Handover in non-terrestrial networks (NTN) with radio frequency (RF) repeater assistance

Abstract

Embodiments of the present disclosure relate to handover in non-terrestrial networks (NTNs) with radio frequency (RF) repeater assistance. A method is provided that includes performing a handover of one or more user equipments (UEs) and at least one RF repeater serving the UEs from a source node to a target node. The method includes receiving, at the target node, assistance information related to the handover of the UE(s) or the RF repeater(s). The method includes making a determination, based on the assistance information, regarding: use of the RF repeater(s) to serve the UE(s), and at least one beam of the RF repeater(s) to serve each of the at least one UE. And based on the determination, the method includes providing, by the target node, radio access services to the UE(s), with the RF repeater(s) used to serve the UE(s) at least one UE for radio transmissions from / to the target node.

Description

Technical Field

[0001] This disclosure generally relates to telecommunications, and more particularly to radio frequency (RF) repeater-assisted non-terrestrial networks (NTNs) in telecommunications systems. Background Technology

[0002] A telecommunications system can be viewed as a facility that enables a communication session between two or more entities (such as user terminals, base stations, and / or other nodes) by providing carriers between various entities involved in the communication path. For example, a telecommunications system can be provided through a communication network and one or more compatible communication devices. The communication session may include, for example, communication of data carrying communications such as voice, video, email, text messages, multimedia, and / or content data. Non-limiting examples of the services provided include two-way or multi-way calling, data communication or multimedia services, and access to data network systems such as the Internet.

[0003] In a wireless telecommunications system, at least a portion of a communication session between at least two stations occurs via a wireless link. Examples of wireless telecommunications systems include Public Land Mobile Networks (PLMNs), satellite-based communication systems, and various wireless local area networks (WLANs). Some wireless systems can be divided into cells and are therefore often referred to as cellular systems.

[0004] Users can access telecommunications systems using appropriate communication equipment or terminals. A user's communication equipment may be referred to as user equipment (UE) or user facilities. The communication equipment has appropriate signal receiving and transmitting means for enabling communication, such as access to a communication network or direct communication with other users. The communication equipment can access a carrier provided by a station (e.g., a base station in a cell) and transmit and / or receive communication on that carrier.

[0005] Telecommunications systems and associated equipment typically operate according to a given standard or specification that defines what the various entities associated with the communication system are allowed to do and how they should operate. The communication protocols and / or parameters used to connect the various entities are also usually defined. An example of a telecommunications system is the Universal Mobile Telecommunications System (UMTS). Other examples of telecommunications systems are Long Term Evolution (LTE), LTE-Advanced, and so-called 5G or New Radio (NR) networks. NR is being standardized by the 3rd Generation Partnership Project (3GPP). Summary of the Invention

[0006] The example implementations of this disclosure relate to telecommunications, and more specifically to the deployment of radio frequency (RF) repeaters-assisted non-terrestrial networks (NTNs) in telecommunications systems. This disclosure includes, but is not limited to, the following example implementations.

[0007] Some example implementations provide an apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory and execute instructions to cause the apparatus to at least: receive radio access service from a source node, wherein at least one radio frequency (RF) repeater is used to serve one or more user equipments (UEs) for radio transmissions from or to the source node; perform a handover of the one or more UEs or the at least one RF repeater from the source node to a target node; and send auxiliary information relating to the handover to the target node, the auxiliary information being used to assist the target node in making a determination regarding: using the at least one RF repeater to serve the one or more UEs, and at least one beam of the at least one RF repeater for serving each of the at least one UE.

[0008] Some example implementations provide a method comprising: receiving radio access service from a source node, wherein at least one radio frequency (RF) repeater is used to serve one or more user equipments (UEs) for radio transmissions from or to the source node; performing a handover of the one or more UEs or the at least one RF repeater from the source node to a target node; and sending auxiliary information relating to the handover to the target node, the auxiliary information being used to assist the target node in making a determination regarding: using the at least one RF repeater to serve the one or more UEs, and at least one beam of the at least one RF repeater for serving each of the at least one UE.

[0009] Some example implementations provide an apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory and execute the instructions such that the apparatus at least: provides radio access service from a source node, wherein at least one radio frequency (RF) repeater is used to serve one or more user equipments (UEs) for radio transmissions from or to the source node; initiates a handover of the one or more UEs and the at least one RF repeater from the source node to a target node; and sends to the target node auxiliary information relating to the handover of the one or more UEs or the at least one RF repeater, the auxiliary information being used to assist the target node in making a determination regarding: using the at least one RF repeater to serve the one or more UEs, and at least one beam of the at least one RF repeater for serving the at least one UE.

[0010] Some example implementations provide a method comprising: accessing the at least one memory and executing instructions to cause the device to at least: provide radio access service from a source node, wherein at least one radio frequency (RF) repeater is used to serve one or more user equipments (UEs) for radio transmissions from or to the source node; initiate a handover of the one or more UEs and the at least one RF repeater from the source node to a target node; and send to the target node auxiliary information relating to the handover of the one or more UEs or the at least one RF repeater, the auxiliary information being used to assist the target node in making a determination regarding: using the at least one RF repeater to serve the one or more UEs, and at least one beam of the at least one RF repeater for serving the at least one UE.

[0011] Some example implementations provide an apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory and execute the instructions to cause the apparatus to at least: perform a handover of one or more user equipment (UEs) and at least one radio frequency (RF) repeater for serving the one or more UEs from a source node to a target node; receive at the target node auxiliary information relating to the handover of the one or more UEs or the at least one RF repeater; based on the auxiliary information, make a determination regarding: using the at least one RF repeater to serve the one or more UEs, and at least one beam of the at least one RF repeater for serving each of the at least one UE; and based on the determination, provide radio access service from the target node to the one or more UEs, wherein the at least one RF repeater is used to serve at least one of the one or more UEs for radio transmissions from or to the target node.

[0012] Some example implementations provide a method comprising: performing a handover of one or more user equipment (UEs) and at least one radio frequency (RF) repeater for serving the one or more UEs from a source node to a target node; receiving at the target node auxiliary information relating to the handover of the one or more UEs or the at least one RF repeater; based on the auxiliary information, making a determination regarding: using the at least one RF repeater to serve the one or more UEs, and at least one beam of the at least one RF repeater for serving each of the at least one UE; and based on the determination, providing radio access service from the target node to the one or more UEs, wherein the at least one RF repeater is used to serve at least one of the one or more UEs for radio transmissions from or to the target node.

[0013] These and other features, aspects, and advantages of this disclosure will become apparent from the following detailed description and the accompanying drawings, which are briefly described below. This disclosure includes any combination of two, three, four, or more features or elements set forth herein, whether or not such features or elements are explicitly combined or otherwise described in the particular example implementation described herein. This disclosure is intended to be read holistically, such that any separable feature or element of this disclosure shall be considered composable in any aspect and example implementation thereof, unless the context of this disclosure expressly provides otherwise.

[0014] Therefore, it should be understood that the content of this invention is provided merely to summarize some exemplary implementations in order to provide a basic understanding of some aspects of this disclosure. Consequently, it should be understood that the above-described exemplary implementations are merely examples and should not be construed as limiting the scope or spirit of this disclosure in any way. Other exemplary implementations, aspects, and advantages will become apparent from the following detailed description taken in conjunction with the accompanying drawings, which illustrate by way of example the principles of some of the described exemplary implementations. Attached Figure Description

[0015] An example implementation of this disclosure has been described in general terms. Reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and in which: Figure 1 The present disclosure illustrates a telecommunications system comprising one or more Public Land Mobile Networks (PLMNs) coupled to one or more external data networks, implemented according to some examples. Figure 2 The deployment of a PLMN comprising one or more user equipment (UE) is illustrated according to some examples; Figure 3 An example network control repeater (NCR) is shown. Figure 4 An example of a reconfigurable smart surface (RIS) is shown. Figure 5 The implementation based on some examples is shown. Figure 2 Deployment of non-terrestrial networks (NTNs) in the deployment; Figure 6 An example of satellite handover in an NTN is shown, based on some examples; Figure 7A , Figure 7B and Figure 7C The diagram illustrates a signaling diagram of one or more processes in a deployment including UE-transparent RIS and RIS-transparent UE, implemented according to some examples; Figure 8A , Figure 8B and Figure 8CThe diagram illustrates a signaling diagram of one or more processes in a UE-aware RIS deployment implemented according to some examples; Figure 9A , Figure 9B and Figure 9C The diagram illustrates a signaling diagram of one or more processes in a RIS-aware UE deployment, implemented according to some examples. Figure 10 This is a flowchart illustrating the individual steps in a method implemented according to some examples; Figure 11A and Figure 11B This is a flowchart illustrating the individual steps in a method implemented based on some other examples; Figure 12 It is a flowchart illustrating the various steps in a method implemented according to several other examples; and Figure 13 The apparatus is shown based on some examples. Detailed Implementation

[0016] Some implementations of this disclosure will now be described more fully below with reference to the accompanying drawings, which illustrate some, but not all, of these implementations. In fact, various implementations of this disclosure may be implemented in many different forms and should not be construed as limited to the implementations set forth herein; rather, these example implementations are provided to make this disclosure thorough and complete and to fully convey the scope of this disclosure to those skilled in the art. The same reference numerals throughout refer to the same elements.

[0017] Unless otherwise stated or clarified from the context, references to “first,” “second,” etc., should not be construed as implying a particular order. A feature described as being above another feature (unless otherwise stated or clarified from the context) may alternatively be below it, and vice versa; and similarly, a feature described as being to the left of another feature may alternatively be to the right of it, and vice versa. Furthermore, while this document may refer to quantitative measurements, numerical values, geometric relationships, etc., any one or more of these (if not all) may be absolute or approximate, unless otherwise stated, to account for acceptable variations that may occur, such as those due to engineering tolerances, etc.

[0018] As used herein, unless otherwise stated or clarified from the context, "OR" in the operand set is "inclusive OR," and thus true if and only if one or more operands are true, not "XOR" which is false if all operands are true. Therefore, for example, "[A] OR [B]" is true if [A] is true, or if [B] is true, or if both [A] and [B] are true. Furthermore, the articles "a" and "one" indicate "one or more," unless otherwise stated or clearly indicated from the context to the singular form. Additionally, it should be understood that, unless otherwise stated, the terms "data," "content," "digital content," "information," and similar terms are sometimes used interchangeably. The term "network" can refer to a group of interconnected computers, including clients and servers; and within a network, these computers can be interconnected directly or indirectly by various means, including via one or more switches, routers, gateways, access points, etc.

[0019] This disclosure discusses systems and architectures that are broadly applicable to a wide range of technologies while using specific terminology. For example, while this disclosure may refer to technologies from 3GPP, such as Global System for Mobile Communications (GSM), UMTS, LTE, Advanced LTE, 5G NR, 5G Advanced, and 6G, this disclosure is equally relevant to non-3GPP technologies such as IEEE 802, Bluetooth, and Bluetooth Low Energy. The exemplary implementations of this disclosure described herein also refer to Public Land Mobile Networks (PLMNs) and Mobile Network Operators (MNOs), but the exemplary implementations are similarly applicable to Standalone Non-Public Networks (SNPNs) and the private entities operating these networks. Furthermore, although some examples and figures focus on Radio Access Networks (RANs) and 3GPP access, the exemplary implementations are applicable to any type of network access. This includes not only 5G or 6G 3GPP access, but also non-3GPP access, such as wired access, untrusted non-3GPP access, and trusted non-3GPP access using the Radio Access Gateway Function (W-AGF), non-3GPP interoperability function (N3IWF), or trusted non-3GPP gateway function (TNGF) connected to the 5G or 6G core network.

[0020] Furthermore, as used in this application, the term "circuit" may refer to one or more of the following: (a) a hardware circuit implementation only (such as an implementation in analog and / or digital circuits only); (b) a combination of hardware circuits and software, such as (if applicable): (i) a combination of analog and / or digital hardware circuits with software / firmware, and (ii) any part of hardware processors with software (including digital signal processors), software, and memory, which work together to enable a device such as a mobile phone or server to perform various functions; or (c) hardware circuits and / or processors, such as microprocessors or a portion thereof, which require software (e.g., firmware) to operate, but may be absent when operation is not required.

[0021] The above definition of "circuit" applies to all uses of the term in this application, including in any claim. As another example, as used herein, the term "circuit" also covers only hardware circuitry or processors (or processors) or a portion thereof and its accompanying software and / or firmware implementations. For example, if applicable to a particular claim element, the term "circuit" also covers baseband integrated circuits or processor integrated circuits for mobile devices or similar integrated circuits in servers, cellular network devices, or other computing or network devices.

[0022] Figure 1 A telecommunications system 100 implemented according to various examples of this disclosure is illustrated. A telecommunications system typically includes one or more telecommunications networks. As shown, for example, the system includes one or more PLMNs 102 coupled to one or more other external data networks 104—particularly including wide area networks (WANs), such as the Internet. As will be understood, PLMNs can be deployed in a variety of different ways. In particular, some deployments of 4G LTE and 5G NR are considered standalone (SA) deployments. Other deployments combine 4G LTE and 5G technologies and are referred to as non-standalone (NSA) deployments.

[0023] Each PLMN in PLMN 102 includes a core network (CN) 106 backbone, such as the Evolved Packet Core (EPC) for 4G LTE, the 5G Core Network (5GC) (sometimes referred to as NGC) for 5G NR, and the 6G Core Network (6GC); and each core network in the core network is coupled to the Internet to one or more RANs 108, air interfaces, etc., implementing one or more Radio Access Technologies (RATs). Examples of these RANs include the Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) for 4G LTE, the Next Generation Radio Access Network (NG-RAN) for 5G NR, and the 6G RAN. As used herein, “network equipment” refers to any suitable equipment on the network side of a telecommunications network. Examples of suitable network equipment are described in more detail below.

[0024] Examples of RATs include 3GPP radio access technologies such as GSM, CDMA2000 1xEV-DO (HRPD), CDMA2000 1x (1xRTT), UTRA, E-UTRA, 5G NR, 5G Advanced, and 6G. Other examples of RATs include IEEE 802 technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.15 (including 802.15.1 (WPAN / Bluetooth), 802.15.4 (Zigbee), and 802.15.6 (WBAN)), Bluetooth, Bluetooth Low Energy (BLE), Ultra Wideband (UWB), etc. Generally, RAT can refer to any 2G, 3G, 4G, 5G, 6G, or higher generation RAT and its different versions, as well as any other RAT that can be configured to interoperate with such mobile communication technologies to provide access to CN106 of the MNO.

[0025] Telecommunication system 100 also includes one or more radio units, which may be referred to as user equipment (UE) 110, terminal equipment, terminal gear, mobile station, etc. A UE is typically a device configured to communicate with network equipment in the telecommunications network or another UE. A UE may be a portable computer (e.g., laptop computer, notebook computer, tablet computer), a mobile phone (e.g., cell phone, smartphone), a wearable computer (e.g., smartwatch), etc. In other examples, a UE may be an Internet of Things (IoT) device, an Industrial IoT (IIoT) device, a vehicle equipped with vehicle-to-everything (V2X) communication technology, etc. In some examples, as referenced by 3GPP, a UE may be a narrowband IoT (NB-IoT) device, an enhanced machine-type communication (eMTC) device, a redcap device, an environmental IoT device, etc.

[0026] In operation, these UEs 110 can connect to one or more RANs in RAN 108 based on their specific RAT, thereby accessing a specific CN 106 of PLMN 102, or accessing one or more external data networks 104 (e.g., the Internet). External data networks can provide Internet access, operator services, third-party services, etc. For example, the International Telecommunication Union (ITU) has classified 5G mobile network services into three categories: enhanced mobile broadband (eMBB), ultra-reliable and low-latency communications (URLLC), and massive machine-type communications (mMTC) or massive Internet of Things (MIoT).

[0027] In various examples, RAN108 can be configured as one or more macro cells, micro cells, pico cells, femto cells, etc. RAN typically includes one or more RAN nodes that interact with UE110. In various examples, RAN nodes can be referred to as base stations (BS), access points (APs), base transceivers (BTSs), node Bs (NBs), evolved NBs (eNBs), macro BSs (NBs (MNBs) or eNBs (MeNBs)), home BSs (NBs (HNBs) or eNBs (HeNBs)), next-generation NBs (gNBs), enhanced gNBs (en-gNBs), next-generation eNBs (ng-eNBs), etc. The term "gNB" in 5G NR can correspond to the eNB in ​​4G LTE. Furthermore, NG RAN nodes can refer to either gNBs or ng-eNBs.

[0028] RAN108 may include some type of network control / management entity responsible for controlling RAN nodes. The network control / management entity and RAN nodes may be separate or integrated into a single device. The network control / management entity may include processing circuitry configured to perform various management functions, etc. The processing circuitry may be associated with memory, computer-readable storage media, or a database for maintaining information required for management functions.

[0029] Figure 2The diagram illustrates a PLMN102 deployment, such as a 5G NR deployment or a 6G deployment. As shown, RAN108 (e.g., NG-RAN, 6G RAN) includes one or more gNBs202 (RAN nodes) configured to connect one or more UEs110 to the RAN, thereby accessing CN106 (e.g., 5GC, 6GC). In some deployments, the operation of gNBs or other RAN nodes can be distributed or functionally split into components including one or more Remote Radio Headers (RRHs) or Radio Units (RUs) and Baseband Units (BBUs); and in some architectures, the BBU can be split into a Central / Centralized Unit (CU) 204 (Central Node) and a Distributed Unit (DU) 206 (Distributed Node). A CU can be, for example, a server, host, or node. In some architectures, RRHs / RUs and DUs can be co-located. Node operation can also be distributed among multiple servers, hosts, or nodes.

[0030] It should also be understood that the distribution of work between core network operations and RAN node operations can vary depending on the implementation. The network architecture can be based on so-called CU-DU splitting. One gNB-CU (CU204) can control one or more gNB-DUs (DU206). A gNB-CU can control multiple spatially separated gNB-DUs, at least acting as transmit / receive (Tx / Rx) nodes. However, in some example implementations, a gNB-DU may include, for example, the Radio Link Control (RLC), Medium Access Control (MAC) layer, and Physical (PHY) layer, while the gNB-CU may include layers above the RLC layer, such as the Packet Data Convergence Protocol (PDCP) layer, Radio Resource Control (RRC), and Internet Protocol (IP) layer. Other functional splitting is also possible. Those skilled in the art are considered familiar with the OSI model and the functions within each layer.

[0031] In some example implementations, the server or CU204 can generate a virtual network through which the server communicates with the radio nodes. Typically, virtual networking can involve the process of combining hardware and software network resources and functions into a single software-based management entity (virtual network). Such a virtual network can provide flexible operational distribution between the server and the radio head ends / nodes. In practice, any digital signal processing task can be performed within the CU or DU206, and the boundary for transferring responsibility between the CU and DU can be chosen depending on the implementation.

[0032] Radio frequency (RF) repeaters act as signal boosters designed to extend network coverage / capacity and can be used in widespread deployments to supplement the coverage provided by conventional full-stack cells. Depending on the implementation, multiple RF repeaters forward RF signals without decoding. Examples of RF repeaters include network-controlled repeaters (NCRs) and reconfigurable smart surfaces (RIS) (sometimes called RIS repeaters). RISs can also sometimes be referred to as smart reflective surfaces (IRS).

[0033] Figure 3 An example NCR302 is shown. As illustrated, NCR302 can communicate with gNB202 and UE110. The NCR may include an NCR Mobile Terminal (NCR-MT) portion 304 (sometimes more simply referred to as NCR-MT) and an NCR Forwarding (NCR-Fwd) portion 306 (sometimes more simply referred to as NCR-Fwd). The NCR-MT can communicate with the gNB via a control link (C-link) to exchange control information, such as side control information for operating the NCR-MT and for controlling the NCR-Fwd. The NCR-MT can be considered a full-stack UE connected to the gNB, with additional functionality for exchanging side control information for the NCR-Fwd. The NCR-Fwd can communicate with the gNB via a backhaul link, and the NCR-Fwd can communicate with UE110 via an access link. The NCR-Fwd can perform uplink / downlink (UL / DL) RF signal amplification and forwarding between the gNB and the UE via the backhaul link and access link.

[0034] As indicated, the NCR302 may have the capability to receive and process side control information from the gNB202. This side control information includes control traffic received by the NCR-MT304 through a control link dedicated to controlling the NCR-Fwd306. The side control information may include, for example, beam management for the backhaul link, and beam configuration and indication for the access link. The access link can change dynamically, as access UE movement may require the use of different beams. Other examples of side control information include on / off information, time division duplex (TDD) UL / DL configuration, etc. The behavior of the NCR-Fwd can be controlled based on the side control information received from the gNB.

[0035] RIS (Radio Reflector Array) is currently being researched as a new technology to complement existing radio infrastructure in 6G / cellular systems. These surfaces include arrays of antenna elements that can be configured according to use cases. In this respect, RIS is a programmable antenna array solution for controlling the propagation of RF signals. Depending on the application, RIS can have the ability to modify the electrical and magnetic properties of the reflecting surface. RIS is designed to be a cost-effective alternative for deploying new gNB202s or acquiring new spectrum.

[0036] There are multiple use cases for RIS, including coverage enhancement and signaling multiplexing enhancement (capacity improvement). In this regard, RIS can be used to mitigate line-of-sight (LOS) congestion, thereby creating a virtual LOS. Additionally or alternatively, RIS can be used to enhance primary LOS MIMO channels with additional physical paths for capacity improvement.

[0037] Similar to the NCR302, the RIS is expected to be network-controlled by the gNB202, although other types of RIS can also exist, such as UE-controlled RIS, autonomous RIS, etc. In some examples, the RIS can have an architecture similar to the NCR. In this respect, Figure 4 An exemplary RIS402 is shown. As illustrated, the RIS402 can communicate with the gNB and UE110. The RIS may include a RIS-MT404 (sometimes more simply referred to as a control unit) and a RIS panel (sometimes referred to as the RIS-Fwd406) including an array of antenna elements. The RIS-MT can communicate with the gNB via a control link to exchange control information, similar to the NCR-MT304. And similar to the NCR-Fwd306, the RIS-Fwd can enhance UL / DL RF signals from / to the UE. In some implementations, the side control information used to control the NCR-Fwd can define the baseline function of the RIS in 6G.

[0038] 3GPP Release 18 provides three different configuration options for the NCR302, which can also be present in the RIS402. These configuration options include aperiodic activation, periodic activation, and semi-static activation. In aperiodic activation, the NCR-MT304 can be configured via RRC signaling, and the activation of the configuration can be provided via downlink control information (DCI) dynamically transmitted by the gNB202. In this configuration option, amplification and forwarding for a given time slot of the NCR beam can be dynamically controlled by the DCI transmitted by the gNB.

[0039] In periodic activation, the NCR-MT304 can be configured via RRC signaling and the configuration is immediately applied based on the periodicity provided in the configuration. Upon receiving the configuration, the NCR-MT can begin periodically boosting the RF signal based on the configuration. In semi-static activation, the NCR-MT can be configured via RRC signaling, and the activation of the configuration can be provided by a MAC control element (MAC-CE). When the NCR-MT receives the MAC-CE, it can apply the configuration based on the periodicity provided in the RRC configuration.

[0040] The network is now also beginning to support non-terrestrial networks (NTN). In NTN systems, RAN nodes (e.g., gNB202) or RAN node functionality can be deployed on satellites or other aerospace platforms in regenerative deployments (or architectures), or relayed by RAN nodes in transparent deployments. NTN can therefore provide communication coverage over very large areas that terrestrial radio access networks might not be able to reach. Such capabilities can be used for globally connected IoT devices, as well as providing personal communication in remote areas and disaster relief.

[0041] Figure 5 The implementation based on some examples is shown. Figure 2 Deployment 500 of NTN502 in PLMN102. As shown, the NTN may include an aerospace platform, such as satellite 504, which is connected to UE110 via serving link 506 (radio link) and to NTN gateway 508 via feeder link 510 (radio link). In regeneration deployments, the satellite (or other aerospace platform) may host gNB202 or a portion of a gNB, such as DU206. The NTN gateway may then connect to CN106; and in some examples involving CU-DU splitting, the NTN may host or connect to CU204, which in turn connects to the CN. In some examples, the NTN gateway and gNB may be co-located. The UE supporting the NTN may be a UE with Global Navigation Satellite System (GNSS) capability.

[0042] In various examples, an aerospace platform can be a spaceborne or airborne platform, an aircraft, etc. As indicated, an aerospace platform can be satellite 504. In other more specific examples, an aerospace platform can be a low Earth orbit (LEO) satellite, a medium Earth orbit (MEO) satellite, a geostationary orbit (GEO) satellite, etc. Similarly, in more specific examples, an aerospace platform can be an unmanned aerial vehicle system (UAS), such as a tethered UAS (TUA), a lighter-than-air UAS (LTA), a heavier-than-air UAS (HTA), a high-altitude platform (HAP), etc. Some example implementations of this disclosure can be described in the context of a satellite or UAS, but it should be understood that those example implementations are equally applicable to other aerospace platforms.

[0043] In a specific example of satellite 504, whose aerospace platform is NTN502, the satellite can generate a radio coverage beam with a corresponding coverage area 512 over a given service area defined by its field of view 514 and airborne antenna technology. The corresponding coverage area of ​​the radio beam is typically elliptical. The satellite's field of view can depend on the airborne antenna pattern and / or minimum elevation angle. A single radio beam can carry the signal of a cell, and several satellite radio beams can carry the signal of a single cell or multiple cells.

[0044] As currently specified, NTN502 can be deployed in several different ways. In one deployment, the NTN cell served by satellite 504 (or other aerospace platform) is deployed as a fixed Earth cell that always serves a geographic area (e.g., in the case of a GSO satellite). In another deployment, the satellite-served NTN cell is deployed as a quasi-fixed Earth cell that serves different geographic areas for a limited time period. And in yet another deployment, the satellite-served NTN cell is deployed as a mobile Earth cell that serves a coverage area that slides across the Earth's surface.

[0045] In quasi-Earth fixed cell and Earth mobile cell deployments, UE110 in a geographic area can switch from one satellite 504 to another when the satellite and the NTN cell served by the satellite follow a specific trajectory. Figure 6 An example of satellite handover in NTN502 is illustrated in a regeneration deployment, where a first satellite host provides the source gNB504A for a first NTN cell, and a second satellite host provides the target gNB504B for a second NTN cell. In some examples, the NTN cell is a quasi-Earth fixed cell serving geographic area 604. In this respect, at least for a limited period of time during which the NTN cell serves the geographic area, the first NTN cell and the second NTN cell can be the same cell 602 serving that geographic area. Until the satellite handover, UE110 can be stationary and served by the first NTN cell of the first satellite. When the first satellite moves away from the UE and the second satellite approaches the UE, the UE can handover from the source gNB to the target gNB.

[0046] It has been recognized that NTN502 may have drawbacks, especially for indoor environments, due to the fact that satellite 504 may be located 1000 km or more above the Earth's surface, and the geographic radius of the provided NTN cell coverage area is greater than 10 km, resulting in significant path loss due to distance. Adding RF repeaters (such as NCR302 or RIS402) to the deployment of 500 can help mitigate this path loss drawback and improve channel conditions for non-LOS UE110 indoors. Therefore, the combination of NTN and RF repeaters can provide a viable option for comprehensive connectivity.

[0047] Despite the promising combination of NTN502 and RF repeaters, one problem with RF repeaters involves the process of selecting the beam for the RF repeater used in UE110, which can be an expensive process. This problem can be even more pronounced for NTN cells covered by satellite 504 in the NTN. Figure 6As shown, for example, when the target gNB504B (satellite) replaces the source gNB504A (satellite) to serve geographic area 604 for a given next duration, the target gNB may need to perform a large number of measurements to enable the use of RIS402 for UEs coming from / going to the geographic area. That is, the target gNB may need to perform a large number of measurements to identify UEs associated with RIS and then select RIS beams for these UEs.

[0048] Therefore, a challenge with the NTN502 and RIS402 combination might be how to efficiently perform RIS beam selection and UE selection, which the UE would benefit from in a quasi-terrestrial fixed NTN deployment using satellite 504 (e.g., a LEO constellation). It's worth noting that similar challenges can also be applied to other RF repeaters, such as the NCR302. Similarly, similar challenges can be applied to earth-mobile NTN deployments, and in situations where the RIS, NCR, or other RF repeaters move with the UE110 (e.g., on a train), such as in terrestrial networks.

[0049] In light of the foregoing, the example implementations of this disclosure provide a solution to the aforementioned problems of efficiently performing RIS beam selection and UE selection in a scenario where one gNB504A (satellite) is replaced by another gNB504B (satellite) to serve cell 602 for a given next duration. According to some example implementations, when one gNB is replaced by another gNB (target gNB), a handover procedure can be performed for (multiple) UEs110 and (multiple) RIS-MT404 connected to one gNB (source gNB). The example implementations can be applied to several different deployments, including deployments where the RIS402 and (multiple) UEs are unaware of each other. In these deployments, the RIS can be referred to as a UE-transparent RIS, and (multiple) UEs can be referred to as (multiple) RIS-transparent UEs. In other deployments, the RIS (RIS-MT) can utilize the RIS to become aware of the UEs, and the RIS can sometimes be referred to as a UE-aware RIS. And in other deployments, (multiple) UEs can be aware that they are utilizing the RIS, and these UEs can sometimes be referred to as RIS-aware UEs.

[0050] In some example implementations, the source gNB504A can send a handover request to the target gNB504B for (multiple) UE110 / RIS-MT404. The handover request may include information to assist the target gNB in ​​selecting one or more UE110s to utilize the RIS402 deployed in cell 602, and selecting one or more beams of the RIS for each UE. The handover request, including this assisting information, can be sent for handover of each UE (if the UE is using the RIS in the source gNB504A) or for handover of the RIS-MT404. The assisting information may include, for example, the UE ID (e.g., Cell Radio Network Temporary Identifier (C-RNTI), Xn Application Protocol (XnAP) UE ID) used by each UE. In some examples, the (multiple) RIS beams may be beam pairs of the RIS and the gNB. In some examples, the RIS (RIS-Fwd406) may provide a beam grid, and each beam may be assigned an ID. Similarly, in the example where the NTN502 is assisted by the NCR302, the NCR can provide a beam grid, and each beam can be assigned an ID.

[0051] In some examples, the source gNB504A (and the target gNB504B) may attempt to optimize a beam pair including the RIS beam and the gNB beam (this beam pair is sometimes referred to as the RIS-gNB beam pair) for radio transmission. Then, in some examples, auxiliary information may indicate one or more RIS-gNB beam pairs. This indication of (multiple) RIS-gNB beam pairs may be useful when the source and target gNB (satellite) beam constellations are the same, although this indication can also be provided in other cases where the beam constellations are different.

[0052] Based on the trajectory of the source gNB504A, the (multiple) RIS beams (or RIS-gNB beam pairs) may differ at different times when the source gNB serves cell 602. Then, in some examples, auxiliary information may include the set of beams used at different times; and in some other examples, the set of beams used at different times may be provided along with the trajectory information of the source gNB. This trajectory information may include, for example, velocity, coordinates, the angle between RIS402 and the source gNB, etc. Based on the trajectory, the use of the RIS (and RIS beams) may differ for each UE at different times. In some examples, the start / stop time of RIS use may also be provided for each UE. This time may indicate the (multiple) actual time windows (possibly relative to the time the cell is served by the source gNB) of the RIS.

[0053] In some examples, to assist the target gNB504B in deciding whether to update the measurements of(multiple) UE110, the auxiliary information may include information about when the last RIS beam selection was performed for(multiple) UE110. Additionally or alternatively, in some examples, to assist the target gNB in ​​deciding to use RIS402 for other(multiple) UEs, the auxiliary information may include information about(multiple) UEs that do not utilize the RIS in the source gNB504A, such as measurements from the RIS beam scan and when these measurements were performed.

[0054] In some examples of RIS-MT404 involving UE-aware RIS402, the RIS-MT itself can report auxiliary information about (multiple) UEs (to the target gNB504B) that the UE(s)(s) are using RIS-Fwd406 in the source gNB504A during handover. In some of these examples, the target gNB504B can request auxiliary information from the RIS-MT, such as in a handover command or after handover is completed using the UE information retrieval process.

[0055] In some examples involving (multiple) RIS-aware UEs 110, the UE itself can report (to the target gNB 504B) auxiliary information regarding the UE's use of RIS 402 (or more specifically RIS-Fwd 406) when a handover is performed or requested from the target gNB. In some of these examples, the UE can also report to the target gNB whether new measurements (e.g., channel measurements) would be beneficial (based on the UE's own movement), such as whether the UE has moved significantly compared to the last time RIS / beam selection was performed. In some examples, the target gNB can also assess whether the beam provided by the source gNB is optimal for the UE (and the target gNB can also test whether RIS would benefit other UEs).

[0056] Typically, when the RIS-MT404 handover precedes the handover of (multiple) UEs 110 and auxiliary information is provided to the target gNB 504B during the RIS-MT handover, the target gNB can utilize RIS402 to maintain the UE's UE ID in memory until the UE is handed over to the target gNB. When the handover of (multiple) UEs precedes the RIS-MT handover and auxiliary information is provided to the target gNB during the UE handover, the target gNB can maintain the RIS usage of each UE in memory. It is worth noting that, depending on whether RIS-MT or which of the (multiple) UEs is handed over before the other, in some examples, the auxiliary information can be sent by the source gNB 504A in different messages.

[0057] Figure 7A , Figure 7B and Figure 7C Signaling diagram 700 illustrates one or more processes in a deployment including a UE-transparent RIS402 and(multiple) RIS-transparent UE110, implemented according to some examples. As shown, a connection can be established between the RIS (RIS-MT404) and the source gNB504A at step 701. The source gNB can configure the RIS402 and(multiple) UEs to perform beam scanning against the RIS at steps 702 and 703, and configure the UEs to perform beam measurements of the RIS beam. The source gNB can perform reference signal transmission, such as Channel State Information Reference Signal (CSI-RS) transmission, at step 704, which can be forwarded via the RIS. The transmission can overlap with different RIS beams, allowing(multiple) UEs to perform RIS beam measurements. The(multiple) UEs can report the measurements to the source gNB at step 705.

[0058] The source gNB504A can, at step 706, determine which UE(s)110 should be served by RIS402 and which RIS beams are used to serve the UE(s) based on measurements reported by the UE(s). The source gNB can, at step 707, record the current time and location of the source gNB (satellite) when UE and RIS beam selection is performed, or when the measurement making the selection is executed. This location may include, for example, the source gNB's coordinates, velocity, and / or trajectory information. In some examples, this location may also include the angle between RIS-Fwd406 (line-of-sight direction) and the source gNB.

[0059] As shown in step 708, RIS402 can be used to serve (multiple) UEs 110 for radio transmissions from source gNB 504A. Due to the movement of the source gNB (satellite), the source gNB can decide at step 709 to hand over (multiple) UEs and RIS402 (RIS-MT404) to the target gNB 504B. Then, the source gNB can subsequently initiate a handover of (multiple) UEs and RIS from the source gNB to the target gNB.

[0060] In the first option, the source gNB504A may send a handover request for the UE(s) related to the handover of UE(s)110 to the target gNB504B in step 710, and the request may include auxiliary information to assist the target gNB in ​​making the following determinations: using RIS402 to serve the UE, and the RIS(s) beams(s) used to serve the UE. In some examples, the auxiliary information may identify the RIS (RIS ID) and the RIS beams (or the RIS-gNB beam pairs(s) used to serve the UE). Additionally or alternatively, for example, the auxiliary information may identify / include (e.g., by adding time / location information) (the RIS beams(s) used to serve the UE at different times). In some of these examples, the auxiliary information may include trajectory information of the source gNB at different times, which may be expressed in the same or similar manner as described above in step 707.

[0061] In some examples, the auxiliary information may additionally or alternatively include the start time / location and / or stop time / location of using RIS402 to serve UE110. In some of these examples, the auxiliary information may include the start time / location or stop time / location used by the RIS beam of the RIS. Furthermore, in some examples, the auxiliary information may additionally or alternatively include information about the time / location of when the latest RIS / beam selection was made for the UE, or the time / location of when the latest(s) measurement(s) that made the selection were performed.

[0062] The target gNB 504B can receive a handover request, and at step 711, the target gNB can make a determination based on auxiliary information regarding: using RIS 402 to serve UE 110, and the RIS(pairs) beams(s) used to serve the UE. In this regard, the target gNB can determine whether / when to maintain RIS (and the beam(pairs) used for the UE). In the example where the UE is handed over before RIS, the target gNB can remember the auxiliary information and determine whether / when to maintain RIS (and the beam(pairs) used when RIS is handed over to the target gNB).

[0063] The target gNB504B can create a measurement and reference signal configuration at step 712 based on the determination made at step 711. The source gNB504A and the target gNB can send a handover command including the reference signal configuration to the UE110 at step 713. The handover from the UE to the target gNB can then be completed at step 714.

[0064] In the second option, the source gNB504A may send a handover request for the RIS (RIS-MT404) related to the handover of the RIS402 to the target gNB504B at step 715, and this request may include auxiliary information to assist the target gNB in ​​making the following determinations: using the RIS402 to serve the UE, and the RIS beams (or multiple RIS beams) used to serve (multiple) UEs. In some examples, the auxiliary information may identify (multiple) UEs ((multiple) UE IDs) and (multiple) RIS beams (or (multiple) RIS-gNB beam pairs) used to serve each UE at different times (e.g., by adding time / location information). Additionally or alternatively, for example, the auxiliary information may identify / include (multiple) RIS beams (or (multiple) RIS-gNB beam pairs) used to serve each UE at different times (e.g., by adding time / location information). In some of these examples, the auxiliary information may include trajectory information of the source gNB at different times, which may be expressed in the same or similar manner as described above in step 707.

[0065] In some examples, the auxiliary information may additionally or alternatively include the start time / location and / or stop time / location of using RIS402 to serve each UE110. In some of these examples, the auxiliary information may include the start time / location or stop time / location used by the RIS beam of the RIS. Furthermore, in some examples, the auxiliary information may additionally or alternatively include information about the time / location at which the latest RIS / beam selection was made, or information about the time / location at which the latest measurement(s) for making the selection was performed. And in some examples, the auxiliary information may instruct (multiple) other UE(s) not served by the RIS to assist target gNB504B in determining whether to select any (multiple) other UE(s) to be served by the RIS beam(s) of the RIS(s).

[0066] The target gNB504B can receive a handover request, and at step 716, based on auxiliary information, the target gNB can make the following determinations: using RIS402 to serve UE110, and the RIS beam(s) used to serve(multiple) UEs(s). In this regard, the target gNB can determine whether / when to maintain the RIS (and the beam(pair) used for the UE). In the example where the RIS (RIS-MT404) was handed over before the UE, the target gNB can remember the auxiliary information and determine whether / when to maintain the RIS (and the beam(pair) used when the UE was handed over to the target gNB).

[0067] The target gNB504B can create a measurement and reference signal configuration at step 717 based on the determination made at step 716. The source gNB504A can receive the reference signal configuration at step 718 and send a switching command (RIS-MT404) including the reference signal configuration to RIS402. The switching from RIS402 to the target gNB can then be completed at step 719.

[0068] As shown in step 720, during the handover between (multiple) UE110 and RIS402 (RIS-MT404), RIS can be used to serve (multiple) UEs for radio transmissions from the target gNB504B, which can be based on auxiliary information.

[0069] In some examples involving CU-DU splitting of source gNB504A, source CU204 or DU206 of source gNB504A can perform step 707. In some examples where step 707 is performed by source DU, source DU can notify source CU of the current time and location of source gNB (satellite) when selecting UE and RIS beams, or when the measurement for selection is performed. Source DU can report information immediately after it is recorded or upon request by source CU. In examples involving CU-DU splitting of target gNB504B, auxiliary information in the handover request can be received by target CU and sent by target CU to target DU, which can perform steps 711, 712 (and steps 716, 717).

[0070] Figure 8A , Figure 8B and Figure 8C Signaling diagram 800 illustrates one or more processes in a UE-aware RIS402 deployment implemented according to some examples. As shown, a connection can be established between the RIS (RIS-MT404) and the source gNB504A at step 801. The source gNB can configure the RIS402 and(multiple) UEs110 to perform beam scanning against the RIS at steps 802 and 803, and configure the UEs to perform beam measurements of the RIS. The source gNB can perform a reference signal transmission, such as a CSI-RS transmission, that can be forwarded via the RIS at step 804. The transmission can overlap with different RIS beams, allowing(multiple) UEs to perform RIS beam measurements.

[0071] RIS402 can learn in step 805 which UE(s)110 is being served by RIS. In some examples, RIS can learn which UE(s) themselves are using CSI-RS transmission, such as through autodetection. In some other examples, the source gNB504A can inform RIS of the UE(s) through signaling messages, for example. Multiple UE(s) can report measurements to the source gNB in ​​step 806.

[0072] When measurements reported by (multiple) UEs 110 are performed, RIS 402 may record the current time and location of the source gNB 504A (satellite) in step 807. This recording may, in some examples, be in response to a command from the source gNB. The location may include, for example, the coordinates, velocity, and / or trajectory information of the source gNB. In some examples, the location may also include the angle between RIS-Fwd406 (line of sight) and the source gNB. The source gNB may, at step 808, determine which UE(s) are served by RIS 402 and which RIS beams are used to serve (multiple) UEs based on the measurements reported by (multiple) UEs. RIS may again learn which UEs are being served by RIS in steps 809 and 810, and record the current time and location of the source gNB when making a selection of UEs and RIS beams.

[0073] As shown in step 811, RIS402 can be used to serve (multiple) UEs 110 for radio transmissions from source gNB 504A. Due to the movement of the source gNB (satellite), the source gNB can decide at step 812 to hand over (multiple) UEs and RIS (RIS-MT404) to the target gNB 504B. Then, the source gNB can subsequently initiate a handover of (multiple) UEs and RIS from the source gNB to the target gNB.

[0074] In the first option, during the handover of RIS402 (RIS-MT404), the source gNB504A may send a RIS-MT handover request to the target gNB504B at step 813. The source gNB may send a handover command to RIS402 (RIS-MT404) at step 814, and the handover command may optionally include a request for auxiliary information from the target gNB. Then, the RIS may send a handover completion (e.g., RRC reconfiguration complete) message to the target gNB at step 815, and the handover completion message may include auxiliary information to assist the target gNB in ​​making determinations regarding: using the RIS to serve(multiple) UEs, and the RIS beam(s) used by the RIS to serve(multiple) UEs.

[0075] In some examples, auxiliary information may identify (multiple) UE110 (multiple) UE IDs and (multiple) RIS beams (or (multiple) RIS-gNB beam pairs) for serving each of the (multiple) UEs. Additionally or alternatively, for example, auxiliary information may identify / include (multiple) RIS beams (or (multiple) RIS-gNB beam pairs) for serving each UE at different times (e.g., by adding time / location information). In some of these examples, auxiliary information may include trajectory information of the source gNB at different times, which may be expressed in the same or similar manner as described above.

[0076] In some examples, the auxiliary information may additionally or alternatively include the start time / location and / or stop time / location of using the RIS402 to serve each UE110. In some of these examples, the auxiliary information may include the start time / location or stop time / location used by the RIS beam. Furthermore, in some examples, the auxiliary information may additionally or alternatively include information about the time / location at which the latest RIS / beam selection was made, or information about the time / location at which the latest measurement for making that selection was performed.

[0077] The target gNB504B can receive a handover completion message, and at step 816, based on auxiliary information, the target gNB can determine whether to use RIS402 to serve (multiple) UEs 110, and the RIS beam for serving (multiple) UEs. In this regard, the target gNB can determine whether / when to maintain the RIS (and beam pair) for (multiple) UEs. In the example where a UE is handed over before the RIS, the target gNB can remember the auxiliary information and determine whether / when to maintain the RIS (and beam pair) when the RIS is handed over.

[0078] In the second option, the source gNB504A can send a switch request for the RIS402 (RIS-MT404) to the target gNB504B in step 817. The source gNB can send a switch command to the RIS (RIS-MT) in step 818. The RIS can retain its recorded information in the memory to be reported to the target gNB (e.g., for 48 hours) at step 819. The switch from the RIS to the target gNB can be completed in step 820.

[0079] Following the handover of RIS402 (RIS-MT404), the target gNB504B may send a UE information request to the RIS at step 821. This UE information request may include a request for auxiliary information to assist the UE and RIS beam selection. The RIS may then send a UE information response, including auxiliary information, to the target gNB at step 822 to assist the target gNB in ​​making the following determinations: using the RIS to serve(multiple) UEs, and the RIS beam(s) used to serve(multiple) UEs. In some other examples, the RIS may report auxiliary information to the target gNB without a request for such information from the target gNB. The auxiliary information may include the same or similar information described above in step 815.

[0080] The target gNB504B can receive UE information responses, and at step 823, based on auxiliary information, the target gNB can determine whether to use RIS402 to serve (multiple) UEs 110, and the RIS beam used to serve (multiple) UEs. In this regard, the target gNB can determine whether / when to maintain the RIS (and beam pair) for (multiple) UEs. In the example where the UE is switched before the RIS, the target gNB can remember the auxiliary information and determine whether / when to maintain the RIS (and beam pair) when the RIS is switched.

[0081] As shown in step 824, during the switching of beam selection between (multiple) UE110 and RIS402 (RIS-MT404) and between UE and RIS, the RIS can be used to serve (multiple) UEs for radio transmissions from the target gNB504B, which can be based on auxiliary information.

[0082] In some examples involving CU-DU splitting target gNB504B, target DU206 may perform steps 816 and 823 after receiving auxiliary information from RIS402 via target CU204.

[0083] Figure 9A , Figure 9B and Figure 9CSignaling diagram 900 illustrates one or more processes in a deployment including multiple RIS-aware UEs 110, implemented according to some examples. As shown, a connection can be established between the RIS (RIS-MT404) and the source gNB 504A at step 901. The source gNB can configure the RIS 402 and the multiple UEs 110 to have a configuration for the RIS to perform beam scanning in steps 902 and 903, and configure the UE to perform beam measurements for the RIS. At step 904, the UE can be aware that it is being served by the RIS. In some examples, the UE can be aware that it is being served by the RIS itself, such as through automatic detection. In some other examples, the source gNB 504A can inform the UE of the RIS, for example, through a signaling message.

[0084] The source gNB504A can perform a reference signal transmission, such as a CSI-RS transmission, that can be forwarded via RIS402 at step 905. The transmission can overlap with different RIS beams, allowing (multiple) UEs to perform RIS beam measurements. (Multiple) UEs can report the measurements to the source gNB at step 906.

[0085] When a measurement reported by the UE is performed, the UE110 may record the current time and location of the source gNB504A (satellite) in step 907. This recording may, in some examples, be in response to a command from the source gNB. The location may include, for example, the coordinates, velocity, and / or trajectory information of the source gNB. In some examples, the UE may record the time and location when performing a new measurement using a reference signal with RIS402. In this regard, in some examples, the UE may know whether a particular CSI-RS signal is enhanced by RIS by having an explicit configuration in the CSI RS itself. In a more specific example, the UE may record the time and location of the source gNB when the measurement report was last sent using RIS, and the UE may maintain a log in memory for each RIS.

[0086] The source gNB504A can determine, at step 908, which UE(s)110 should be served by the RIS402, and which RIS beam(s) should be used to serve the UE(s), based on measurements reported by the UE(s). The UE can again know in steps 909 and 910 that it is being served by the RIS, and record the current time and location of the source gNB when making the UE and RIS beam selection.

[0087] In some more specific examples, UE110 can be made aware that it is being served by RIS402 by providing an explicit indication in the downlink control information (DCI) that schedules data transmission from source gNB504A. This DCI can explicitly indicate which RIS is being used. The UE can record the time and location of the source gNB upon receiving the DCI, or record the time and location when sending the latest measurement report. Some other examples can use a quasi-co-location (QCL) framework. In these examples, the UE can be given information about the quasi-co-location of the scheduled data with the reference signal transmitted via the RIS (as described above). The UE can then implicitly understand that the RIS has been selected for use and record the time and location of the source gNB (or the time / location when sending the latest reference signal measurement).

[0088] As shown in step 911, RIS402 can be used to serve (multiple) UEs 110 for radio transmissions from source gNB 504A. Due to the movement of the source gNB (satellite), the source gNB can decide at step 912 to hand over (multiple) UEs and RIS (RIS-MT404) to the target gNB 504B. Then, the source gNB can subsequently initiate a handover of (multiple) UEs and RIS from the source gNB to the target gNB.

[0089] In the first option, during the handover of UE110, the source gNB504A may send a handover request for the UE to the target gNB504B in step 913. The source gNB may send a handover command to the UE at step 914, and the handover command may optionally include a request for auxiliary information from the target gNB. Then, the UE may send a handover complete (e.g., RRC reconfiguration complete) message to the target gNB at step 915, and the handover complete message may include auxiliary information to assist the target gNB in ​​making the following determinations: using RIS402 to serve the UE, and the RIS beam(s) used to serve(multiple) UEs.

[0090] In some examples, auxiliary information may identify the RIS402 (RIS ID) and the RIS beams (or RIS-gNB beam pairs) used to serve (multiple) UEs. Additionally or alternatively, for example, auxiliary information may identify / include the RIS beams (or RIS-gNB beam pairs) used to serve (multiple) UEs at different times (e.g., by adding time / location information). In some of these examples, auxiliary information may include trajectory information of the source gNB at different times, which may be expressed in the same or similar manner as described above.

[0091] In some examples, the auxiliary information may additionally or alternatively include the start time / location and / or stop time / location of using RIS402 to serve UE110. In some of these examples, the auxiliary information may include the start time / location or stop time / location of the RIS beam usage. Furthermore, in some examples, the auxiliary information may additionally or alternatively include information about the time / location of the latest RIS / beam selection, or the time / location of the latest measurement performed to make that selection.

[0092] The target gNB504B can receive the handover completion message, and at step 916, based on auxiliary information, the target gNB can determine whether to use RIS402 to serve UE110, and the RIS(pairs) beam(s) used to serve the UE. In this regard, the target gNB can determine whether / when to maintain the RIS(and beam(pairs)) for the UE. In the example where the UE is handed over before the RIS, the target gNB can remember the auxiliary information and determine whether / when to maintain the RIS(and beam(pairs)) when the RIS is handed over.

[0093] In the second option, the source gNB 504A can send a handover request for UE 110 to the target gNB 504B in step 917. The source gNB can send a handover command to the UE in step 918. The UE can retain the information it has recorded in the memory to be reported to the target gNB (e.g., for 48 hours) in step 919. The handover from the UE to the target gNB can be completed in step 920.

[0094] After the handover of UE110, the target gNB504B may send a UE information request to the UE in step 921, and the UE information request may include a request for auxiliary information to assist the UE and RIS beam selection. The UE may send a UE information response including auxiliary information to the target gNB in ​​step 922 to assist the target gNB in ​​making the following determinations: using RIS402 to serve the UE, and the RIS(s) beam(s) used to serve the UE. In some other examples, the UE may report auxiliary information to the target gNB without a request for auxiliary information from the target gNB. The auxiliary information may include the same or similar information described above in step 915.

[0095] The target gNB504B can receive UE information responses, and at step 923, based on auxiliary information, the target gNB can determine whether to use RIS402 to serve UE110, and the RIS(pairs) beams(s) used to serve the UE. In this regard, the target gNB can determine whether / when to maintain the RIS(and beam(pairs)) for the UE. In the example where the UE is switched before the RIS, the target gNB can remember the auxiliary information and determine whether / when to maintain the RIS(and beam(pairs)) when the RIS is switched.

[0096] As shown in step 924, during the switching of beam selection between (multiple) UE110 and RIS402 (RIS-MT404) and between UE and RIS, the RIS can be used to serve (multiple) UEs for radio transmissions from the target gNB504B, which can be based on auxiliary information.

[0097] In some examples involving CU-DU splitting target gNB504B, target DU206 may perform steps 916 and 923 after receiving auxiliary information from UE110 via target CU204.

[0098] The processes shown in signaling diagrams 700, 800, and 900 focus on downlink (DL) transmissions from source gNB504A (satellite) to (multiple) UEs110 via RIS402, and then DL transmissions from target gNB504B (satellite) to (multiple) UEs via RIS. It should be understood that (multiple) processes can be applied equally to uplink (UL) transmissions from (multiple) UEs to the source gNB (and subsequently the target gNB) via RIS. In some examples, further information regarding UL and DL may be provided separately to the target gNB.

[0099] Depending on the different beam constellations at gNB504A and 504B (satellites), the optimal RIS-gNB beam pair may differ for different satellites. Some example implementations of this disclosure can be applied when the satellite beam constellations are the same (and then beam pair information from source to target is given) or when the satellite beam constellations are different.

[0100] In some examples where the beam constellations differ, RIS beam information can be provided from the source gNB to the target gNB. In these examples, the RIS beam selection may be suboptimal for the target gNB due to the different beam constellations, but given the sufficiently large satellite beams, this information may actually be redundant. Furthermore, in such deployments, the target gNB can start with the indicated RIS beam and, if necessary, further optimize the RIS beam by performing measurements.

[0101] As described above, although primarily within the context of quasi-terrestrial fixed NTN deployments on satellites 504 (e.g., the LEO constellation), some example implementations are equally applicable to terrestrial mobile NTN deployments, as well as in situations where a RIS, NCR, or other RF repeater moves with the UE 110 (e.g., on a train), such as in terrestrial networks. In such cases, in deployments including a UE-transparent RIS 402 and (multiple) RIS-transparent UE 110s, the source gNB 504A may need to know that the RIS is mobile and that (multiple) UEs served by the RIS are moving with the RIS. This can trigger the source gNB to include further auxiliary information when switching the RIS or the corresponding (multiple) UEs to the target gNB 504B. In deployments including a UE-aware RIS, in some examples, the RIS can know that the RIS is mobile and that (multiple) UEs served by the RIS are moving with the RIS. And in deployments including a RIS-aware UE, in some examples, the UE can be made aware that it is mobile and moving with the RIS serving it.

[0102] Figure 10 This is a flowchart illustrating various steps in method 1000 implemented according to various examples. The method includes receiving radio access service from a source node, wherein at least one radio frequency (RF) repeater is used to serve one or more user equipments (UEs) for radio transmissions from or to the source node, as shown in box 1002. The method includes performing a handover of one or more UEs or at least one RF repeater from the source node to a target node, as shown in box 1004. The method further includes sending auxiliary information relating to the handover to the target node, the auxiliary information assisting the target node in making determinations regarding: using the at least one RF repeater to serve the one or more UEs, and at least one beam of the at least one RF repeater for serving each of the at least one UE, as shown in box 1006.

[0103] In some examples, the source node and the target node are the first aerospace platform in a non-terrestrial network (NTN), and at least one RF repeater includes at least one of a network-controlled repeater (NCR) or a reconfigurable smart surface (RIS).

[0104] In some examples, the method is performed by at least one RF repeater, and the handover is a switch of at least one RF repeater from the source node to the target node.

[0105] In some examples, the auxiliary information identifies each of one or more UEs, and one or more beams of at least one RF repeater for serving each UE.

[0106] In some examples, one or more beams of at least one RF repeater are indicated by one or more beam pairs, and each beam pair in the one or more beam pairs includes the beam of at least one RF repeater and the beam of the source node.

[0107] In some examples, the auxiliary information also identifies or includes at least one of the following: one or more beams of at least one RF repeater for serving each UE at different times; trajectory information of the source node at different times; at least one of the start time or stop time of using at least one RF repeater to serve each UE; or at least one of the time or location of the source node when the source node selects one or more beams of at least one RF repeater for serving each UE, or when one or more measurements of the selection are performed.

[0108] In some examples, the method is executed by a UE in one or more UEs, and the handover is a handover of the UE from the source node to the target node.

[0109] In some examples, auxiliary information identifies at least one RF repeater and one or more beams of at least one RF repeater used to serve the UE.

[0110] In some examples, the auxiliary information also identifies or includes at least one of the following: one or more beams of at least one RF repeater for serving the UE at different times; trajectory information of the source node at different times; at least one of the start time or stop time of using at least one RF repeater to serve the UE; or at least one of the time or location of the source node when the source node selects one or more beams of at least one RF repeater for serving the UE, or when one or more measurements of the selection are performed.

[0111] In some examples, during the handover of one or more UEs or at least one RF repeater, auxiliary information is sent at box 1006 in a handover completion message, or after the handover of one or more UEs or at least one RF repeater is completed, in a response to an information request.

[0112] In some examples, performing a handover in box 1004 includes sending a handover completion message, which includes auxiliary information, to the target node.

[0113] In some examples, method 1000 also includes receiving an information request from the target node and sending a response to the information request to the target node, the response including auxiliary information.

[0114] Figure 11A and 11BThis is a flowchart illustrating the various steps of method 1100 implemented according to various examples. The method includes providing radio access service by a source node, wherein at least one radio frequency (RF) repeater is used to serve one or more user equipments (UEs) for radio transmissions from or to the source node, such as... Figure 11A As shown in box 1102, the method includes initiating a handover of one or more UEs and at least one RF repeater from a source node to a target node, as shown in box 1104. The method also includes sending auxiliary information to the target node relating to the handover of the one or more UEs or the at least one RF repeater, the auxiliary information being used to assist the target node in making a determination regarding the use of the at least one RF repeater to serve the one or more UEs, and at least one beam of the at least one RF repeater for serving the at least one UE, as shown in box 1106.

[0115] In some examples, the source node and the target node are the first aerospace platform in a non-terrestrial network (NTN), and at least one RF repeater includes at least one of a network-controlled repeater (NCR) or a reconfigurable smart surface (RIS).

[0116] In some examples, the auxiliary information at box 1106 is sent regarding the handover of one or more UEs, and in some of these examples, the auxiliary information identifies at least one RF repeater and one or more beams of the at least one RF repeater for serving the UE.

[0117] In some examples, one or more beams of at least one RF repeater are indicated by one or more beam pairs, and each beam pair in the one or more beam pairs includes the beam of at least one RF repeater and the beam of the source node.

[0118] In some examples, the auxiliary information also identifies or includes at least one of the following: one or more beams of at least one RF repeater used to serve the UE at different times; trajectory information for source node instances at different times; or at least one of the start time or stop time of using at least one RF repeater to serve the UE.

[0119] In some examples, auxiliary information is transmitted at box 1106 regarding the handover of at least one RF repeater. In some of these examples, the auxiliary information identifies each of one or more UEs and one or more beams of at least one RF repeater for serving each UE.

[0120] In some examples, one or more beams of at least one RF repeater are indicated by one or more beam pairs, and each beam pair in the one or more beam pairs includes the beam of at least one RF repeater and the beam of the source node.

[0121] In some examples, the auxiliary information also identifies or includes at least one of the following: one or more beams of at least one RF repeater for serving each UE at different times; trajectory information of the source node at different times; or at least one of the start time or stop time of using at least one RF repeater to serve each UE.

[0122] In some examples, method 1100 also includes selecting one or more beams for at least one RF repeater serving each UE based on one or more measurements performed on one or more UEs, such as Figure 11B As shown in box 1108. In some of these examples, the method further includes recording at least one of the time or location of the source node when the selection is made, as shown in box 1110. Also in some of these examples, auxiliary information includes at least one of the time or location of the source node when the selection is made, or when one or more measurements are performed.

[0123] In some examples, the auxiliary information indicates one or more other UEs not served by at least one RF repeater to assist the target node in making a determination regarding whether to select any of the other one or more UEs to be served by at least one beam of at least one RF repeater.

[0124] Figure 12 This is a flowchart illustrating various steps in method 1200 implemented according to various examples. The method includes performing a handover from a source node to a target node for one or more user equipments (UEs) and at least one radio frequency (RF) repeater for serving the one or more UEs, as shown in box 1202. The method includes receiving, at the target node, auxiliary information relating to the handover of the one or more UEs or the at least one RF repeater, as shown in box 1204. The method includes, based on the auxiliary information, making a determination in box 1206 regarding the use of the at least one RF repeater to serve the one or more UEs, and at least one beam of the at least one RF repeater for serving each of the at least one UE. Based on this determination, the method includes providing radio access service from the target node to the one or more UEs, wherein the at least one RF repeater is used to serve at least one of the one or more UEs for radio transmissions from or to the target node, as shown in box 1208.

[0125] In some examples, the source node and the target node are the first aerospace platform in a non-terrestrial network (NTN), and at least one RF repeater includes at least one of a network-controlled repeater (NCR) or a reconfigurable smart surface (RIS).

[0126] In some examples, auxiliary information is received at box 1204 from the source node or at least one RF repeater, and the auxiliary information identifies each of one or more UEs and one or more beams of at least one RF repeater used to serve each UE.

[0127] In some examples, one or more beams of at least one RF repeater are indicated by one or more beam pairs, and each beam pair in the one or more beam pairs includes the beam of at least one RF repeater and the beam of the source node.

[0128] In some examples, the auxiliary information also identifies or includes at least one of the following: one or more beams of at least one RF repeater for serving each UE at different times; trajectory information of the source node at different times; at least one of the start time or stop time of using at least one RF repeater to serve each UE; or at least one of the time or location of the source node when the source node selects one or more beams of at least one RF repeater for serving each UE, or when one or more measurements of the selection are performed.

[0129] In some examples, auxiliary information for each UE is received from the UE at box 1204, and the auxiliary information identifies at least one RF repeater and one or more beams of the at least one RF repeater for serving the UE.

[0130] In some examples, the auxiliary information also identifies or includes at least one of the following: one or more beams of at least one RF repeater for serving the UE at different times; trajectory information of the source node at different times; at least one of the start time or stop time of using at least one RF repeater to serve the UE; or at least one of the time or location of the source node when the source node selects one or more beams of at least one RF repeater for serving the UE, or when one or more measurements of the selection are performed.

[0131] In some examples, auxiliary information is received from the source node at box 1204, and the auxiliary information indicates one or more other UEs not served by at least one RF repeater. In some of these examples, a further determination is made regarding whether to select any one of the other one or more UEs to be served by at least one beam of the at least one RF repeater.

[0132] In some examples, auxiliary information at box 1204 regarding the handover of one or more UEs or at least one RF repeater is received from the source node.

[0133] In some examples, auxiliary information is received from at least one RF repeater during the handover of at least one RF repeater, in a handover completion message at box 1204, or in a response to an information request after the handover of at least one RF repeater is completed.

[0134] In some examples, performing a handover in box 1202 includes receiving a handover completion message that includes auxiliary information from at least one RF repeater.

[0135] In some examples, method 1200 further includes sending an information request to at least one RF repeater. In some of these examples, the method further includes receiving a response to the information request from at least one RF repeater, the response including auxiliary information.

[0136] In some examples, at box 1204, auxiliary information for each of one or more UEs is received from the UE during the handover of the UE, in a handover completion message, or in a response to an information request after the handover of the UE is completed.

[0137] In some examples, performing a handover at box 1202 includes receiving a handover completion message from the UE, which includes auxiliary information for the UE.

[0138] In some examples, method 1200 also includes sending an information request to the UE. In some of these examples, the method also includes receiving a response to the information request from the UE, the response including auxiliary information for the UE.

[0139] According to the example implementations of this disclosure, the telecommunications system 100 or PLMN 102 and its components (such as UE 110, CN 106, RAN 108, gNB 202, CU 204, DU 206, NCR 302, NCR-MT 304, NCR-Fwd 306, RIS 402, RIS-MT 404, RIS-Fwd 406, gNB (satellite) 504, source gNB 504A, target gNB 504B, and / or NTN gateway 508) can be implemented by various parts. Parts used to implement the system and its components can include hardware, firmware, software, or combinations thereof. In some examples, one or more devices can be configured to serve as or otherwise implement the system and its components shown and described herein. In examples involving more than one device, the respective devices can be connected to or otherwise communicate with each other in a variety of different ways, such as directly or indirectly via wired or wireless networks.

[0140] Based on some example implementations, regarding Figure 10At least some of the methods in the described method 1000 can be performed by a device including components for performing the function of the method. Similarly, regarding Figure 11A and Figure 11B At least some of the methods in the described method 1100 can be performed by a device including components for performing the function of the method. And regarding... Figure 12 At least some of the methods in the described method 1200 can be performed by a means including components for performing the function of the method. Examples of suitable means may include user equipment, user facilities, user terminals, etc. Other examples of suitable means may include RF repeaters, NCRs, RISs, etc. Other examples of suitable means may include aerospace platforms, satellites, gNBs (e.g., gNB-DU, gNB-CU), ng-eNBs, or any suitable means such as servers, hosts, or nodes.

[0141] Figure 13 An apparatus 1300 implemented according to some examples of the present disclosure is shown, wherein components for performing various functions are individually or, under the guidance of one or more computer programs from a computer-readable storage medium or other memory, such as computer memory, comprise hardware. The apparatus may include one or more of each of a plurality of components, such as, for example, processing circuitry 1302 connected to a computer-readable storage medium or other memory 1304.

[0142] Processing circuitry 1302 may comprise one or more processors individually or in combination with one or more computer-readable storage media. Processing circuitry is typically any computer hardware capable of processing information (e.g., data, computer programs, and / or other suitable electronic information). Processing circuitry consists of a collection of electronic circuits, some of which may be packaged as integrated circuits or multiple interconnected integrated circuits (sometimes more commonly referred to as "chips"). Processing circuitry may be configured to execute computer programs, which may be stored on the processing circuitry or otherwise stored in memory 1304 (of the same or another device).

[0143] Depending on the specific implementation, the processing circuit 1302 may be multiple processors, a multi-core processor, or some other type of processor. Furthermore, the processing circuit may be implemented using multiple heterogeneous processor systems, where the main processor resides on a single chip along with one or more auxiliary processors. As another illustrative example, the processing circuit may be a symmetric multiprocessor system containing multiple processors of the same type. In yet another example, the processing circuit may be embodied as or otherwise include one or more ASICs, FPGAs, etc. Therefore, while the processing circuit is capable of executing a computer program to perform one or more functions, the various examples of processing circuits are capable of performing one or more functions without the assistance of a computer program. In any case, the processing circuit may be appropriately programmed to perform functions or operations implemented according to the examples of this disclosure.

[0144] Memory 1304 is typically any computer hardware capable of temporarily and / or permanently storing information (e.g., data, computer programs, instructions 1306 (e.g., computer-readable program code), and / or other suitable information). Memory may include volatile and / or non-volatile memory and may be fixed or removable. Examples of suitable memory include recording media, random access memory (RAM), read-only memory (ROM), hard disk drives, flash memory, thumb drives, removable computer disks, optical disks, or some combination thereof.

[0145] Memory 1304 is a non-transitory device capable of storing information. An example of a suitable memory is a computer-readable storage medium, distinguishable from a computer-readable transport medium capable of carrying information from one location to another. Examples of suitable computer-readable transport media include electronic carrier signals, telecommunication signals, or some combination thereof. As used herein, the term "non-transitory" is a limitation of the medium itself (i.e., tangible, not signaling), not a limitation of the persistence of data storage (e.g., RAM versus ROM). As used herein, a computer-readable medium generally refers to a computer-readable storage medium or a computer-readable transport medium. A computer-readable medium is any entity or device capable of storing and carrying information such as one or more computer programs or portions thereof.

[0146] In addition to memory 1304 (e.g., a computer-readable storage medium), processing circuitry 1302 may also be connected to one or more interfaces for displaying, sending, and / or receiving information. Interfaces may include communication interface 1308 and / or one or more user interfaces. Communication interfaces may be configured to send and / or receive information, such as to and / or from other devices(s), networks(s), etc. Communication interfaces may be configured to send and / or receive information via physical (wired) and / or wireless communication links. Examples of suitable communication interfaces include network interface controllers (NICs), wireless NICs (WNICs), etc.

[0147] The user interface may include a display 1310 and / or one or more user input interfaces 1312. The display may be configured to present or otherwise display information to a user; suitable examples include liquid crystal displays (LCDs), light-emitting diode (LED) displays, organic LED (OLED) displays, active-matrix OLEDs (AMOLEDs), etc. The user input interfaces may be wired or wireless and may be configured to receive information from a user into the device, such as for processing, storage, and / or display. Suitable examples of user input interfaces include microphones, image or video capture devices, keyboards or keypads, joysticks, touch-sensitive surfaces (separate from or integrated into the touchscreen), biometric sensors, etc. The user interface may also include one or more interfaces for communicating with peripheral devices such as printers, scanners, etc.

[0148] The combination of operations supporting the implementation of the example implementation of this disclosure is supported by the processing circuitry 1302 executing the instructions 1306 or storing the instructions in the memory 1304. In this way, the apparatus 1300 may include at least one processing circuit and at least one memory coupled to the at least one processing circuit, wherein the at least one processing circuit is configured to execute instructions stored in the at least one memory. It will also be understood that one or more functions, and combinations of functions, may be implemented by a dedicated hardware-based computer system and / or processing circuitry, or a combination of dedicated hardware and program code instructions, performing the specified functions.

[0149] Some example implementations of this disclosure can also be executed as a computer process defined by one or more computer programs or portions thereof. Example implementations of this disclosure can be executed by executing at least a portion of a computer program including instructions. The computer program can be in source code form, object code form, or some intermediate form. The computer program can be stored on a computer-readable medium that can be read by a computer, processing circuitry, or other suitable means. As mentioned above, for example, the computer program can be stored in memory such as a computer-readable storage medium. Additionally or alternatively, for example, the computer program can be stored on a computer-readable transmission medium. The coding of software used to perform example implementations of this disclosure is entirely within the scope of those skilled in the art.

[0150] As will be understood, any suitable instructions may be loaded from memory or a computer-readable medium (e.g., a computer-readable storage medium, a computer-readable transmission medium) onto a computer, processing circuitry, or other programmable means to produce a particular machine, such that the particular machine becomes a component for implementing the functions specified herein. Instructions may also be stored in a computer-readable medium that can direct a computer, processing circuitry, or other programmable means to function in a particular manner to produce a particular machine or a particular article of manufacture. In some examples, instructions stored in a computer-readable medium can produce an article of manufacture, wherein the article of manufacture becomes a component for implementing the functions described herein. Instructions may be retrieved from a computer-readable medium and loaded onto a computer, processing circuitry, or other programmable means to configure the computer, processing circuitry, or other programmable means to perform operations to be performed on or by the computer, processing circuitry, or other programmable means.

[0151] The retrieval, loading, and execution of instructions, including program code instructions, can be performed sequentially, such that one instruction is retrieved, loaded, and executed at a time. In some example implementations, retrieval, loading, and / or execution can be performed in parallel, such that multiple instructions are retrieved, loaded, and / or executed together. The execution of program code instructions can produce computer-implemented processes, such that the instructions, executed by a computer, processing circuitry, or other programmable device, provide operations for implementing the functions described herein.

[0152] As stated above and reiterated below, this disclosure includes, but is not limited to, the following example implementations.

[0153] Clause 1. A method comprising: receiving radio access service from a source node, wherein at least one radio frequency (RF) repeater is used to serve one or more user equipments (UEs) for radio transmissions from or to the source node; performing a handover of one or more UEs or at least one RF repeater from the source node to a target node; and sending handover-related auxiliary information to the target node to assist the target node in making a determination regarding: using at least one RF repeater to serve one or more UEs, and at least one beam of the at least one RF repeater for serving each of the at least one UE.

[0154] Clause 2. The method according to Clause 1, wherein the source node and the target node are first aerospace platforms in a non-terrestrial network (NTN), and the at least one RF repeater includes at least one of a network-controlled repeater (NCR) or a reconfigurable smart surface (RIS).

[0155] Clause 3. The method according to Clause 1 or Clause 2, wherein the method is performed by at least one RF repeater, and the handover is a handover by at least one RF repeater from the source node to the target node.

[0156] Clause 4. The method according to Clause 3, wherein the auxiliary information identifies each of the one or more UEs and one or more beams of the at least one RF repeater for serving each UE.

[0157] Clause 5. According to the method of Clause 4, one or more beams of at least one RF repeater are indicated by one or more beam pairs, and each beam pair in the one or more beam pairs includes the beam of at least one RF repeater and the beam of the source node.

[0158] Clause 6. The method according to Clause 4 or Clause 5, wherein the auxiliary information further identifies or includes at least one of the following: the one or more beams of the at least one RF repeater for serving each UE at different times; trajectory information of the source node at those different times; at least one of the start time or stop time of using the at least one RF repeater to serve each UE; or at least one of the time or location of the source node when the source node selects one or more beams of the at least one RF repeater for serving each UE, or when one or more measurements of making that selection are performed.

[0159] Clause 7. The method according to any one of Clauses 1 to 6, wherein the method is performed by a UE in one or more UEs, and the handover is a handover of the UE from the source node to the target node.

[0160] Clause 8. The method according to Clause 7, wherein the auxiliary information identifies the at least one RF repeater and one or more beams of the at least one RF repeater for serving the UE.

[0161] Clause 9. The method of Clause 8, wherein the auxiliary information further identifies or includes at least one of the following: the one or more beams of the at least one RF repeater used to serve the UE at different times; trajectory information of the source node at the different times; at least one of the start time or stop time of using the at least one RF repeater to serve the UE; or at least one of the time or location of the source node when the source node selects one or more beams of the at least one RF repeater used to serve the UE, or when one or more measurements of making such selection are performed.

[0162] Clause 10. The method according to any one of Clauses 1 to 9, wherein the auxiliary information is sent during the handover of one or more UEs or at least one RF repeater, in a handover completion message, or after the handover of one or more UEs or at least one RF repeater, in a response to an information request.

[0163] Clause 11. The method according to Clause 10, wherein performing a handover includes sending a handover completion message including auxiliary information to the target node.

[0164] Clause 12. The method according to Clause 10 or Clause 11, wherein the method further comprises: receiving an information request from a target node; and sending a response to the information request to the target node, the response including auxiliary information.

[0165] Clause 13. An apparatus comprising: at least one memory configured to store instructions; and at least one processing circuit configured to access the at least one memory and execute the instructions to cause the apparatus to perform a method according to any one of Clauses 1 to 12.

[0166] Clause 14. An apparatus comprising components for performing the method according to any one of Clauses 1 to 12.

[0167] Clause 15. A computer-readable medium comprising instructions that, in response to execution by at least one processing circuit, cause a device to perform a method according to any one of Clauses 1 to 12.

[0168] Clause 16. A computer-readable storage medium comprising instructions that, in response to execution by at least one processing circuit, cause a device to perform a method according to any one of Clauses 1 to 12.

[0169] Clause 17. A computer program comprising instructions that, in response to execution by at least one processing circuit, cause a device to perform a method according to any one of Clauses 1 to 12.

[0170] Clause 18. A method comprising: providing radio access service by a source node, wherein at least one radio frequency (RF) repeater is used to serve one or more user equipments (UEs) for radio transmissions from or to the source node; initiating a handover of one or more UEs and at least one RF repeater from the source node to a target node; and sending to the target node auxiliary information relating to the handover of one or more UEs or at least one RF repeater, the auxiliary information being used to assist the target node in making a determination regarding: using at least one RF repeater to serve one or more UEs, and at least one beam of the at least one RF repeater for serving at least one UE.

[0171] Clause 19. The method according to Clause 18, wherein the source node and the target node are first aerospace platforms in a non-terrestrial network (NTN), and the at least one RF repeater includes at least one of a network-controlled repeater (NCR) or a reconfigurable smart surface (RIS).

[0172] Clause 20. The method pursuant to Clause 18 or Clause 19, wherein the auxiliary information is transmitted in relation to a handover of one or more UEs, and wherein the auxiliary information identifies the at least one RF repeater and one or more beams of the at least one RF repeater for serving the UE.

[0173] Clause 21. The method according to Clause 20, wherein one or more beams of at least one RF repeater are indicated by one or more beam pairs, and each of the one or more beam pairs includes the beam of at least one RF repeater and the beam of the source node.

[0174] Clause 22. According to the method of Clause 20 or Clause 21, the auxiliary information further identifies or includes at least one of the following: one or more beams of at least one RF repeater for serving the UE at different times; trajectory information for the source node at different times; or at least one of the start time or stop time of using at least one RF repeater to serve the UE.

[0175] Clause 23. The method according to any of Clauses 18 to 22, wherein the auxiliary information is transmitted with regard to the handover of the at least one RF repeater, and wherein the auxiliary information identifies each of the one or more UEs and one or more beams of the at least one RF repeater for serving each UE.

[0176] Clause 24. The method according to Clause 23, wherein the auxiliary information further identifies or includes at least one of the following: one or more beams of at least one RF repeater for serving each UE at different times; trajectory information for the source node at different times; or at least one of the start time or stop time of using at least one RF repeater to serve each UE.

[0177] Clause 25. The method according to any one of Clauses 18 to 24, wherein the method further comprises: making a selection of one or more beams for serving each UE based on one or more measurements performed for one or more UEs; and recording at least one of the time or location of the source node when the selection is made, and wherein the auxiliary information includes at least one of the time or location of the source node when the selection is made and when the one or more measurements are performed.

[0178] Clause 26. The method of any of Clauses 18 to 25, wherein the auxiliary information indicates one or more other UEs not served by the at least one RF repeater to assist the target node in determining whether to select any of the other one or more UEs to be served by at least one beam of the at least one RF repeater.

[0179] Clause 27. An apparatus comprising: at least one memory configured to store instructions; and at least one processing circuit configured to access the at least one memory and execute the instructions to cause the apparatus to perform a method according to any one of Clauses 18 to 26.

[0180] Clause 28. An apparatus comprising components for performing the method pursuant to any one of Clauses 18 to 26.

[0181] Clause 29. A computer-readable medium comprising instructions that, in response to execution by at least one processing circuit, cause a device to perform a method according to any one of Clauses 18 to 26.

[0182] Clause 30. A computer-readable storage medium comprising instructions that, in response to execution by at least one processing circuit, cause a device to perform a method according to any one of Clauses 18 to 26.

[0183] Clause 31. A computer program comprising instructions that, in response to execution by at least one processing circuit, cause a device to perform a method according to any one of Clauses 18 to 26.

[0184] Clause 32. A method comprising: performing a handover of one or more user equipment (UEs) and at least one radio frequency (RF) repeater for serving the one or more UEs from a source node to a target node; receiving at the target node auxiliary information relating to the handover of the one or more UEs or the at least one RF repeater; based on the auxiliary information, making a determination regarding: using the at least one RF repeater to serve the one or more UEs, and at least one beam of the at least one RF repeater for serving each of the at least one UE; and based on the determination, providing radio access service from the target node to the one or more UEs, wherein the at least one RF repeater is used to serve at least one of the one or more UEs for radio transmissions from or to the target node.

[0185] Clause 33. The method according to Clause 32, wherein the source node and the target node are first aerospace platforms in a non-terrestrial network (NTN), and the at least one RF repeater includes at least one of a network-controlled repeater (NCR) or a reconfigurable smart surface (RIS).

[0186] Clause 34. The method according to Clause 32 or Clause 33, wherein the auxiliary information is received from the source node or at least one RF repeater, and the auxiliary information identifies each of the one or more UEs and one or more beams of the at least one RF repeater for serving each UE.

[0187] Clause 35. The method of Clause 34, wherein the auxiliary information further identifies or includes at least one of the following: the one or more beams of the at least one RF repeater for serving each UE at different times; trajectory information of the source node at those different times; at least one of the start time or stop time of using the at least one RF repeater to serve each UE; or at least one of the time or location of the source node when the source node selects one or more beams of the at least one RF repeater for serving each UE, or when one or more measurements of making that selection are performed.

[0188] Clause 36. The method according to any one of Clauses 32 to 35, wherein the auxiliary information for each UE is received from the UE, and the auxiliary information identifies at least one RF repeater and one or more beams of the at least one RF repeater for serving the UE.

[0189] Clause 37. The method according to Clause 36, wherein the auxiliary information further identifies or includes at least one of the following: the one or more beams of the at least one RF repeater used to serve the UE at different times; trajectory information of the source node at those different times; at least one of the start time or stop time of using the at least one RF repeater to serve the UE; or at least one of the time or location of the source node when the source node selects one or more beams of the at least one RF repeater used to serve the UE, or when one or more measurements of making that selection are performed.

[0190] Clause 38. The method according to any one of Clauses 32 to 37, wherein auxiliary information is received from the source node and the auxiliary information indicates one or more other UEs not served by at least one RF repeater, and wherein a further determination is made regarding whether to select any of the other one or more UEs to be served by at least one beam of at least one RF repeater.

[0191] Clause 39. The method of any one of Clauses 32 to 38, wherein the auxiliary information is received from the source node in conjunction with the handover of one or more UEs or at least one RF repeater.

[0192] Clause 40. The method of any of Clauses 32 to 39, wherein the auxiliary information is received from the at least one RF repeater during the handover of the at least one RF repeater, in a handover completion message, or after the handover of the at least one RF repeater is completed, in a response to an information request.

[0193] Clause 41. The method according to Clause 40, wherein performing a handover includes receiving a handover completion message including auxiliary information from the at least one RF repeater.

[0194] Clause 42. The method according to Clause 40 or Clause 41, wherein the method further comprises: sending the information request to the at least one RF repeater; and receiving a response to the information request from the at least one RF repeater, the response including the auxiliary information.

[0195] Clause 43. The method according to any one of Clauses 32 to 42, wherein the auxiliary information for each of one or more UEs is received from the UE during the handover of the UE, in a handover completion message, or after the handover of the UE is completed, in a response to an information request.

[0196] Clause 44. The method according to Clause 43, wherein performing a handover includes receiving a handover completion message from the UE including auxiliary information for the UE.

[0197] Clause 45. The method pursuant to Clause 43 or Clause 44, wherein the method further comprises: sending an information request to the UE; and receiving a response to the information request from the UE, the response including auxiliary information for the UE.

[0198] Clause 46. An apparatus comprising: at least one memory configured to store instructions; and at least one processing circuit configured to access the at least one memory and execute the instructions to cause the apparatus to perform a method according to any one of Clauses 32 to 45.

[0199] Clause 47. An apparatus comprising components for performing the method pursuant to any one of Clauses 32 to 45.

[0200] Clause 48. A computer-readable medium comprising instructions that, in response to execution by at least one processing circuit, cause a device to perform a method according to any one of Clauses 32 to 45.

[0201] Clause 49. A computer-readable storage medium comprising instructions that, in response to execution by at least one processing circuit, cause a device to perform a method according to any one of Clauses 32 to 45.

[0202] Clause 50. A computer program comprising instructions that, in response to execution by at least one processing circuit, cause a device to perform a method according to any one of Clauses 32 to 45.

[0203] Benefiting from the teachings presented in the foregoing description and associated drawings, those skilled in the art to which this disclosure pertains will conceive of numerous modifications and other implementations of this disclosure set forth herein. Therefore, it should be understood that this disclosure is not limited to the specific implementations disclosed, and that modifications and other specific implementations are intended to be included within the scope of the appended claims. Furthermore, although the foregoing description and associated drawings describe exemplary implementations in the context of certain example combinations of elements and / or functions, it should be understood that different combinations of elements and / or functions may be provided by alternative implementations without departing from the scope of the appended claims. In this regard, for example, combinations of elements and / or functions different from those explicitly described above are also contemplated as being set forth in some of the appended claims. Although specific terminology is used herein, it is used only in a general and descriptive sense and not for limiting purposes.

Claims

1. A device for communication, comprising: At least one memory is configured to store instructions; as well as At least one processing circuit is configured to access the at least one memory and execute the instructions to cause the device to at least: Receive radio access service from the source node, wherein at least one radio frequency (RF) repeater is used to serve one or more user equipments (UEs) for radio transmissions from or to the source node. Perform a handover from the source node to the target node for one or more UEs or at least one RF repeater; as well as The target node is sent auxiliary information related to the handover, which assists the target node in making the following determinations: using the at least one RF repeater to serve the one or more UEs, and at least one beam of the at least one RF repeater for serving each of the at least one UE.

2. The apparatus of claim 1, wherein the source node and the target node are a first aerospace platform in a non-terrestrial network (NTN), and the at least one RF repeater comprises at least one of a network control repeater (NCR) or a reconfigurable smart surface (RIS).

3. The apparatus of claim 1, wherein the method is performed by the at least one RF repeater, and the handover is a handover by the at least one RF repeater from the source node to the target node.

4. The apparatus of claim 3, wherein the auxiliary information identifies each of the one or more UEs and one or more beams of the at least one RF repeater for serving each UE.

5. The apparatus of claim 4, wherein the one or more beams of the at least one RF repeater are indicated by one or more beam pairs, and each of the one or more beam pairs includes the beam of the at least one RF repeater and the beam of the source node.

6. The apparatus of claim 4, wherein the auxiliary information further identifies or includes at least one of the following: The one or more beams of the at least one RF repeater used to serve each UE at different times; The trajectory information of the source node at the different times; Use the at least one RF repeater to serve at least one of the start time or stop time of each UE; or The source node's time or location is at least one of the following when the source node selects one or more beams for serving each UE, or when one or more measurements are performed to make the selection.

7. The apparatus of claim 1, wherein the method is performed by a UE among the one or more UEs, and the handover is a handover of the UE from the source node to the target node.

8. The apparatus of claim 7, wherein the auxiliary information identifies the at least one RF repeater and one or more beams of the at least one RF repeater for serving the UE.

9. The apparatus of claim 8, wherein the auxiliary information further identifies or includes at least one of the following: The one or more beams of the at least one RF repeater used to serve the UE at different times; The trajectory information of the source node at the different times; The at least one RF repeater is used to serve at least one of the start time or stop time of the UE; or The source node's time or location is at least one of the following when the source node selects one or more beams for serving the at least one RF repeater, or when one or more measurements are performed to make the selection.

10. The apparatus of claim 1, wherein the auxiliary information is sent in a handover completion message during the handover of the one or more UEs or the at least one RF repeater, or in a response to an information request after the handover of the one or more UEs or the at least one RF repeater.

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