrics.

[0075] The RAN entity 100, through these components, participates in a method of operating a radio access fronthaul by receiving telemetry information, potentially requesting such information, and utilizing it to enhance network performance. This embodiment supports the first method aspect of the invention, where a RAN Telefonaktiebolaget LM Ericsson (publ) 12 / 62 301-0276WO

[0076] P111758WO01 13 Dec 2024 entity supervises data packet transport to improve network performance by receiving and optionally requesting transport-related telemetry information. Any of the modules of the device 100 may be implemented by units configured to provide the corresponding functionality.

[0077] The RAN entity 100 may also be referred to as, or may be embodied by, a base station, baseband unit (BBU) or any other RAN node, such as radio unit (RU), digital unit (DU), or central unit (CU). The RAN entity 100 and the transport node may be in direct (e.g., wired or microwave or free-space optical) communication, e.g., at least for the reception of the telemetry information from the transport node at the RAN entity 100. The transport node may be embodied by the following device 200.

[0078] Fig. 2 illustrates an embodiment of a transport node 200 within a radio access network (RAN), specifically functioning as a Telemetry Interworking Function (TIWF) producer 201. The transport node 200 is configured to collect and send transport-related telemetry information to one or more RAN entities. This functionality supports the second method aspect, enabling effective communication and monitoring within the transport domain of the RAN.

[0079] The transport node 200 includes a telemetry sending module 206, responsible for sending transport-related telemetry information to at least one RAN entity. This module ensures that the RAN nodes receive critical performance data, facilitating informed decision-making and enhancing network management. The telemetry sending module 206 plays a crucial role in maintaining the optimal operation of the RAN by providing timely telemetry updates based on the collected telemetry information.

[0080] Optionally, the transport node 200 comprises a telemetry collecting module 202, which is responsible for gathering telemetry data from the transport domain. This optional module enables the transport node to monitor performance characteristics, ensuring that detailed and accurate telemetry information is available for dissemination to RAN entities 100. The telemetry collecting module 202 supports the method by enabling the collection of comprehensive telemetry data pertinent to the transport domain.

[0081] The functional relationship between these modules ensures that the transport node 200 operates efficiently as a TIWF producer 201. The telemetry collecting Telefonaktiebolaget LM Ericsson (publ) 13 / 62 301-0276WO

[0082] P111758WO01 13 Dec 2024 module 202, if present, gathers necessary transport-related telemetry information, which is then processed and sent (e.g., broadcast) by the telemetry sending module 206. This interplay guarantees that the RAN receives accurate and relevant telemetry information, supporting effective network management and optimization.

[0083] Overall, the transport node 200, through its modules, participates in a method of operating a radio access fronthaul by collecting and sending transport-related telemetry information, thereby enhancing the RAN's ability to supervise and optimize data packet transport. This embodiment supports the second method aspect of the invention, wherein a transport node communicates essential telemetry information to improve network performance.

[0084] Any of the modules of the device 200 may be implemented by units configured to provide the corresponding functionality.

[0085] The transport node 200 may also be referred to as, or may be embodied by, a router or gateway. The transport node 200 and the RAN entity may be in (e.g., direct wireless or wired) communication, e.g., at least for the sending of the telemetry information from the transport node 200 to the RAN entity. The RAN entity may be embodied by the above device 100.

[0086] Fig. 3 illustrates an embodiment of a method 300 performed by a RAN entity 100 of a radio access network (RAN) for operating a fronthaul of the RAN.

[0087] The method shown in Fig. 3 focuses on the reception, and optionally, utilization of transport-related telemetry information in the operation of the RAN fronthaul. Embodiments of the method 300 can enhance the RAN's ability to monitor and / or optimize RAN fronthaul performance by receiving critical telemetry data from a transport domain.

[0088] In a step 306 of the method 300, the RAN entity 100 receives transport-related telemetry information from at least one transport node 200 within a transport domain of the RAN. This telemetry information is indicative of the telemetry, i.e. performance characteristics, of the transport domain. The received telemetry information can allow the RAN entity 100 to differentiate between issues related to the transport network and those related to the radio interface. Alternatively or Telefonaktiebolaget LM Ericsson (publ) 14 / 62 301-0276WO

[0089] P111758WO01 13 Dec 2024 in addition, the received telemetry information can allow the RAN entity 100 to differentiate between alternative transport paths within the transport domain.

[0090] Optionally, in the step 304 of the method 300, the RAN entity 100 may send a telemetry request to the transport node 200. This request enables the RAN entity to actively retrieve transport-related telemetry information on demand, enhancing its ability to respond to dynamic network conditions by requesting telemetry, e.g. specific data pertinent to one or more individual transport paths within the transport domain.

[0091] Another optional step 302 is the sending of a configuration message by the RAN entity 100 to the transport node 200. This configuration message configures a Telemetry Interworking Function (TIWF) at the transport node, instructing it to collect and subsequently send the transport-related telemetry information to the RAN entity 100. This step can ensure that the telemetry data is collected and disseminated in a manner aligned with the RAN's operational needs, e.g. quality of service (QoS) requirements for one or more individual RAN flows.

[0092] In optional step 308, based on the received transport-related telemetry information, the RAN entity 100 may change at least one operational parameter of either the RAN entity 100 itself or may change (e.g., indirectly) the operation of the transport node, e.g. by changing an input parameter for the transport node to use when adapting transport parameters of the transport node 200. This change enables the RAN entity 100 to optimize network resources, adjust traffic flows, and / or maintain or enhance the QoS within the RAN, thereby improving overall RAN performance.

[0093] The functional relationship between these steps ensures that the RAN entity 100 can dynamically manage its operations based on real-time telemetry data, allowing for precise control and optimization of network resources. The method 300 thus supports the first method aspect of the invention, enabling effective supervision and enhancement of data packet transport within the RAN.

[0094] The method 300 may be performed by the RAN entity 100 of Fig. 1. For example, modules 102, 104, 106, and 108 of the RAN entity 100 may perform the steps 302, 304, 306, and 308, respectively. Telefonaktiebolaget LM Ericsson (publ) 15 / 62 301-0276WO

[0095] P111758WO01 13 Dec 2024

[0096] Fig. 4 illustrates a schematic flowchart of an embodiment of a method 400 performed by a transport node 200 within a transport domain of a radio access network (RAN). The method focuses on the collection and dissemination of transport-related telemetry information, which is essential for optimizing the operation of the RAN fronthaul.

[0097] In optional step 402, the transport node 200, equipped with a telemetry interworking function (TIWF) 201, may collect transport-related telemetry information from the transport domain. This information is indicative of the telemetry of the transport domain, providing insights into the performance characteristics such as latency, packet loss, and / or jitter. The collection of this telemetry data allows the transport node 200 to prepare valuable information for RAN entities 100, enabling them to enhance network management.

[0098] Step 404, which is also optional, involves the transport node 200 receiving a telemetry request from at least one RAN entity 100 within the RAN 500. This request prompts the transport node to gather specific telemetry data as required by the RAN entity. The ability to respond to telemetry requests ensures that the transport node 200 can provide timely and relevant telemetry information, aiding in the dynamic optimization of network resources.

[0099] In step 406, the transport node 200 sends the collected transport-related telemetry information (optionally after processing, e.g. filtering for specifically requested transport paths or flow labels) to at least one RAN entity 100 of the RAN. This step is crucial for ensuring that RAN entities have access to up-to-date performance metrics of the transport domain, facilitating informed decisionmaking and enhancing the overall performance of the RAN. The dissemination of telemetry data supports the RAN in maintaining quality of service and optimizing resource allocation.

[0100] Step 408, which is optional, involves changing at least one operational parameter of the transport node 200 based on the received transport-related telemetry information. This change can include adjustments to routing paths or traffic management strategies, ensuring that the transport domain operates efficiently and in alignment with the RAN's requirements. The option to adapt operational parameters based on telemetry data is vital for maintaining optimal network performance. This can implement a closed-loop control, e.g. either within the Telefonaktiebolaget LM Ericsson (publ) 16 / 62 301-0276WO

[0101] P111758WO01 13 Dec 2024 transport node 200 or through the feedback represented by the telemetry information sent to the RAN entity 100 and the control message received from the RAN entity 100 in response to the feedback.

[0102] The functional relationship between these steps ensures that the transport node 200 can effectively collect, process, and distribute telemetry information, thereby playing a critical role in the supervision and enhancement of data packet transport within the RAN. This embodiment supports the second method aspect of the invention, enabling the transport node to facilitate improved network performance through telemetry data management.

[0103] The method 400 may be performed by the device 200. For example, the transport node may comprise modules 202, 204, 206, and 208 performing the steps 402, 404, 406, and 408, respectively.

[0104] Herein, "predefined" may encompass stored in memory of any device aspect, or hard-coded or hard-wired in any device aspect, or preconfigured or configured by a network node of the radio access network (RAN) or a core network (CN) serving the RAN. Furthermore, a list of the form A, B, and / or C (also written as A, B and / or C) may correspond to at least one or each of A, B, and C, i.e., A and / or B and / or C.

[0105] Embodiments of the first aspect, i.e., the method 300 and the device 100 referred to as RAN entity, may be implemented at any functional or structural entity of a radio access networks (RAN) 500. Moreover, embodiments of the second aspect, i.e., the method 400 and the device 200 referred to as transport node, enable a RAN-aware Telemetry Interworking Function (i.e., TIWF 201) for a packet-switched fronthaul of the RAN 500, e.g., an IP-based fronthaul.

[0106] Fig. 5 schematically illustrates an example of a fronthaul of a RAN 500. The RAN 500 provides radio connectivity for mobile devices, i.e., radio devices. The RAN 500 for mobile telecommunication undergoes a significant transformation in the fifth generation (5G) and the sixth generation (6G) of radio access technology (RAT). For data transport within the RAN 500, one of the major changes is the usage of packet-based connectivity between RAN entities 100, e.g., RAN components such as a radio unit (RU) and a digital unit (DU), which connectivity and components are collectively referred to as fronthaul (FH). Due to the Telefonaktiebolaget LM Ericsson (publ) 17 / 62 301-0276WO

[0107] P111758WO01 13 Dec 2024 increased traffic volume between the RAN entities 100, sharing transport-related telemetry information with RAN entities 100 (e.g., RAN nodes) in packet-based FH networks becomes an essential functionality.

[0108] Herein, the RU may be a remote radio head (RRH) or remote radio unit (RRU). The DU may be a baseband unit (BBU). Alternatively or in addition, the DU may be a distributed unit of a base station, wherein "distributed" may refer to the role of DUs in providing time-critical base station functionality in proximity to the RRH / RRU or mobile devices. The DU may be further connected and served by a centralized unit (CU) of a base station, which portion of the RAN is also referred to as midhaul (MH). A backhaul (BH) may connect the RAN to a core network (CN). Moreover, any functionality of the DU and / or CU, as disclosed herein, may be performed by remote computing resources and / or may be accessed via internet protocols (e.g., for a Cloud RAN implementation). The functionality of the DU and CU may be referred to as virtual DU (vDU) and virtual CU (vCU), respectively.

[0109] The present disclosure provides an FH-specific telemetry interworking functionality 201 that enables telemetry-related interaction between the RAN 500 and the transport domain 550, e.g., between RAN entities 100 and routers (as examples of the transport node 200) in the transport domain 550 of the RAN. (The term interworking may also be written with capitalization as "InterWorking" or hyphenation as "inter-working".)

[0110] In any embodiment, transport and transport domain 550 in the fronthaul of the RAN 500 may relate to a Layer 3 (L3) network, e.g., an internet protocol (IP) network, which uses routing as a forwarding paradigm.

[0111] The fronthaul (FH) of the RAN 500 requires traffic engineering capabilities, e.g., in order to assure at least one of bandwidth, maximum delay and variance of the delay, to satisfy Quality of Service (QoS) requirements for RAN flows of the RAN 500. This can be ensured by traffic steering capabilities, e.g., using Segment Routing (SR) over IPv6 (SRv6) in IP-based FH networks. SRv6 is a form of tunneling technology, wherein one or more data packets, which are ultimately sent and received between RAN entities 100, are encapsulated in a packet according to the internet protocol (IP) version 6 (IPv6), and the traffic steering information is Telefonaktiebolaget LM Ericsson (publ) 18 / 62 301-0276WO

[0112] P111758WO01 13 Dec 2024 encoded in the outer IPv6 header and / or in a Segment Routing Header (SRH) extension header.

[0113] Routing is about where to send data packets, i.e., path selection and forwarding. Transport is about how to send data packets, e.g., reliably and in compliance with the QoS requirements. Controlling the routing may be part of the transport.

[0114] During communication between RAN entities 100, the RAN entities 100 may need transport-related telemetry information (briefly: telemetry information or telemetry data) regarding one or more RAN flows of the RAN 500, e.g., a transport-specific packet loss rate. However, the existing transport uses SRv6 tunneling, and the tunnel-related telemetry information is terminated at tunnel endpoints (TEPs) within the transport domain 550. Therefore, transport-specific telemetry is not available for entities (e.g., nodes) outside of the transport domain 550, i.e., for the RAN entities 100.

[0115] Examples of the transport-related telemetry information (briefly: telemetry information) include:

[0116] (1) packet loss, e.g., a rate (i.e., losses per time) or a fraction (i.e., percentage of lost packets relative to the total packets transmitted);

[0117] (2) packet latency, e.g., a measure of time delay from an ingress point (entry) to an egress point (exit), optionally reported as average latency, maximum latency, or latency percentiles; and

[0118] (3) jitter, e.g., a variability in latency, often represented as the standard deviation or variance in latency or packet delays.

[0119] Fig. 5 schematically illustrates an internet protocol (IP) FH network scenario. The nodes labelled R (such as R1 and R3) in Fig. 5 comprise routers, which are examples of the transport node 200, in the context of the transport network, i.e., the transport domain 550.

[0120] Fig. 5 schematically show an example of a FH of a RAN 500. The transport domain 550 may comprise one or more transport tunnels. Some or each of the tunnels may be unidirectional. For a bidirectional data connection between two routers R2 and R4 (as examples of the transport nodes 200), the transport domain 550 Telefonaktiebolaget LM Ericsson (publ) 19 / 62 301-0276WO

[0121] P111758WO01 13 Dec 2024 may comprise two transport tunnels in opposite directions between these routers R2 and R4.

[0122] Furthermore, as indicated in Fig. 5, Radio Units (RUs), which are examples of the RAN entity 100, are connected to the routers.

[0123] A first method aspect relates to a method performed by a RAN entity of a radio access network (RAN). The method comprises receiving, from at least one transport node of a transport domain of the RAN, transport-related telemetry information indicative of telemetry of the transport domain.

[0124] By receiving transport-related telemetry information from the transport domain, the RAN entity gains access to performance characteristics of the transport domain, which may had been previously unavailable to RAN entities. Embodiments enable the RAN entity to differentiate issues of a transport network (i.e., the transport domain) from issues of a radio interface of the RAN, e.g., to perform corrective actions (e.g., changing transport parameters of a network configuration of the transport domain), thereby improving RAN performance.

[0125] The transport-related telemetry information indicative of telemetry may comprise at least one telemetry value, e.g., a performance value, that enables the RAN entity to determine whether transport in the transport domain meets a requirement of the RAN.

[0126] In an embodiment, the transport node may be configured to perform a protocol of a network layer and / or a transport layer within the transport domain. Alternatively or in addition, the transport node may operate outside of a radio protocol stack of the RAN. Alternatively or in addition, the RAN entity may perform a protocol of a radio protocol stack of the RAN. Alternatively or in addition, the RAN entity may operate outside the transport domain.

[0127] The transport node in the fronthaul of the RAN may be a functional component in a network layer and / or a transport layer that ensures seamless delivery of RAN-specific traffic. Preferably, the transport node is not, in itself, a functional component of the RAN. The transport node may be arranged and configured to transport data packets, e.g., including Control Plane (CP), User Plane (UP), and Telefonaktiebolaget LM Ericsson (publ) 20 / 62 301-0276WO

[0128] P111758WO01 13 Dec 2024

[0129] Synchronization Plane (SP) traffic, across a transport network underlying the RAN. The transport node may perform at least one of encapsulation, forwarding, and termination of transport-layer packets, e.g., focusing solely on efficient delivery rather than interacting with the protocol stack of the RAN.

[0130] The transport node may perform the transport without interpreting or processing RAN-specific protocols or layers. The transport node may be agnostic to a functional architecture of the RAN. Alternatively or in addition, the transport node may be transparent for the traffic of the RAN (e.g. for the CP, UP, and / or SP traffic of the RAN).

[0131] In contrast, the RAN entity performing the first method aspect may be a functional component of the RAN. Alternatively or in addition, the radio protocol stack (which protocol is performed by the RAN entity and / or is not performed by the transport node) may comprise (e.g., exclusively) at least one of: a radio resource control (RRC) layer, the CP and / or UP of a packet data convergence protocol (PDCP) layer, a Radio Link Control (RLC) layer, a Medium Access Control (MAC) layer, and physical layer (PHY).

[0132] In a variant of any embodiment (e.g., while the transport node does not take part in, i.e. perform, RAN protocols and / or the RAN entity does not take part, i.e. perform transport and / or routing, in the transport domain), the RAN entity may label (also: "mark") data packets to be transported by the transport domain (i.e., RAN traffic) within transport protocol headers. For example, the labeled transport protocol header may control (e.g., enable or instruct) the transport node (or another transport node in the transport domain) to differentiate RAN flows on transport protocol layers or to process the data packet in accordance with a RAN flow associated with the data packet based on the transport protocol layer header. In other words, the RAN entity (e.g., while being physically outside of the transport domain) may indirectly control the transport in the transport domain by labeling.

[0133] Embodiments of the method enable feedback (i.e., the transport-related telemetry information) for (e.g., closed-loop) controlling of the transport (i.e., of the transport domain). In other words, the transport-related telemetry information is received from the transport domain at the RAN entity and the RAN entity may (e.g., indirectly) control the transport node, which then provides Telefonaktiebolaget LM Ericsson (publ) 21 / 62 301-0276WO

[0134] P111758WO01 13 Dec 2024 updated transport-related telemetry information as another (e.g., additional or alternative) embodiment of the receiving step of the first method aspect.

[0135] In this embodiment or in a further embodiment, the transport node may enable connectivity and data transport within a fronthaul network of the RAN by operating entirely at the network layer and / or transport layer without constituting a functional component of the RAN. The transport node may be configured to at least one of: abstract the transport domain (e.g., as a transport infrastructure), facilitate the reliable delivery of packets, and support synchronization without participating in operational processes of the RAN. For example, the transport node may operate on network layer (e.g., OSI L3) headers. Alternatively or in addition, for providing the telemetry information and / or for controlling the transport, a transport layer (e.g., OSI L4) may be used within the transport domain.

[0136] In an embodiment, the transport domain may comprise a packet-based fronthaul of the RAN. Alternatively or in addition, the transport domain may comprise a transport network connecting the RAN entity of the RAN to one or more further RAN entities of the RAN.

[0137] The received telemetry information may relate to components of the transport domain, such as packet-based fronthaul and / or transport network. Accordingly, embodiments can enable the RAN entity to monitor and / or control its fronthaul connections, e.g., connections with other RAN entities of the same RAN. Hence, the telemetry information allows for enhanced monitoring of RAN performance and controlling of the transport domain as a network resource of the RAN, particularly by facilitating precise traffic monitoring and resource allocation based on the telemetry information.

[0138] The inclusion of the transport domain, e.g., as a fronthaul of the RAN and / or as inter-RAN entity connections in telemetry reporting, can enable comprehensive telemetry coverage at the RAN entity. Embodiments can enable RAN entities to make informed decisions and / or change at least one operational parameter, e.g., leading to improved or differentiated service quality and network reliability.

[0139] In an embodiment, the at least one transport node in the transport domain may comprise an edge node, or each edge node, of the transport domain. Telefonaktiebolaget LM Ericsson (publ) 22 / 62 301-0276WO

[0140] P111758WO01 13 Dec 2024

[0141] The transport domain may be a transport network as a physical subset of the RAN. An edge (or boundary) defined by the transport node as an edge node may refer to a point of ingress and / or egress between a RAN-specific transport protocols and RAN-agnostic transport protocols. RAN-specific may mean that the protocol is designed for RAN fronthaul communication.

[0142] By receiving the telemetry information from the one or more edge nodes of the transport domain, embodiments can ensure that the telemetry information is relevant to a point of connection between the RAN entity and the transport network, e.g., enhancing the usefulness and timeliness of the received telemetry information.

[0143] A first examples of a transport protocol that is RAN-specific is a Common Public Radio Interface (CPRI). The CPRI may be specifically designed for RAN traffic (i.e., RAN communication), e.g., to transport digitized radio signals (IQ data) between a baseband unit (BBU) and a remote radio unit (RRU). It may be used for fronthaul links in 4G and early 5G systems. A second examples of a RAN-specific transport protocol is an enhanced Common Public Radio Interface (eCPRI). The eCPRI may be an evolution of CPRI, developed specifically to address the bandwidth and flexibility requirements of 5G RAN. eCPRI may be used in fronthaul communication between distributed units (DUs) and radio units (RUs). A third examples of a RAN-specific transport protocol is an O-RAN Fronthaul Protocol. This RAN-specific protocol may be specified by the Open RAN Alliance to enable inter-vendor and interoperable communication, e.g., in the 5G RAN or later generations. While primarily designed for 5G networks, it supports functional splits (e.g., Option "7.2", i.e. a split between lower-PHY and higher- PHY) between the DU and RU. It is a packet-based transport, supporting Ethernet and IP with RAN-specific features for synchronization and real-time control. A fourth examples of a RAN-specific transport protocol is Radio over Ethernet (RoE). RoE is used for transporting digitized RF signals over Ethernet networks in as the fronthaul. RoE is RAN-specific, as it focuses on encapsulating radio data for transport over Ethernet. A fifth examples of a RAN-specific transport protocol is Open Base Station Architecture Initiative (OBSAI). The OBSAI is a RAN-specific protocol designed for interfacing between the base station components. Telefonaktiebolaget LM Ericsson (publ) 23 / 62 301-0276WO

[0144] P111758WO01 13 Dec 2024

[0145] Examples of a RAN-agnostic transport protocol for the transport domain include Ethernet, Time-Sensitive Networking (TSN), Flexible Ethernet (FlexE), and IP protocols. These protocols may serve broader networking purposes, and may be capable of meeting the stringent requirements of the RAN traffic, such as low latency and time synchronization, e.g., under the RAN entity's transport control based on the telemetry information.

[0146] In an embodiment, the transport node may comprise a telemetry interworking function (TIWF). The transport-related telemetry information may be received from the TIWF of the transport node. Alternatively or in addition, the method further may comprise sending, to the transport node, a configuration message that configures a TIWF at the transport node to collect transport-related telemetry information from the transport domain, and send the collected transport-related telemetry information to the RAN entity.

[0147] An originally collected information from the transport domain may deviate from the transport-related telemetry information (e.g., as sent by the transport node and / or as received by the RAN entity).

[0148] Including a TIWF at the transport node (e.g., an edge node) allows for effective collection and translation of transport telemetry into meaningful parameters for the RAN entity, e.g., facilitating better network management and decisionmaking based on accurate transport performance data.

[0149] The TIWF may be configured for periodically or continuously collecting the transport-related telemetry information. Alternatively or in addition, the telemetry information sent by the TWI (and thus the received telemetry information of the first method aspect) may be processed after information collection and before sending. Alternatively or in addition, the TIWF may be configured to send the telemetry information periodically.

[0150] In an embodiment, the method may further comprise sending, by the RAN entity, a telemetry request to the transport node in the transport domain to request the transport-related telemetry information.

[0151] By enabling the RAN entity to send a telemetry request, method embodiments allow for on-demand (e.g., periodic or even-triggered) retrieval of transport Telefonaktiebolaget LM Ericsson (publ) 24 / 62 301-0276WO

[0152] P111758WO01 13 Dec 2024 performance data, improving the efficiency of RAN operations and / or enabling timely responses to changing conditions in the RAN.

[0153] The RAN entity may send the telemetry request for one or more specific transport paths in the transport domain. For example, the transport path or each of the one or more transport paths may be identified in the telemetry request by a transport path identifier, i.e. a flow label. Alternatively or in addition, the transport-related telemetry information may be specific for one or more flow labels.

[0154] Herein, the expression "flow label" may encompass any identifier of a transport path in the transport domain. The flow label may be a field in a network header (e.g., an IP header) a data packet of the RAN traffic. Alternatively or in addition, the transport path may correspond to one or more segments for segment routing in the transport domain. In a variant of any embodiment, the flow label may be a Flow Label according to IPv6 packet (e.g., according to the IPv6 Flow Label Specification RFC 6437). In another variant of any embodiment, the flow label may be a Differentiated Services Code Point (DSCP).

[0155] Each of the flow labels may be associated with a RAN flow and / or a quality of service (QoS) requirement (e.g., for the associated RAN flow). The RAN entity may use the flow labels to identify corresponding RAN flows and / or any characteristics of RAN traffic, such as needs and / or requirements (e.g., a QoS requirement). The flow label may be any a field in the IP header used to indicate at least one of: RAN flow, priority and handling of data packets of the RAN traffic in the fronthaul of the RAN. Different flow labels may be mapped to different QoS requirements (e.g., different performance requirements) and traffic types (e.g., voice, video, and data).

[0156] Responsive to sending the telemetry request, the RAN entity may receive the transport-related telemetry information. For example, responsive to sending the telemetry request indicative of one or more transport paths (e.g., comprising one or more flow labels), the received transport-related telemetry information may be indicative of a telemetry value for each of the one or more specific transport paths. For example, the received transport-related telemetry information may comprise a telemetry value in association with each of the one or more transport paths. Telefonaktiebolaget LM Ericsson (publ) 25 / 62 301-0276WO

[0157] P111758WO01 13 Dec 2024

[0158] In an embodiment, the telemetry request may be sent by encoding a telemetry indicator in a header field of a data packet sent from the RAN entity to the transport node in the transport domain.

[0159] By encoding the telemetry request in a header field of data packets, such as a, method embodiments can provide an efficient mechanism to request the telemetry information without introducing additional signaling overhead, e.g., optimizing RAN resources and / or simplifying implementation of the method.

[0160] The telemetry indicator in the header field may be indicative of one or more specific transport paths, e.g., by including one or more corresponding transport path identifier, i.e., the flow labels, respectively.

[0161] In a variant of any embodiment, the RAN entity and / or the transport node (e.g., the TIWF) may use flow labels for exchanging flow-specific information, e.g., telemetry requests and / or data packets of RAN traffic. The flow labels may be used (e.g. at the RAN entity and / or the transport node) by including (e.g. appending or modifying) a flow label in the network header of a data packet and / or by reading a flow label from the network header of a data packet. Alternatively or in addition, the flow labels may be used at the RAN entity by mapping a RAN flow of the RAN to a flow label (or vice versa). Alternatively or in addition, the flow labels may be used at the transport node by mapping a flow label to a transport path in the transport domain (or vice versa to flow label).

[0162] In a variant of any embodiment, the transport node or the transport domain may define the one or more flow labels (i.e., path identifiers) relating to certain characteristics of the transport paths identified by the flow labels. For example, the received transport-related telemetry information may comprise the flow labels as defined by the transport node or the transport domain. For example, the RAN entity may initiate the telemetry provisioning by requesting the transport-related telemetry information for a certain number of transport paths. The transport-related telemetry information received in response to the telemetry request may be indicative of the flow labels for the requested number of transport paths. Thus, the RAN entity is provided with the choice to select a transport path using the flow labels (i.e., the transport path identifiers) presented by transport node (e.g., by the TIWF). Telefonaktiebolaget LM Ericsson (publ) 26 / 62 301-0276WO

[0163] P111758WO01 13 Dec 2024

[0164] In a variant of any embodiment, the RAN node may use an IPv6 Flow Label (as a non-limiting example of the flow label). For example, transport node may use the flow label (e.g., a RAN flow information included in, or implied by, the flow label) to select a transport path, e.g. one or more segment identifiers (SID) for segment routing (SR), e.g. a transport path that matches a need or requirement of the RAN flow associated with the flow label. The IPv6 Flow Label may be a 20-bit field in the IPv6 header (i.e., the network layer header).

[0165] Preferably, the RAN entity is agnostic as to the SR and / or the one or more SID defining the transport path. A mapping, by the RAN entity, between the flow label (indicating a transport path) and the RAN flow may be exclusively based on the received transport-related telemetry information. The SID may be a 128-bit IPv6 address, or a smaller compressed SID (CSID), that represents a specific instruction segment of function in the fronthaul of the RAN. Only within the transport domain, the SID may be encoded in data packets of the RAN traffic in a destination address or as part of a segment routing header (SRH).

[0166] In an embodiment, the transport-related telemetry information may include a packet loss rate associated with the transport domain. Alternatively or in addition, the transport-related telemetry information may include a packet latency associated with the transport domain. Alternatively or in addition, the transport-related telemetry information may include a jitter associated with the transport domain.

[0167] By receiving one or each of these specific types of telemetry information, method embodiments can ensure that the RAN entity obtains critical performance metrics necessary for maintaining service quality and implementing effective network management strategies. For example, different types of telemetry information (or different numerical and / or logical combinations of types of telemetry information) may trigger different changes in a configuration of the transport domain, e.g. as to gating and routing.

[0168] In an embodiment, the method may further comprise changing, based on the received transport-related telemetry information, at least one operational parameter of the RAN entity and / or the transport node. Telefonaktiebolaget LM Ericsson (publ) 27 / 62 301-0276WO

[0169] P111758WO01 13 Dec 2024

[0170] By utilizing the telemetry information to control at least one operational parameter, such as traffic generation rates, resource allocations, and traffic steering, the RAN entity can (e.g., preemptively) control network performance, improving service quality, and optimizing network efficiency.

[0171] From the perspective of the RAN entity (i.e., for the steps of the first method aspect), changing the at least one operational parameter of the RAN entity may be referred to as a direct control. Changing the at least one operational parameter of the transport node may also be referred to as an indirect control. Consequently, the "change" of the at least one operational parameter may relate to the direct control and / or the indirect control.

[0172] In an embodiment, the changing of the at least one operational parameter of the transport node may comprise sending, based on the received transport-related telemetry information, a control message to the transport node. The control message may trigger a change of at least one operational parameter of the transport node.

[0173] Sending the control message to the transport node may be an example of the changing of the at least one operational parameter of the transport node, i.e. the indirect control. Consequently, the reference sign 308 for the (e.g., indirectly) changing step, as performed by the RAN entity, may also be used for the corresponding sending step performed by the RAN entity. Furthermore, the direct control (i.e., change) performed at the transport node (e.g., triggered by the control message) is referred to by the reference sign 408.

[0174] In an embodiment, the change of the at least one operational parameter may comprise selecting, based on the received transport-related telemetry information, a different transport path in the transport domain for RAN traffic. Alternatively or in addition, the change of the at least one operational parameter may comprise reallocating, based on the received transport-related telemetry information, RAN traffic to alternative transport paths outside of the transport domain of the transport node.

[0175] Herein, the RAN traffic may encompass data packets sent from and / or received at the RAN entity. Telefonaktiebolaget LM Ericsson (publ) 28 / 62 301-0276WO

[0176] P111758WO01 13 Dec 2024

[0177] By selecting an alternative transport path based on telemetry information being indicative of an issue with a current path, the RAN entity can avoid network congestion or failures (e.g., preemptively), enhancing data transmission performance and reliability.

[0178] The changing of the at least one operational parameter may comprise selecting a different transport path in the transport domain for RAN traffic if the packet loss rate associated with the transport domain fails to fulfill a predefined criterion, e.g., exceeds a predetermined threshold. Alternatively or in addition, the changing of the at least one operational parameter may comprise reducing a traffic generation rate of the RAN entity if the packet loss rate or the packet latency or jitter associated with the transport domain fails to fulfill a predefined criterion, optionally exceeds a predefined threshold.

[0179] Herein, "predefined" may encompass configured (e.g., by a core network function) and / or specified (e.g., by a 3GPP technical specification) and / or predetermined by an earlier control message and / or hard-coded at the RAN entity.

[0180] The RAN entity may change (e.g., initiate the change of) the one or more operational parameters based on different values and / or different types of received telemetry information. For example, if the packet loss rate is too high, the RAN entity may select a different transport path to ensure reliable transport of the RAN traffic in the transport domain. Alternatively or in addition, if latency and / or jitter are higher than acceptable levels, the RAN entity may adjust its traffic generation rate for RAN traffic to mitigate the impact on service quality. Depending on whether the not-fu If il led criterion is based on packet loss, latency, or jitter, the RAN entity reallocates traffic accordingly.

[0181] In an embodiment, the RAN entity may be a digital unit (DU) or a centralized unit (CU) of the RAN.

[0182] A plurality of DUs may be connected over one or more embodiments of the transport domain to a CU, e.g., for the RAN providing distributed multiple-input multiple-output (distributed MIMO) radio access.

[0183] In an embodiment, the transport domain may comprise a transport tunnel. Telefonaktiebolaget LM Ericsson (publ) 29 / 62 301-0276WO

[0184] P111758WO01 13 Dec 2024

[0185] The transport domain, e.g., the transport tunnel, may include alternative paths (e.g., connecting the same pair of end points). Controlling the transport performed by the transport node (e.g., changing the at least one operational parameter at the transport node) may comprise controlling the selection of the alternative paths.

[0186] In an embodiment, the transport node may be a tunnel endpoint (TEP) node of the transport tunnel and / or. The transport tunnel comprises a plurality of routing segments and the transport node may be a router connecting at least two of the routing segments.

[0187] The TEP may be a gateway or router.

[0188] The routing segments may be examples of the different (e.g., alternative) transport paths in the transport domain. For example, each transport path may be defined by (e.g., a sequence of) one or more routing segments.

[0189] An operation of the transport node as a router may comprise performing routing, e.g., segment routing.

[0190] In an embodiment, the transport domain may comprise one or more segments for segment routing (SR). Alternatively or in addition, the transport node may be configured to perform segment routing (SR) in the transport domain.

[0191] In an embodiment, the segment routing (SR) may use SR over internet protocol version 6, SRv6, or SR over multi-protocol label switching, SR-MPLS.

[0192] The transport domain may use SRv6 tunneling or SR-MPLS tunneling, e.g., performed or controlled by the transport node. Embodiments of the method can address challenges of making transport-related telemetry information available in packet-based fronthaul networks that require traffic engineering capabilities, e.g., enabling the RAN entity to monitor and / or control transport in the transport domain using tunneling. Telefonaktiebolaget LM Ericsson (publ) 30 / 62 301-0276WO

[0193] P111758WO01 13 Dec 2024

[0194] Controlling the transport in the transport domain may comprise controlling the segment routing. Alternatively or in addition, the changed at least one operational parameter of the transport node may relate to the segment routing.

[0195] In an embodiment, the method may further comprise controlling the SR performed by the transport node for data packets of the RAN entity using flow labels included in the data packets based on the received transport-related telemetry information.

[0196] The RAN entity may include (e.g., add or modify) flow labels in the data packets. Using the flow labels to label the data packets, the RAN entity may differentiate the data packets and / or map different RAN flows of the RAN to different flow labels of the transport domain.

[0197] The controlling of the SR by sending data packets that include flow labels may be an example of the indirect control.

[0198] In an embodiment, the received transport-related telemetry information may comprise different values associated with different flow labels in a network layer header of data packets for the RAN entity.

[0199] The received transport-related telemetry information may be flow-specific.

[0200] In an embodiment, the RAN entity may include flow labels in network layer headers of data packets. A mapping between RAN flows of the RAN and the flow labels included in the network layer headers may be dependent on the received transport-related telemetry information. Alternatively or in addition, a mapping between the flow labels included in the network layer headers and transport paths of the transport domain may be dependent on the received transport- related telemetry information.

[0201] Herein, the RAN entity including the flow labels may be a step of the first method aspect. The step may encompass appending a network layer header that is indicative of the flow label or modifying a network layer header to include or change the flow label for one or more data packets. Telefonaktiebolaget LM Ericsson (publ) 31 / 62 301-0276WO

[0202] P111758WO01 13 Dec 2024

[0203] The data packets including the flow labels may be sent from the RAN entity to the transport node and / or for transport in the transport domain. The network layer header may be an IPv4 or IPv6 header and / or a header added to the data packet at a network layer of the RAN entity.

[0204] The transport path may be defined by segment routing (SR). For example, one or more segment identifiers (SID) may define the transport path. The transport node may include the one or more SID in a segment routing header (SRH) of an IPv6 packet according to the mapping between the flow labels included in the network layer headers and the transport paths of the transport domain.

[0205] The mapping between RAN flows of the RAN and the flow labels of the headers at the RAN entity may be an example of the at least one operational parameter of the RAN entity. Changing the at least one operation parameter at the RAN entity may comprise changing the mapping between RAN flows of the RAN and the flow labels in the (e.g., network layer) headers of data packets.

[0206] Alternatively or in addition, the mapping between the flow labels included in the network layer headers and the transport paths may be an example of the at least one operational parameter of the transport node. Changing the at least one operation parameter at the transport node may comprise changing the mapping between a flow label in (e.g., network layer) headers of data packets and a transport path (e.g., defined by one or more SID).

[0207] Including (e.g., adding or modifying) the flow label in a data packet may be an example of the RAN entity controlling the transport of the data packet. The controlling of the transport within transport domain by the RAN entity may be an indirect control using the flow labels. By mapping the RAN flows to flow labels, and / or by mapping the flow labels to one or more segment identifiers (SID) used in the segment routing to steer RAN traffic over selected (i.e., alternative) transport paths in the transport domain, the RAN entity may indirectly control the transport based on the received transport-related telemetry information.

[0208] For example, the RAN entity may (e.g., indirectly) control the segment routing (SR) performed by the transport node by indirectly modifying the one or more SID defining a transport path of a data packet by including a flow label in the data packet based on the received transport-related telemetry information. This may Telefonaktiebolaget LM Ericsson (publ) 32 / 62 301-0276WO

[0209] P111758WO01 13 Dec 2024 be an indirect control. The RAN entity may change the flow label, what causes a different TE path (described by different SIDs) within the transport domain by the edge router. RAN nodes are not aware that SR is used within the transport domain.

[0210] As a result, the RAN entity may steer RAN traffic in the transport domain based on the received transport-related telemetry information, e.g., without being aware of a physical transport path or the SR used within the transport domain. Alternatively or in addition, the RAN entity may control RAN traffic being routed in the transport domain over one or more transport paths associated with a performance fulfilling a quality of service (QoS) requirement of the RAN flow. The received transport-related telemetry information may be indicative of one or more performance values associated with one or more transport paths, respectively, e.g., by indicating one or more values of the transport-related telemetry that are specific for one or more flow labels, respectively.

[0211] Herein, any transport path may be referred to as traffic engineering (TE) path, e.g., to express that the transport path is controlled by one or more SID.

[0212] In an embodiment, the method may further comprise partitioning RAN traffic into multiple traffic classes based on criteria, optionally the criteria depending on at least one of a quality of service (QoS) requirement, a type of traffic, a connection type, and service characteristics of the RAN traffic. Alternatively or in addition, the method may further comprise controlling the transport node to route the RAN traffic of each of the traffic classes over transport paths in the transport domain selected based on the transport-related telemetry information received for each of the transport paths fulfilling the criteria of the respective traffic classes.

[0213] The multiple traffic classes may correspond to different RAN flows of the RAN.

[0214] The transport domain (e.g., the transport tunnel) may comprise a plurality of alternative transport paths. Each of the alternative transport paths may be associated with different telemetry values in the transport-related telemetry information. Telefonaktiebolaget LM Ericsson (publ) 33 / 62 301-0276WO

[0215] P111758WO01 13 Dec 2024

[0216] The controlling of the transport node to route the RAN traffic may comprise controlling the SR performed by the transport node for data packets of the RAN traffic according to flow labels included in the data packets (e.g., included by and / or at the RAN entity) based on the received transport-related telemetry information. Including (e.g., adding or modifying) the flow labels in the data packets of the RAN may also be referred to as labeling the RAN traffic.

[0217] The RAN entity may partition and / or control the (e.g., segment) routing of the RAN traffic based on various factors, e.g., a Quality of Service (QoS) requirement.

[0218] For example, high-priority or latency-sensitive RAN traffic (e.g., a voice call) may be labeled for routing over paths with less latency and / or less packet loss. An alternative or additional factor for the partitioning and / or the controlling may comprise a type of the RAN traffic. Different types of RAN traffic (e.g., associated with different applications or services such as streaming video, web browsing) may be associated with different QoS requirements. An alternative or additional factor for the partitioning and / or the controlling may comprise a connection type. For example, default bearers and dedicated bearers of the RAN may be treated differently. An alternative or additional factor may comprise service characteristics. For example, RAN traffic with a guaranteed bit rate (GBR) may be given priority over non-GBR traffic.

[0219] By partitioning the RAN traffic based on at least one of these factors and using the received transport-related telemetry information to select the matching flow label (e.g., and thus a matching transport service in the transport domain, the RAN entity may control RAN performance (e.g., to maintain a service level agreement, SLAs) including controlling the transport in the fronthaul of the RAN.

[0220] The RAN entity may label (i.e., mark) the data packets of the RAN traffic according to the received transport-related telemetry information. Routing the labelled data packets may be the (e.g., exclusive) task of the transport node (e.g., as a router) or any other transport domain nodes (e.g., as routers). Preferably, the RAN entity only provides information on required service over the transport domain by setting the flow label (e.g. in a field of the data packet of the RAN traffic), while routing (e.g. selecting the most proper or best suited transport path) is a task for the transport node as the router. Telefonaktiebolaget LM Ericsson (publ) 34 / 62 301-0276WO

[0221] P111758WO01 13 Dec 2024

[0222] According to a second method aspect, a method is performed by a transport node in a transport domain of a radio access network (RAN). The method comprises sending, to at least one RAN entity of the RAN, transport-related telemetry information indicative of telemetry of the transport domain.

[0223] In an embodiment, the sending of the transport-related telemetry information may comprise sending, optionally multicasting, the transport-related telemetry information to a plurality of RAN entities in the RAN.

[0224] In an embodiment, the transport node may comprise a telemetry interworking function (TIWF). The method may further comprise collecting, by the TIWF, transport-related telemetry information from the transport domain, optionally responsive to receiving a configuration message from the at least one RAN entity. Alternatively or in addition, the transport node may comprise a telemetry interworking function (TIWF) and the method may further comprise sending, by the TIWF, the collected transport-related telemetry information to the at least one RAN entity.

[0225] In an embodiment, the method may further comprise receiving, from the at least one RAN entity, a telemetry request requesting the transport-related telemetry information. Alternatively or in addition, the method may further comprise responsive to the telemetry request, collecting the transport-related telemetry information from the transport domain.

[0226] In an embodiment, the transport node may collect the transport-related telemetry information by measuring transport-specific telemetry data within the transport domain. The method may further comprise translating, by the TIWF, the transport-specific telemetry data into RAN-specific telemetry parameters to be sent as the transport-related telemetry information to the at least one RAN entity.

[0227] In an embodiment, the transport node may collect the transport-related telemetry information for a bidirectional path comprising a pair of reversely configured unidirectional transport tunnels in the transport domain. Telefonaktiebolaget LM Ericsson (publ) 35 / 62 301-0276WO

[0228] P111758WO01 13 Dec 2024

[0229] Fig. 6 shows an example of a fronthaul (FH) in the RAN 500 and a telemetry domain therein, i.e., a transport domain 550 for which telemetry data can be collected by transport nodes 200 in the transport domain 550.

[0230] The depiction of the network link between R1 and R3 in Fig. 6 as connected by a single tunnel indicates a simplified representation of the transport tunnel for telemetry purposes. In Fig. 5, the presence of an additional router R5 may refer to a different scenario or may further specify the scenario of Fig. 6. For example, the transport tunnel may extend beyond the router R5, while the Fig. 6 emphasizes the telemetry function between the endpoints R1 and R3. That is, Fig. 6 is meant to highlight the telemetry measurement rather than the detailed routing path. The transport telemetry may extend beyond a single router (like R5 in Figs. 5 and 6). The TIWF 201 may monitor (e.g., collect) and report on the entire path of the tunnel, optionally covering multiple network segments and routers, depending on how the telemetry is configured and implemented.

[0231] In both Fig. 5 and Fig. 6, at least some of the routers R act as Tunnel Endpoints (TEPs) for the transport domain 550. In any embodiment, at least one of the TEPs may handle the transport-related telemetry information 600, e.g., obtain (i.e., collect 402) the telemetry information 600 for the transport domain 550 and provide (i.e., sent 406) it within the RAN 500 beyond the transport domain 550.

[0232] The transport tunnel may be implemented according to the technical standard document RFC 8986 on "Segment Routing over IPv6 (SRv6) Network Programming", e.g., for configuring the TEPs and / or Segment Identifiers (SID) for SRv6 (SRv6 SID). The RFC 8986 standard does not always require routers specifically at the TEPs. Instead, the standard describes the use of SRv6-capable nodes to instantiate SID, which nodes may comprise routers or other network devices. E.g., as illustrated in Figs. 5 and 6 in combination, a router (e.g., transport node 200) may exist within the transport tunnel. The concept of segment routing inherently allows for routers (e.g., transport node 200) to be intermediate points in the path defined by SIDs.

[0233] In terms of the open systems interconnection (OSI) model, the transport node 200 (e.g., the router) may operate at the network layer (layer 3), e.g., handling IP addresses and routing data packets of the RAN traffic between different networks (e.g., between RAN entities 100 and transport nodes 200). Transport tunnels, Telefonaktiebolaget LM Ericsson (publ) 36 / 62 301-0276WO

[0234] P111758WO01 13 Dec 2024 particularly those using SRv6, may operate at the network layer, as they involve encapsulating data packets of the RAN traffic within IPv6 packets using IPv6 headers that are routed through the transport domain 550 of the FH of the RAN 500.

[0235] Herein, the technical meaning of a "segment" may be associated with the transport in the transport domain 550, e.g., with the routing. A segment may refer to a transport path (e.g., a routing path) or a part of a transport path. The transport or routing may be implemented by Segment Routing (SR) over IPv6 (SRv6), wherein the segment is defined by a Segment Identifier (SID). Each segment may represent a specific instruction or routing behavior in the FH network. Multiple SIDs may be included in the segment routing header (SRH) of an IPv6 packet. The standard document RFC 8986 on "SRv6 Network Programming" defines segments in the context of SRv6, wherein a segment is a part of a routing path identified by an SID. Moreover, "tunnel" may refer to an encapsulation. A data packet may be transported across the FH of the RAN 500 in such a way that a transport path is abstracted from its endpoints. In the context of the FH of the RAN 500, the transport domain 550 (e.g., transport tunnels) may be used for the transport of data packets between RAN entities 100.

[0236] Embodiments of the technique make transport-related telemetry information 600 available to RAN entities 100. In existing fronthaul (FH) networks, transport tunnel- related telemetry information is terminated at tunnel endpoints (TEPs) within the transport domain 550. Therefore, transport-specific telemetry is conventionally not available for nodes outside of the transport domain 550, particularly not available for RAN entities 100.

[0237] For example, at least one transport domain node (i.e., transport node 200) in the RAN 500 may comprise a telemetry interworking function (TIWF) 201 that is configured to make transport-related telemetry information 600 available in the RAN 500. The at least one transport domain node 200 may be an entity of a transport network (i.e., the transport domain 550) of the RAN. For example, the at least one transport domain node 200 may be a node arranged at an edge (e.g., ingress or egress) of a transport domain 550, e.g., a transport tunnel. The transport domain node 200 may be a tunnel endpoint (TEP) node. The TEP node may be arranged and / or configured to terminate a transport tunnel. Alternatively or in addition, the at least one transport domain node 200 may function on a transport Telefonaktiebolaget LM Ericsson (publ) 37 / 62 301-0276WO

[0238] P111758WO01 13 Dec 2024 layer of a fronthaul of the RAN and / or may be transparent to RAN entities 100 of the RAN and / or may be no functional component of the RAN.

[0239] The transport-related telemetry information 600 may be indicative of telemetry of the transport domain 550, e.g. telemetry of the transport tunnel. The operation of the TIWF 201, i.e., the method 400, may comprise providing (i.e., sending 406) the transport-related telemetry information 600 (optionally after processing) to the RAN entities 100. The TIWF 201 collects 402 the transport tunnel specific telemetry information 600, optionally translates it to meaningful RAN telemetry parameters, and sends 406 it to (e.g., selected) RAN entities 100.

[0240] The second aspect may comprise a Telemetry Interworking Function (TIWF) 201 as a device aspect located at transport tunnel endpoints (e.g., as a non-limiting example of the transport node 200. Alternatively or in addition, the second aspect may comprise a method aspect 400 for the operation of the TIWF 201.

[0241] Any embodiment of any aspect may comprise at least one of the following features and steps described in more detail below. While the description may use the perspective of the second aspect (i.e., the method 400 at the transport node 200), such description readily informs the skilled person as to corresponding features and steps of the first aspect (i.e., for the method 300 at the RAN entity).

[0242] The Telemetry Interworking Functionality (TIWF) 201 is located on a transport "edge Node" as an example of the transport node 200. The TIWF 201 (i.e., the method 400) may comprise collecting 402 a transport-related telemetry information 600 (e.g., tunnel-specific telemetry information (e.g., continuously or on-demand). The transport-related telemetry information 600 may be indicative of packet loss and / or packet latency.

[0243] As an optional substep of the step 402, the method 400 may comprise translating the transport-related telemetry information 600 (e.g., tunnel telemetry information) to meaningful or reduced RAN telemetry parameters.

[0244] In an alternative or additional substep of the step 402, the method 400 may comprise generating (e.g., extra or dedicated) telemetry packets (e.g., indicated at reference sign 602 in Fig. 7) for nodes, e.g., the RAN entity 100, outside of the Telefonaktiebolaget LM Ericsson (publ) 38 / 62 301-0276WO

[0245] P111758WO01 13 Dec 2024 transport domain 550, e.g., RAN endpoints like a DU or RU, and / or a telemetry information collector module.

[0246] Any one of the steps (or substeps) of the method 400, e.g., the collecting 402 and / or the sending 406, may be trigged by a trigger-event. Examples for the trigger-event (e.g., for generating transport-external telemetry packets, i.e., telemetry information packet 602, may be based on at least one of the following trigger-event examples.

[0247] A first trigger-event example is an explicit telemetry request (i.e., the reception according to the step 404 of the method 400). The request may be encoded in the external flow (e.g., in the FlowLabel of a RAN IPv6 data packet).

[0248] A second trigger-event example is a telemetry timer that expires. The timer may be located and / or may expire at the transport node 200 (e.g., a transport edge node of the transport domain 550).

[0249] A third trigger-event example comprises a dedicated telemetry packet received from the external domain (e.g., generated by the RAN entity 100).

[0250] A fourth trigger-event may be based on a publish and / or subscribe approach. This trigger-event activates when specific conditions or changes are detected in the network, and these conditions align with a subscription set by an external entity, e.g. the RAN entity 100. The telemetry information is then sent 406 (e.g., published) to the subscriber 100 in near real-time or on a defined schedule.

[0251] The transport node 200 acts as publisher, e.g., network devices or systems (e.g., routers, switches, monitoring systems) act as publishers. The RAN entity 100 acts a subscriber. Optionally, a broker can mediate communication between publishers 200 and subscribers 100, e.g., enhancing scalability of the telemetry provisioning.

[0252] For example, in the step 302, the RAN entity 100 subscribes to the TWIF 201, wherein the configuration message informs the TWIF 201 about a QoS requirement (e.g., for SLA compliance). The TWIF 201, as part of the step 402, monitors the QoS requirement and sends 406 the telemetry information 602 when it is in a predefined margin from violating the QoS requirement. Telefonaktiebolaget LM Ericsson (publ) 39 / 62 301-0276WO

[0253] P111758WO01 13 Dec 2024

[0254] Fig. 7 , at its horizontal center, schematically illustrates a transport node 200 comprising a TIWF 201 at the edge of a transport domain 550, being a transport tunnel in the illustrated example.

[0255] A telemetry information request, which is sent in the step 304 and received in the step 404, from a transport-external domain such as the RAN entity 100, may be specified in a modification of the standard documents mentioned herein. Alternatively or in addition, encoding of such a telemetry-request may be implemented in the IP header of "RAN data packets", e.g., data packets of the RAN traffic. For example, in case of IP RAN communication the "FlowLabel" of IPv6 may be used to contain RAN flow-specific information. This information may include one or more telemetry bits (T-bits) to inform the transport domain 550, i.e., the transport node 200 and its TIWF 201, that the RAN (e.g., the RAN entity 100) is interested in receiving the telemetry information 602 for the indicated RAN flow. Multiple formats of such a T-bits are possible:

[0256] • Single T-bit format may be indicative of telemetry being on or off.

[0257] • Multiple T-bits may specify what telemetry information 602 is requested.

[0258] Transport domain-edge node (e.g., transport node 200) actions are as follow:

[0259] • Telemetry Interworking Function detects the T-bits of the data packet.

[0260] • Executes telemetry measurement inside the transport domain (550, e.g., SRv6 domain) on the tunnel, which is selected by the data packet (if results not already exist, e.g., due to continuous periodic telemetry measurement).

[0261] • Generates telemetry information packet 602 and sends 406 it to a domain external entity, i.e., the RAN entity 100 (e.g., a DU).

[0262] Fig. 7 schematically illustrates an operation of the TIWF 201, including the sending 406 of the telemetry information 602.

[0263] Telemetry information 600 may be received (in the step 306) and transmitted (in the step 406) in a telemetry information packet 602. Telefonaktiebolaget LM Ericsson (publ) 40 / 62 301-0276WO

[0264] P111758WO01 13 Dec 2024

[0265] In a variant of any embodiment of either aspect, the telemetry information packet 602 has at least one of the following characteristics. First, it is generated by the telemetry interworking function (TIWF) 201. Second, it contains as ID-information the source IP address (srclP), the destination IP address (dstIP), and / or the FlowLabel of the trigger packet (e.g., the configuration message or the subscription). The telemetry information 600 may allow the RAN entity 100 to identify (i.e., map) to which RAN flow the telemetry information refers). Third, the packet 602 comprises the telemetry data (i.e., the transport-related telemetry information 600, optionally processed), for example packet loss and / or latency of the transport path that is used by the specified RAN flow of the RAN 500.

[0266] A packet format for reporting the transport-related telemetry information 600 may use or modify a standardized communication protocol. A first example of the telemetry information packet 602 is an 0AM packet format for Operations, Administration, and Maintenance (0AM) as defined by the International Telecommunication Union - Telecommunication Standardization Sector (ITU-T). A second example of the telemetry information packet 602 is a Performance Measurement (PM, also: Performance Monitoring) packet as defined by Internet Engineering Task Force (IETF).

[0267] It is noted that the transport domain 550 (e.g., transport tunnels) may be, by definition, unidirectional. The telemetry data collection 402 and sharing 406 with transport external entities 100 may be triggered by an ingress packet, so telemetry information 600 refers to the tunnel from ingress to egress.

[0268] A request for telemetry on a bidirectional transport path may be served via additional configuration, i.e., the telemetry interworking functions (TIWF) 201 at the ingress and / or the egress edge nodes 200, e.g. as illustrated on the left-hand and right-hand end of the tunnel 550 in Fig. 7, may be configured with an uplinkdownlink tunnel pairing information. Such information may be necessary for the measurement entities / agents (e.g., TIWF 201) as well (e.g., Session-sender, Session-Reflector in STAMP (Simple Two-Way Active Measurement Protocol) terminology). In such a case the TIWF 201 collects 402 telemetry information 600 for the paired tunnels and provides them to the RAN 500.

[0269] Any embodiment may further comprise features of the following example of using the TIWF 201 to provide packet loss (as telemetry information 600) that happened Telefonaktiebolaget LM Ericsson (publ) 41 / 62 301-0276WO P111758WO01 13 Dec 2024 within the transport domain 550. This example shows how to provide packet loss information 600 to RAN entities 100 via a combination of (1) STAMP, (2) SRv6 Counters, and the (3) TIWF 201.

[0270] STAMP extensions contain a Direct Measurement TLV in RFC 8972 (Section 4.5), which enables the collection of the number of in-profile packets:

[0271] • Session-Sender Tx counter (S_TxC): number of the transmitted in-profile packets

[0272] • Session-Reflector Rx counter (R_RxC): value of the received in-profile packets

[0273] • Session-Reflector Tx counter (R_TxC): value of the transmitted in-profile packets

[0274] Any one of these counters may be used to detect packet loss and / or provide information about the severity of loss. The specification document RFC 8972 does not define the in-profile criteria for these counters.

[0275] Usage of SRv6 as tunneling can easily provide the missing in-profile definition as RFC 8986 requires the implementation of counters that are specific for SID (Segment Identifier), optionally using Compressed SID (CSID), e.g. according to above-mentioned CSID draft. As the transport paths (i.e., the traffic steering paths) are defined by the SIDs, these SIDs can be used as the "in-profile" criteria in IP Fronthaul scenarios. At the same time, an egress SID represents the TEP 200 at the egress transport node.

[0276] RFC 8986 - Segment Routing over IPv6 (SRv6) Network Programming - states in Section 6 on "Counters":

[0277] "A node supporting this document SHOULD implement a pair of traffic counters (one for packets and one for bytes) per local SID entry, for traffic that matched that SID and was processed successfully (i.e., packets that generate ICMP Error Messages or are dropped are not counted). The retrieval of these counters from MIB, NETCONF / YANG, or any other data structure is outside the scope of this document. " Telefonaktiebolaget LM Ericsson (publ) 42 / 62 301-0276WO

[0278] P111758WO01 13 Dec 2024

[0279] The TIWF 201 on the ingress transport node (as an example of the transport node 200) has a STAMP session with the egress edge node 200. In the SRv6 transport domain 550, a dedicated SID per transport path can provide the required counter for each path, so the TIWF 201 collects 402 telemetry information 600 for each path. The TIWF 201 provides 406 the measurement results to the RAN entities 100 when sharing of telemetry information 602 is triggered.

[0280] Any embodiment disclosed herein may be a cloud implementation, i.e., deployment, configuration, and / or integration of the TWIF 201 may use remote computing resources, services, and / or infrastructure via internet-based protocols. Alternatively or in addition, the RAN entity 100 may be implemented in the cloud. If doing so, the related functions (i.e., the method 300) are by nature implemented together with the RAN entities 100.

[0281] Alternatively or in addition, any embodiment disclosed herein may be an O-RAN Implementation. The methods 300 and 400 may work in the fronthaul as a part of an O-RAN scenario. In the O-RAN context, measurements may be requested by the O-DU (e.g., an O-RAN distributed unit that may be equivalent to a baseband node) or an O-RU controller (e.g., a network function that is permitted to control the configuration of an O-RU), each of which is an example of the RAN entity 100. Examples of O-RU controllers include, an O-DU, a classical NMS, an O-RAN Service Management and Orchestration function, or other network automation platforms.

[0282] Alternatively or in addition, any embodiment of the RAN entity 100 disclosed herein may be implemented on RAN nodes according to a specific generation of radio access technology (RAT), such as a 4G eNB, a 5G gNB or a 6G xNB.

[0283] Fig. 8 shows a RAN entity 100 (e.g., a network node of the RAN 500) in accordance with some embodiments. As used herein, RAN entity refers to equipment capable, configured, arranged and / or operable to communicate directly or indirectly with a radio device (e.g., UE) and / or with other RAN entities or equipment, in a telecommunications network, e.g., with a transport node 200. In accordance with respective embodiments, RAN entity 100 may be configured to operate in a fronthaul of a RAN of a communication system, e.g., as schematically illustrated in Figs. 5, 6 and 7. Examples of RAN entity include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR gNodeBs Telefonaktiebolaget LM Ericsson (publ) 43 / 62 301-0276WO

[0284] P111758WO01 13 Dec 2024

[0285] (gNBs)), O-RAN nodes or components of an O-RAN node (e.g., O-RU, O-DU, optionally O-CU).

[0286] The RAN entity may comprise the functionality as described herein below, or a functional part thereof.

[0287] RAN entities 100 may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. RAN entity 100 may be a relay node or a relay donor node controlling a relay. RAN entities 100 may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g., in an O-RAN access node) and / or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

[0288] Other examples of RAN entities 100 include multiple transmission point (multi- TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell / multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, SelfOrganizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and / or Minimization of Drive Tests (MDTs).

[0289] In particular embodiments, RAN entity 100 includes a processing circuitry 802, a memory 804, a communication interface 806, and a power source 808. In general, in a particular embodiment of RAN entity 100, processing circuitry 802, memory 804, communication interface 806, and power source 808 may, in whole or in part, represent or include physical components common to or shared by one or more of the other elements of RAN entity 100.

[0290] The RAN entity 100 may be composed of multiple distinct network entities (e.g., a NodeB entity and a RNC entity, or a BTS entity and a BSC entity, etc.), which may each have or utilize their own respective physical components. In certain Telefonaktiebolaget LM Ericsson (publ) 44 / 62 301-0276WO

[0291] P111758WO01 13 Dec 2024 scenarios in which the RAN entity 100 comprises multiple such entities (e.g., BTS and BSC), one or more of the separate entities may be shared among several RAN entities. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate RAN entity. In some embodiments, the RAN entity 100 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memories 804 or portions of memory 804 for different RATs) and some components may be reused (e.g., a same antenna 810 may be shared by different RATs). The RAN entity 100 may also include multiple sets of the various illustrated components for different wireless technologies integrated into RAN entity 100, for example GSM, WCDMA, LTE, NR, Wi-Fi (e.g., according to an IEEE 802.11 family standard), ZigBee, Z-Wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within RAN entity 100.

[0292] The processing circuitry 802 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and / or encoded logic operable to provide, either alone or in conjunction with other components, such as the memory 804, to provide RAN entity 100 functionality.

[0293] In some embodiments, the processing circuitry 802 includes a system on a chip (SOC). In some embodiments, the processing circuitry 802 includes one or more of radio frequency (RF) transceiver circuitry 812 and baseband processing circuitry 814. In some embodiments, the RF transceiver circuitry 812 and the baseband processing circuitry 814 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 812 and baseband processing circuitry 814 may be on the same chip or set of chips, boards, or units.

[0294] The memory 804 may comprise any form of volatile or non-volatile computer- readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random Telefonaktiebolaget LM Ericsson (publ) 45 / 62 301-0276WO

[0295] P111758WO01 13 Dec 2024 access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device-readable and / or computer-executable memory devices that store information, data, and / or instructions that may be used by the processing circuitry 802. The memory 804 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions capable of being executed by the processing circuitry 802 and utilized by the RAN entity 100. The memory 804 may be used to store any calculations made by the processing circuitry 802 and / or any data received via the communication interface 806. In some embodiments, the processing circuitry 802 and memory 804 is integrated.

[0296] The communication interface 806 is used in wired or wireless communication of signaling and / or data with UEs, other RAN entities, and / or any other network equipment. In the illustrated embodiment, communication interface 806 comprises ports 816 (e.g., terminals) to send and receive data, for example to and from a network over a wired connection. In particular embodiments, the RAN entity 100 may be capable of wireless communication and communication interface 806 may also include radio front-end circuitry 818 that may be coupled to, or in certain embodiments a part of, an antenna 810. Particular embodiments of radio front-end circuitry 818 include one or more filters 820 and one or more amplifiers 822. The radio front-end circuitry 818 may be connected to an antenna 810 and processing circuitry 802. The radio front-end circuitry may be configured to condition signals communicated between antenna 810 and processing circuitry 802. The radio front-end circuitry 818 may receive digital data that is to be sent out to other RAN entities or UEs via a wireless connection. The radio front-end circuitry 818 may convert the digital data into a radio signal(s) having the appropriate channel and bandwidth parameters using a combination of filters 820 and / or amplifiers 822. The radio signal(s) may then be transmitted via the antenna 810. Similarly, when receiving data, the antenna 810 may collect radio signals which are then converted into digital data by the radio front-end circuitry 818. The digital data may be passed to the processing circuitry 802. In other embodiments, the communication interface may comprise different components and / or different combinations of components. Telefonaktiebolaget LM Ericsson (publ) 46 / 62 301-0276WO

[0297] P111758WO01 13 Dec 2024

[0298] In certain alternative embodiments, RAN entity 100 may be capable of wireless communication but does not include separate radio front-end circuitry 818, instead, the processing circuitry 802 includes radio front-end circuitry and is connected to the antenna 810. Similarly, in some embodiments, all or some of the RF transceiver circuitry 812 is part of the communication interface 806. In still other embodiments, the communication interface 806 includes one or more ports or terminals 816, the radio front-end circuitry 818, and the RF transceiver circuitry 812, as part of a radio unit (not shown), and the communication interface 806 communicates with the baseband processing circuitry 814, which is part of a digital unit (not shown).

[0299] The antenna 810 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 810 may be coupled to the radio front-end circuitry 818 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 810 is separate from the RAN entity 100 and connectable to the RAN entity 100 through one or more interfaces or ports.

[0300] The antenna 810, communication interface 806, and / or the processing circuitry 802 may be configured to perform some or all of the receiving operations and / or obtaining operations described herein as being performed by the RAN entity 100. Any information, data and / or signals may be received from a UE, another RAN entity and / or any other network equipment. Similarly, the antenna 810, the communication interface 806, and / or the processing circuitry 802 may be configured to perform some or all of the transmitting or sending operations described herein as being performed by the RAN entity 100. Any information, data and / or signals may be transmitted to a UE, another RAN entity and / or any other network equipment.

[0301] The power source 808 provides power to the various components of RAN entity 100 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 808 may further comprise, or be coupled to, power management circuitry to supply the components of the RAN entity 100 with power for performing the functionality described herein. For example, the RAN entity 100 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power Telefonaktiebolaget LM Ericsson (publ) 47 / 62 301-0276WO

[0302] P111758WO01 13 Dec 2024 source supplies power to power circuitry of the power source 808. As a further example, the power source 808 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[0303] Embodiments of the RAN entity 100 may include additional components beyond those shown in Fig. 8 for providing certain aspects of the RAN entity's functionality, including any of the functionality described herein and / or any functionality necessary to support the subject matter described herein. For example, the RAN entity 100 may include user interface equipment to allow input of information into the RAN entity 100 and to allow output of information from the RAN entity 100. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the RAN entity 100.

[0304] As schematically shown in the schematic block diagram for an embodiment of the RAN entity 100 in Fig. 8, the device 100 comprises the memory 804 encoded with instructions that implement at least one of the modules 102, 104, 106 and 108 for performing the steps 302, 304, 306, and 308, respectively.

[0305] Fig. 9 shows a schematic block diagram for an embodiment of the transport node 200. The transport node 200 comprises processing circuitry, e.g., one or more processors 902 for performing the method 400 and memory 904 coupled to the processors 902. For example, the memory 904 may be encoded with instructions that implement at least one of the modules 202, 204, 206, and 208 performing the steps 402, 404, 406, and 408, respectively.

[0306] The one or more processors 902 may be a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, microcode and / or encoded logic operable to provide, either alone or in conjunction with other components of the device 200, such as the memory 904, Telemetry Interworking functionality (TIWF) 201, e.g. by accessing a routing table 912. For example, the one or more processors 902 may execute instructions stored in the memory 904. Such functionality may include providing various features and steps discussed herein, including any of the benefits disclosed herein. The Telefonaktiebolaget LM Ericsson (publ) 48 / 62 301-0276WO

[0307] P111758WO01 13 Dec 2024 expression "the device being operative to perform an action" may denote the transport node 200 being configured to perform the action.

[0308] As schematically illustrated in Fig. 9, the transport node 200 may be embodied by a router, e.g., functioning as an ingress and / or egress of the transport domain 550.

[0309] The transport node 200 includes the processing circuitry 902, its associated memory 904, a communication interface 906, and a power source 908. The communication interface 906 comprises a RAN interface 918 for connecting to one or more RAN entities 100. The communication interface 906 further comprises network ports 916, e.g., Ethernet ports, as the ingress and / or egress to the transport domain 550.

[0310] The mapping between the flow labels and the transport paths may be stored in a routing table 912 of the transport node 200.

[0311] With reference to Fig. 10, in accordance with an embodiment, a communication system 1000 includes a telecommunication network 1010, such as a 3GPP-type cellular or D-MIMO network, which comprises an access network 1011, such as the RAN 500, and a core network 1014. The access network 1011 comprises a plurality of base stations 1012a, 1012b, 1012c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 1013a, 1013b, 1013c. Each base station 1012a, 1012b, 1012c is connectable to the core network 1014 over a wired or wireless connection 1015. A first user equipment (UE) 1091 located in coverage area 1013c is configured to wirelessly connect to, or be paged by, the corresponding base station 1012c. A second UE 1092 in coverage area 1013a is wirelessly connectable to the corresponding base station 1012a. While a plurality of UEs 1091, 1092 are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station 1012.

[0312] Any of the base stations 1012, or functional parts such as a RU and / or DU of it, may embody the device 100.

[0313] Optionally, the telecommunication network 1010 is itself connected to a host computer 1030, which may be embodied in the hardware and / or software of a Telefonaktiebolaget LM Ericsson (publ) 49 / 62 301-0276WO

[0314] P111758WO01 13 Dec 2024 standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. The host computer 1030 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. The connections 1021, 1022 between the telecommunication network 1010 and the host computer 1030 may extend directly from the core network 1014 to the host computer 1030 or may go via an optional intermediate network 1020. The intermediate network 1020 may be one of, or a combination of more than one of, a public, private or hosted network; the intermediate network 1020, if any, may be a backbone network or the Internet; in particular, the intermediate network 1020 may comprise two or more subnetworks (not shown).

[0315] The communication system 1000 of Fig. 10 as a whole enables connectivity between one of the connected UEs 1091, 1092 and the host computer 1030. The connectivity may be described as an over-the-top (OTT) connection 1050. The host computer 1030 and the connected UEs 1091, 1092 are configured to communicate data and / or signaling via the OTT connection 1050, using the access network 1011, the core network 1014, any intermediate network 1020 and possible further infrastructure (not shown) as intermediaries. The OTT connection 1050 may be transparent in the sense that the participating communication devices through which the OTT connection 1050 passes are unaware of routing of uplink and downlink communications. For example, a base station 1012 need not be informed about the past routing of an incoming downlink communication with data originating from a host computer 1030 to be forwarded (e.g., handed over) to a connected UE 1091. Similarly, the base station 1012 need not be aware of the future routing of an outgoing uplink communication originating from the UE 1091 towards the host computer 1030.

[0316] By virtue of the method 300 being performed by any one of the base stations 1012 and routers in the fronthaul of the access network 1011 (i.e., the RAN 500) performing the method 400, the performance of the OTT connection 1050 can be improved, e.g., in terms of increased throughput and / or reduced latency or can be brought into agreement with a QoS requirement. More specifically, the host computer 1030 may indicate to the RAN 500 or the RAN entity 100 or the transport node 200 (e.g., on a network layer) the QoS of the traffic, optionally using the flow labels. Telefonaktiebolaget LM Ericsson (publ) 50 / 62 301-0276WO

[0317] P111758WO01 13 Dec 2024

[0318] As has become apparent from above description, at least some embodiments of the technique can ensure that transport-specific telemetry information 600 is available for RAN entities 100, which can use it for optimization of RAN operation.

[0319] Having access to said telemetry information 600, RAN entities (e.g., RAN nodes) can differentiate transport network issues (i.e., issues caused in the transport domain 550) from radio interface (colloquial: "air interface") issues. Furthermore, embodiments of the technique enable RAN entities 100 to take appropriate or more specific corrective actions for a transport network, e.g., by controlling the transport domain 550 of the RAN 500).

[0320] For example, the RAN entity 100 (e.g., any RAN node) may, based on the received telemetry information, adapt its traffic generation (e.g., reduce traffic allocation) and / or select a different tunnel or transport path to reach another RAN entity 100 (e.g., a RAN endpoint, a radio node or a baseband node). Additionally or alternatively, the RAN entity 100 (e.g. a RAN node or baseband unit) may selectively partition its traffic to maintain service-level agreements (SLAs). For example, the traffic for prioritized radio device (e.g., UEs) or traffic that does not tolerate losses, may be sent over a tunnel or transport path with better telemetry metrics according to the received 306 telemetry information.

[0321] The technique may be implemented in accordance with, or by modifying, at least one of the following technical standard documents.

[0322] Document O-RAN Working Group 4 (Open Fronthaul Interfaces WG), Technical Specification, "Control, User and Synchronization Plane Specification" (O- RAN.WG4.CUS.0-R004-vl6.01), October 2024.

[0323] Document eCPRI Specification V2.0, 2019-05-10, http: / / www.cpri.info / downloads / eCPRI_v_2.0_2019_05_10c.pdf

[0324] Document O-RAN WG9 Technical Specification, "Xhaul Packet Switched

[0325] Architectures and Solutions", https: / / orandownloadsweb.azurewebsites.net / specifications Telefonaktiebolaget LM Ericsson (publ) 51 / 62 301-0276WO P111758WO01 13 Dec 2024

[0326] Document RFC 8972, "Simple Two-Way Active Measurement Protocol Optional Extensions", 2021-01-21, https: / / datatracker.ietf.org / doc / rfc8972 /

[0327] Document RFC 8986, "Segment Routing over IPv6 (SRv6) Network Programming", 2022-05-27, https: / / datatracker.ietf.org / doc / rfc8986 /

[0328] Internet-Draft "Compressed SRv6 Segment List Encoding (CSID)", 2024-11-03, https: / / www.ietf.org / id / draft-ietf-spring-srv6-srh-compression-19.txt

[0329] List of reference signs

[0330] 100 RAN entity, e.g., RU or DU

[0331] 101 Telemetry interworking function (TWIF) consumer

[0332] 102 Telemetry configuring module

[0333] 104 Telemetry requesting module

[0334] 106 Telemetry receiving module

[0335] 108 Transport changing module, e.g., transport controlling module

[0336] 200 Transport node, e.g., router, tunnel endpoint, ingress node, egress node, tunnel gateway, edge device

[0337] 201 Telemetry interworking function (TWIF) producer

[0338] 202 Telemetry collecting module

[0339] 204 Request reception module

[0340] 206 Telemetry sending module

[0341] 208 Transport changing module e.g., transport controlling module

[0342] 300 Method performed by RAN entity

[0343] 302 Step of sending telemetry configuration

[0344] 304 Step of sending telemetry request

[0345] 306 Step of receiving telemetry information

[0346] 308 Step of changing transport configuration, e.g., controlling transport node and / or sending control message Telefonaktiebolaget LM Ericsson (publ) 52 / 62 301-0276WO

[0347] P111758WO01 13 Dec 2024

[0348] 400 Method performed by transport node

[0349] 402 Step of collecting telemetry information, e.g., upon receiving telemetry configuration

[0350] 404 Step of receiving telemetry request

[0351] 406 Step of sending telemetry information

[0352] 408 Step of changing transport configuration e.g., changing routing of data packets in the transport domain

[0353] 500 Radio access network (RAN)

[0354] 550 Transport domain

[0355] 600 Telemetry information collected in the transport domain

[0356] 602 Transport-related telemetry information sent to RAN entity, e.g., application layer data packet comprising the telemetry information

[0357] 802 Processing circuitry of RAN entity, e.g., CPU or GPU

[0358] 804 Recording medium of RAN entity, e.g., memory

[0359] 806 Communication interface

[0360] 808 Power source

[0361] 810 Antenna

[0362] 812 RF transceiver circuitry

[0363] 814 Baseband processing circuitry

[0364] 816 Terminals

[0365] 818 Radio front-end circuitry

[0366] 820 Filters

[0367] 822 Amplifiers

[0368] 902 Processing circuitry of transport node, e.g., CPU or GPU

[0369] 904 Recording medium of transport node, e.g., memory

[0370] 906 Communication interface

[0371] 908 Power source Telefonaktiebolaget LM Ericsson (publ) 53 / 62 301-0276WO

[0372] P111758WO01 13 Dec 2024

[0373] 912 Routing table

[0374] 916 Network port, e.g., Ethernet port

[0375] 918 RAN interface

[0376] 1000 Communication system

[0377] 1010 Telecommunication network

[0378] 1011 Access network

[0379] 1012 Base station

[0380] 1013 Coverage area

[0381] 1014 Core network

[0382] 1015 Wireless connection

[0383] 1020 Network

[0384] 1021, 1022 Outer connections

[0385] 1030 Host computer

[0386] 1050 OTT connection

[0387] 1091, 1092 Radio device, e.g., UE

[0388] Abbreviations

[0389] RU Radio Unit

[0390] DU Digital Unit, e.g., Distributed Unit

[0391] Rl, R2, R3, R4, R5 Router

[0392] TEP Tunnel Endpoint

[0393] TIWF Telemetry Interworking Function

[0394] SRv6 Segment Routing over IPv6

[0395] SID Segment Identifier

[0396] QoS Quality of Service

[0397] RAN flow Radio Access Network flow

[0398] SRH Segment Routing Header

[0399] O-RU O-RAN Radio Unit

[0400] O-DU O-RAN Distributed Unit

[0401] CU Centralized Unit

[0402] FH Fronthaul

[0403] RRU Remote Radio Unit Telefonaktiebolaget LM Ericsson (publ) 54 / 62 301-0276WO P111758WO01 13 Dec 2024

[0404] RRH Remote Radio Head

[0405] BBU Baseband Unit

[0406] MH Midhaul

[0407] BH Backhaul

[0408] CN Core Network

[0409] UE User Equipment

[0410] OTT Over the Top

[0411] CPU Central Processing Unit

[0412] GPU Graphics Processing Unit

[0413] IP Internet protocol

[0414] MIB Management information base

[0415] NMS Network management system

[0416] STAMP Simple Two-Way Active Measurement Protocol

[0417] U-Plane User plane

[0418] SLA Service level agreement

[0419] Many advantages of the present invention will be fully understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the units and devices without departing from the scope of the invention and / or without sacrificing all of its advantages. Since the invention can be varied in many ways, it will be recognized that the invention should be limited only by the scope of the following claims.

Claims

Telefonaktiebolaget LM Ericsson (publ) 55 / 62 301-0276WOP111758WO01 13 Dec 2024Claims1. A method (300) performed by a RAN entity (100; 1012) of a radio access network, RAN (500), the method (300) comprising: receiving (306), from at least one transport node (200) of a transport domain (550) of the RAN (500), transport-related telemetry information indicative of telemetry of the transport domain (550).

2. The method (300) of claim 1, wherein at least one of: the transport node (200) is configured to perform a protocol of a network layer and / or a transport layer within the transport domain (550); the transport node (200) operates outside of a radio protocol stack of the RAN (500); the RAN entity (100; 1012) performs a protocol of a radio protocol stack of the RAN (500); and the RAN entity (100; 1012) operates outside the transport domain (550).

3. The method (300) of claim 1 or 2, wherein the transport domain (550) comprises at least one of: a packet-based fronthaul of the RAN; and a transport network connecting the RAN entity (100; 1012) of the RAN (500) to one or more further RAN entities of the RAN (500).

4. The method (300) of any one of claims 1 to 3, wherein the at least one transport node (200) in the transport domain (550) comprises an edge node, or each edge node, of the transport domain (550).

5. The method (300) of any of claims 1 to 4, wherein the transport node (200) comprises a telemetry interworking function, TIWF (201), and the transport- related telemetry information is received (306) from the TIWF (201) of the transport node (200); and / or wherein the method (300) further comprises: sending (302), to the transport node (200), a configuration message that configures a TIWF (201) at the transport node (200) to collect transport-related telemetry information from the transport domain (550), and send the collected transport-related telemetry information to the RAN entity (100; 1012).Telefonaktiebolaget LM Ericsson (publ) 56 / 62 301-0276WOP111758WO01 13 Dec 20246. The method (300) of any of claims 1 to 5, further comprising: sending (304), by the RAN entity (100; 1012), a telemetry request to the transport node (200) in the transport domain (550) to request the transport- related telemetry information.

7. The method (300) of claim 6, wherein the telemetry request is sent (304) by encoding a telemetry indicator in a header field of a data packet sent from the RAN entity (100; 1012) to the transport node (200) in the transport domain (550).

8. The method (300) of any of claims 1 to 7, wherein the transport-related telemetry information includes at least one of: a packet loss rate associated with the transport domain (550); a packet latency associated with the transport domain (550); and a jitter associated with the transport domain (550).

9. The method (300) of any of claims 1 to 8, further comprising: changing (308), based on the received (306) transport-related telemetry information, at least one operational parameter of the RAN entity (100; 1012) and / or the transport node (200).

10. The method (300) of claim 9, wherein the changing (308) of the at least one operational parameter of the transport node (200) comprises: sending, based on the received (306) transport-related telemetry information, a control message to the transport node (200), wherein the control message triggers a change (408) of at least one operational parameter of the transport node (200).

11. The method (300) of claim 9 or 10, wherein the change (308; 408) of the at least one operational parameter comprises at least one of: selecting, based on the received (306) transport-related telemetry information, a different transport path in the transport domain (550) for RAN traffic; and reallocating, based on the received (306) transport-related telemetry information, RAN traffic to alternative transport paths outside of the transport domain (550) of the transport node (200).Telefonaktiebolaget LM Ericsson (publ) 57 / 62 301-0276WO P111758WO01 13 Dec 202412. The method (300) of any one of claims 1 to 11, wherein the RAN entity (100;1012) is a digital unit, DU, or a centralized unit, CU, of the RAN (500).

13. The method (300) of any of claims 1 to 12, wherein the transport domain (550) comprises a transport tunnel.

14. The method (300) of claim 13, wherein the transport node (200) is a tunnel endpoint, TEP, node of the transport tunnel and / or wherein the transport tunnel comprises a plurality of routing segments and the transport node (200) is a router connecting at least two of the routing segments.

15. The method (300) of any of claims 1 to 14, wherein the transport domain (550) comprises one or more segments for segment routing, SR, and / or wherein the transport node (200) is configured to perform segment routing, SR, in the transport domain (550).

16. The method (300) of claim 15, wherein the segment routing, SR, uses SR over internet protocol version 6, SRv6, or SR over multi-protocol label switching, SR-MPLS.

17. The method (300) of claim 15 or 16, further comprising: controlling (308) the SR performed by the transport node (200) for data packets of the RAN entity (100; 1012) using flow labels included in the data packets based on the received (306) transport-related telemetry information.

18. The method (300) of any one of claims 1 to 17, wherein the received (306) transport-related telemetry information comprises different values associated with different flow labels in a network layer header of data packets for the RAN entity (100; 1012).Telefonaktiebolaget LM Ericsson (publ) 58 / 62 301-0276WO P111758WO01 13 Dec 202419. The method (300) of any one of claims 1 to 18, wherein the RAN entity (100; 1012) includes flow labels in network layer headers of data packets, and wherein at least one of: a mapping between RAN flows of the RAN (500) and the flow labels included in the network layer headers is dependent on the received (306) transport-related telemetry information; and a mapping between the flow labels included in the network layer headers and transport paths of the transport domain (550) is dependent on the received (306) transport-related telemetry information.

20. The method (300) of any of claims 1 to 19, further comprising: partitioning RAN traffic into multiple traffic classes based on criteria, optionally the criteria depending on at least one of a quality of service (QoS) requirement, a type of traffic, a connection type, and service characteristics of the RAN traffic; and controlling (308) the transport node (200) to route the RAN traffic of each of the traffic classes over transport paths in the transport domain (550) selected based on the transport-related telemetry information received (306) for each of the transport paths fulfilling the criteria of the respective traffic classes.

21. A method (400) performed by a transport node (200) in a transport domain (550) of a radio access network, RAN (500), the method (400) comprising: sending (406), to at least one RAN entity (100; 1012) of the RAN (500), transport-related telemetry information indicative of telemetry of the transport domain (550).

22. The method (400) of claim 21, wherein the sending (406) of the transport- related telemetry information comprises sending, optionally multicasting, the transport-related telemetry information to a plurality of RAN entities (100) in the RAN (500).Telefonaktiebolaget LM Ericsson (publ) 59 / 62 301-0276WOP111758WO01 13 Dec 202423. The method (400) of claim 21 or 22, wherein the transport node (200) comprises a telemetry interworking function, TIWF (201), and the method (400) further comprises: collecting (402), by the TIWF (201), transport-related telemetry information from the transport domain (550), optionally responsive to receiving a configuration message from the at least one RAN entity (100; 1012); and sending (406), by the TIWF (201), the collected transport-related telemetry information to the at least one RAN entity (100; 1012).

24. The method (400) of any one of claims 21 to 23, further comprising: receiving (404), from the at least one RAN entity (100; 1012), a telemetry request requesting the transport-related telemetry information; and responsive to the telemetry request, collecting (402) the transport-related telemetry information from the transport domain (550).

25. The method (400) of claim 23 or 24, wherein the transport node (200) collects (402) the transport-related telemetry information by measuring transportspecific telemetry data within the transport domain (550); and wherein the method (400) further comprises: translating, by the TIWF (201), the transport-specific telemetry data into RAN-specific telemetry parameters to be sent (406) as the transport-related telemetry information to the at least one RAN entity (100; 1012).

26. The method (400) of any of claims 23 to 25, wherein the transport node (200) collects (402) the transport-related telemetry information for a bi-directional path comprising a pair of reversely configured unidirectional transport tunnels in the transport domain (550).

27. The method (400) of any of claims 21 to 26, further comprising the features and steps of any of claims 2 to 19, or features and steps corresponding thereto.

28. A computer program product comprising program code portions for performing the steps of any one of the claims 1 to 20 and / or 21 to 27 when the computer program product is executed on one or more computing devices (802; 902), optionally stored on a computer-readable recording medium (804; 904).Telefonaktiebolaget LM Ericsson (publ) 60 / 62 301-0276WOP111758WO01 13 Dec 202429. A RAN entity (100; 1012) comprising memory (804) operable to store instructions and processing circuitry (802) operable to execute the instructions, such that the RAN entity (100; 1012) is operable to: receive, from at least one transport node (200) of a transport domain (550) of the RAN (500), transport-related telemetry information indicative of telemetry of the transport domain (550).

30. The RAN entity (100; 1012) of claim 29, further comprising any one of the features and being operable to perform any one of the steps of any of claims 2 to 20.

31. A RAN entity (100; 1012) for operating a fronthaul in a radio access network, RAN (500), the RAN entity (100; 1012) being configured to: receive, from at least one transport node (200) of a transport domain (550) of the RAN (500), transport-related telemetry information indicative of telemetry of the transport domain (550).

32. The RAN entity (100; 1012) of claim 31, further comprising any one of the features and being configured to perform any one of the steps of any of claims 2 to20.

33. A transport node (200) comprising memory (904) operable to store instructions and processing circuitry (902) operable to execute the instructions, such that the Transport node (200) is operable to: send, to at least one RAN entity (100; 1012) of the RAN (500), transport- related telemetry information indicative of telemetry of the transport domain (550).

34. The transport node (200) of claim 33, further comprising any one of the features and being operable to perform any one of the steps of any of claims 22 to 27.

35. A transport node (200) for operating a fronthaul in a radio access network, RAN (500), the Transport node (200) being configured to: send, to at least one RAN entity (100; 1012) of the RAN (500), transport- related telemetry information indicative of telemetry of the transport domain (550).Telefonaktiebolaget LM Ericsson (publ) 61 / 62 301-0276WO P111758WO01 13 Dec 202436. The transport node (200) of claim 35, further comprising any one of the features and being configured to perform any one of the steps of any of claims 22

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