EP-4271028-B1 - METHOD FOR TRANSFERRING AN ACCESS NODE BY A NEAR-REAL-TIME RADIO ACCESS NETWORK INTELLIGENT CONTROLLER

EP4271028B1EP 4271028 B1EP4271028 B1EP 4271028B1EP-4271028-B1

Inventors

GEBERT, JENS
OZTURK, ECE
FLINCK, HANNU
BULAKCI, Ömer

Dates

Publication Date: 20260513
Application Date: 20230426

Claims (14)

An apparatus comprising: means for implementing a near-real-time radio access network intelligent controller; means for detecting (800) an event triggering a need for transfer of control of at least one access node from said near-real-time radio access network intelligent controller to a target near-real-time radio access network intelligent controller; means for determining (802) an address of the target near-real-time radio access network intelligent controller; means for establishing (804) an interface between said near-real-time radio access network intelligent controller and the target near-real-time radio access network intelligent controller; and means for carrying out (806) the transfer of the control of the at least one access node from said near-real-time radio access network intelligent controller to the target near-real-time radio access network intelligent controller.
The apparatus according to claim 1, wherein said means for carrying out the transfer of the control of the at least one access node comprises means for transferring a context of the at least one access node from said near-real-time radio access network intelligent controller to the target near-real-time radio access network intelligent controller.
The apparatus according to claim 2, wherein the context of the at least one access node comprises one or more of the following: a list of access nodes to be transferred, a list of configurations for each access node, a list of services and their mappings to interface-specific functions in each access node, and a list of active policies applied in each access node.
The apparatus according to any preceding claim, wherein said event triggering the need for the transfer of the control of the access node is one of the following: an internal event of said near-real-time radio access network intelligent controller; an external event of said near-real-time radio access network intelligent controller; a command from another logical or physical network element to said near-real-time radio access network intelligent controller to initiate the transfer of the control of the access node.
The apparatus according to any preceding claim, wherein said means for determining the address of the target near-real-time radio access network intelligent controller comprises means for obtaining the address from another logical or physical network element.
The apparatus according to any preceding claim, wherein said means for determining the address of the target near-real-time radio access network intelligent controller comprises means for receiving the address from operations, administration and maintenance, OAM, functionality of the network.
The apparatus according to any preceding claim, wherein said means for determining the address of the target near-real-time radio access network intelligent controller comprises means for carrying out a query about the address in a database.
The apparatus according to any preceding claim, wherein the control of the at least one access node is configured to be transferred via a direct interface between the source near-real-time radio access network intelligent controller and target near-real-time radio access network intelligent controller.
The apparatus according to any preceding claim, wherein the control of the at least one access node is configured to be transferred between the source near-real-time radio access network intelligent controller and target near-real-time radio access network intelligent controller via one or more access nodes.
The apparatus according to any preceding claim, wherein the control of the at least one access node is configured to be transferred between the source near-real-time radio access network intelligent controller and target near-real-time radio access network intelligent controller via a non-real-time radio access network intelligent controller.
The apparatus of any preceding claim wherein the means comprises at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.
A method comprising: detecting (800), by a near-real-time radio access network intelligent controller, an event triggering a need for transfer of control of at least one access node from said near-real-time radio access network intelligent controller to a target near-real-time radio access network intelligent controller; determining (802), by said near-real-time radio access network intelligent controller, an address of the target near-real-time radio access network intelligent controller; establishing (804) an interface between said near-real-time radio access network intelligent controller and the target near-real-time radio access network intelligent controller; and carrying out (806) the transfer of the control of the at least one access node from said near-real-time radio access network intelligent controller to the target near-real-time radio access network intelligent controller.
The method according to claim 12, comprising transferring a context of the at least one access node from said near-real-time radio access network intelligent controller to the target near-real-time radio access network intelligent controller.
The method according to claim 13, wherein the context of the at least one access node comprises one or more of the following: a list of access nodes to be transferred, a list of configurations for each access node, a list of services and their mappings to interface-specific functions in each access node, and a list of active policies applied in each access node.

Description

TECHNICAL FIELD The present invention relates to an access node transfer procedure among network entities. BACKGROUND 5G specifications provide an option to split the internal structure of an access node gNodeB (gNB) into entities called CU (Central Unit) and one or more DUs (Distributed Unit), which are connected by a F1 interface. There may also be a RAN (Radio Access Network) intelligent controller (RIC) connected through an E2 interface to the nodes gNB-DU and gNB-CU. RIC is a logical function that, according to O-RAN (Open Radio Access Network) architecture (as defined by the O-RAN alliance), may be further divided into functions of a non-real-time (non-RT) RIC and a near-real-time (near-RT) RIC with the non-RT RIC carrying out service management and orchestration (SMO) operations for one or more near-RT RIC over the A1 interface. The near-real-time RIC enables near-real-time control and optimization of various RAN elements (referred to as E2 Nodes) and resources via fine-grained data collection and actions over E2 interface. An E2 Node may be connected to only one Near-RT RIC. Partly from the same reason, there is no interface specified between two Near-RT RIC's nor a procedure defined for a handover of the E2 Node from the first Near-RT RIC to the second Near-RT RIC. However, there may arise a situation, where due to the mobility of the E2 Node, the E2 Node may enter into a region managed by another Near-RT RIC. The E2 Node cannot, nevertheless, seamlessly change its association from previous Near-RT RIC to a new Near-RT RIC. WO 2020/242987 A1 discloses methods for load balancing and mobility robustness in cellular systems. A network entity such as a near-RT RIC may receive ranges of handover (HO) parameters and/or performance targets for a mobility robustness optimization (MRO) function and/or a load balancing optimization (LBO) function from a service management and orchestration framework (SMOFW) and receive and analyze HO related performance measurements and/or cell load measurements from an open RAN (O-RAN) distributed unit (O-DU) or centralized unit (O-CU). The near-RTI RIC, based on the analysis, may request the SMOFW to change virtualized resources, request the O-DU update HO parameters, and/or request the O-DU/ O-CU update UE selection, cell selection and/or handover parameters. "Understanding O-RAN: Architecture, Interfaces, Algorithms, Security, and Research Challenges", by M. Polese et al, Arxiv.org, Cornell University Library, 2 February 2022, discloses an introduction of O-RAN, its architecture, its interfaces, and workflows for researchers and practitioners in the wireless community. The main research challenges are discussed, and early research results are reviewed. CN 111 642 011 discloses a method for carrying out radio resource management and an nRT RIC. The method is implemented by the steps that: a first nRT RIC function management entity transmits measurement information of access network equipment and/or load information of the access network equipment to a second nRT RIC function management entity; then, the second nRT RIC function management entity carries out radio resource management on a terminal between the access network equipment according to the measurement information and/or the load information, and transmits information obtained in the radio resource management process to the first nRT RIC function management entity; and the first nRT RIC function management entity carrying out wireless resource management on the terminal accessed to the access network equipment according to the information. SUMMARY Now, an improved method and technical equipment implementing the method has been invented, by which the above problems are alleviated. Various aspects include an apparatus and a method, which are characterized by what is stated in the independent claims. Various details of the embodiments are disclosed in the dependent claims and in the corresponding images and description. The scope of protection sought for various embodiments of the invention is set out by the independent claims. The embodiments and features, if any, described in this specification that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various embodiments of the invention. According to a first aspect, there is provided an apparatus comprising means for implementing a near-real-time radio access network intelligent controller; means for detecting an event triggering a need for transfer of control of at least one access node from said near-real-time radio access network intelligent controller to a target near-real-time radio access network intelligent controller; means for determining an address of the target near-real-time radio access network intelligent controller; means for establishing an interface between said near-real-time radio access network intelligent controller and the target near-real-time radio access network intelligent contro