Mobility robustness optimization for handover of user equipment to radio access backhaul

Abstract

Various example embodiments relate to methods and apparatuses for mobility robustness optimization for user equipment handover to a wireless access backhaul. An apparatus can include at least one processor and at least one memory. The at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus at least to detect a failure or near-failure associated with a handover procedure; and send, to a network node, a report including a time of occurrence of the failure or near-failure. The target network node for the handover procedure is a mobile wireless access backhaul node.

Description

Technical Field

[0001] This disclosure relates generally to communication technologies, and in particular to methods and apparatus for optimizing mobility robustness during user equipment backhaul handover to radio access. Background Technology

[0002] Some abbreviations that can be found in the specification and / or drawings are defined here as follows:

[0003] 3GPP has initiated a research project on additional topology enhancements for 5G New Radio (NR), including the topic of Radio Access Backhaul (WAB). Radio Access Backhaul refers to the method of wirelessly connecting the Radio Access Network (RAN) to the Core Network (CN) using microwave, millimeter-wave (mm-Wave), or satellite communication technologies. Compared to traditional wired solutions (typically via fiber optic or Ethernet cables), Radio Access Backhaul offers greater flexibility, scalability, and cost-effectiveness. It provides faster deployment, seamless communication, and easy expansion of network coverage. Therefore, Radio Access Backhaul is expected to be an important complement to wired access backhaul in 5G and beyond communication systems. Summary of the Invention

[0004] The following provides a brief overview of example embodiments to offer a basic understanding of some aspects of the various embodiments. It should be noted that the content of this invention is not intended to identify key features of the essential elements or define the scope of the embodiments, and its sole purpose is to introduce some concepts in a simplified form as a prelude to the more detailed description provided below.

[0005] In a first aspect, an example embodiment of an apparatus is provided. The apparatus may include at least one processor and at least one memory. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus to at least: detect a failure or near failure associated with a handover process for the apparatus, wherein the target network node for the handover process is a mobile radio access backhaul node; and send a report to the network node including the time of occurrence of the failure or near failure.

[0006] In a second aspect, an example embodiment of an apparatus is provided. The apparatus may include at least one processor and at least one memory. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus to at least: receive a report indicating a failure of a user equipment (UE) associated with a handover process; send a request for mobility information to a target network node for the UE during the handover process, the target network node being a mobile radio access backhaul node, the request indicating a first time step; receive mobility information from the target network node at the first time step and at a second time step; enhance the UE report based on the received mobility information from the target network node at the first and second time steps; and send the enhanced report to an optimization entity.

[0007] In a third aspect, an example embodiment of an apparatus is provided. The apparatus may include at least one processor and at least one memory. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus to at least: establish a connection with a user equipment via a handover or reconstruction process after a handover process; receive a report of failure or near failure associated with the handover process from the user equipment; enhance the report based on mobility information of the apparatus at a first time and a second time, the first time being the time when the failure or near failure associated with the handover process occurs, the time when the handover process is successfully executed, or the time when the reconstruction process is executed, the second time being the time when the apparatus allows the user equipment to hand over from a source network node to the apparatus during the handover process; and send the enhanced report to an optimization entity.

[0008] In a fourth aspect, an example embodiment of an apparatus is provided. The apparatus may include at least one processor and at least one memory. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus to at least: re-establish a connection with a user equipment through a reconstruction process; receive a failure report from the user equipment associated with the handover process, the report indicating a second moment in which the failure occurred; enhance the report using mobility information from a first moment and a second moment, the first moment referring to the time when the connection with the user equipment was re-established; and send the enhanced report to an optimization entity.

[0009] In a fifth aspect, an example embodiment of an apparatus is provided. The apparatus may include at least one processor and at least one memory. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus to at least: receive a request from a network node for mobility information at a first moment; and send a response to the network node containing mobility information of the apparatus at a first moment and a second moment, the second moment referring to the time during which the apparatus allows a user device to switch from a source network node to the apparatus during a handover process.

[0010] In a sixth aspect, an example embodiment of an apparatus is provided. The apparatus may include at least one processor and at least one memory. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus to at least: receive a report of failure or near failure associated with a handover process for a user equipment to a target network node implemented as a mobile radio access backhaul node, the report containing mobility information of the target network node; and, based on the mobility information of the target network node, determine whether the failure or near failure is caused by the mobility of the target network node.

[0011] In a seventh aspect, an example embodiment of an apparatus is provided. The apparatus may include at least one processor and at least one memory. The at least one memory may store instructions that, when executed by the at least one processor, cause the apparatus to at least: receive a report of a failure or near failure associated with a handover process for a user equipment to a target network node implemented as a mobile radio access backhaul node, the report indicating a first moment when the failure or near failure associated with the handover process occurs, or a first moment when a reconstruction process is executed after a failure associated with the handover process; send a request for mobility information of the target network node to the target network node, the request indicating the first moment; receive mobility information of the target network node at the first moment and mobility information of the target network node at a second moment from the target network node, the second moment referring to the time when the target network node allows the user equipment to handover during the handover process; and determine, based on the mobility information of the target network node at the first moment and the second moment, whether the failure or near failure is caused by the mobility of the target network node.

[0012] Other aspects provide exemplary embodiments of methods, apparatuses, computer-readable media, and computer programs that generally correspond to the foregoing aspects, and for convenience, repeated descriptions thereof are omitted herein.

[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, regardless of whether such features or elements are explicitly combined or otherwise described in the particular exemplary embodiments described herein. This disclosure is intended to be read holistically such that any separable feature or element of this disclosure should be considered composable in any aspect and exemplary embodiment of that feature or element, unless the context of this disclosure explicitly states otherwise.

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

[0015] Some exemplary embodiments will now be described by way of non-limiting example with reference to the accompanying drawings.

[0016] Figure 1 This is a schematic diagram illustrating an example communication environment in which example embodiments of the present disclosure can be implemented.

[0017] Figure 2 This is a signaling diagram illustrating a process according to an example embodiment of the present disclosure.

[0018] Figure 3 This is a signaling diagram illustrating a process according to an example embodiment of the present disclosure.

[0019] Figure 4 This is a signaling diagram illustrating a process according to an example embodiment of the present disclosure.

[0020] Figure 5 This is a signaling diagram illustrating a process according to an example embodiment of the present disclosure.

[0021] Figure 6 This is a signaling diagram illustrating a process according to an example embodiment of the present disclosure.

[0022] Figure 7 This is a signaling diagram illustrating a process according to an example embodiment of the present disclosure.

[0023] Figure 8 This is a signaling diagram illustrating a process according to an example embodiment of the present disclosure.

[0024] Figure 9 This is a flowchart illustrating a method according to an example embodiment of the present disclosure.

[0025] Figure 10 This is a flowchart illustrating a method according to an example embodiment of the present disclosure.

[0026] Figure 11 This is a flowchart illustrating a method according to an example embodiment of the present disclosure.

[0027] Figure 12 This is a flowchart illustrating a method according to an example embodiment of the present disclosure.

[0028] Figure 13 This is a flowchart illustrating a method according to an example embodiment of the present disclosure.

[0029] Figure 14 This is a flowchart illustrating a method according to an example embodiment of the present disclosure.

[0030] Figure 15 This is a flowchart illustrating a method according to an example embodiment of the present disclosure.

[0031] Figure 16A This is a block diagram illustrating an apparatus according to an exemplary embodiment of the present disclosure.

[0032] Figure 16B This is a block diagram illustrating an apparatus according to an exemplary embodiment of the present disclosure.

[0033] Figure 16C This is a block diagram illustrating an apparatus according to an exemplary embodiment of the present disclosure.

[0034] Throughout the accompanying drawings, the same or similar reference numerals denote the same or similar elements. Repeated descriptions of the same elements will be omitted. Detailed Implementation

[0035] In the following description, some exemplary embodiments are described in detail with reference to the accompanying drawings. Specific details are included in the following description for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some instances, well-known circuits, technologies, and components are shown in block diagram form to avoid obscuring the described concepts and features.

[0036] As used herein, the term "network" or "communication network" refers to a network that conforms to any suitable communication standard, such as Long Term Evolution (LTE), LTE-A Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed ​​Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), Wi-Fi, Non-Terrestrial Network (NTN), etc. Furthermore, communication between terminal devices and network devices / elements / nodes in a communication network can be performed according to any suitable generated communication protocol, including but not limited to fourth-generation (4G), 4.5G, fifth-generation (5G), future sixth-generation (6G), the IEEE 802.11 communication protocol, and / or any other currently known or future-developed protocols. Embodiments of this disclosure can be applied to various communication systems. Given the rapid development in communications, there will naturally be future types of communication technologies and systems that can implement this disclosure. The scope of this disclosure should not be limited to the aforementioned systems only.

[0037] As used herein, the term "network device / element / node" refers to a node in a communication network through which terminal devices receive services. A network device can refer to radio access network equipment such as a base station (BS) or access point (AP) or transmit and receive point (TRP), for example, a Node B (NodeB or NB), an evolved Node B (eNodeB or eNB), a New Radio (NR) NB (also known as a gNB), a Remote Radio Unit (RRU), a Radio Head (RH), a Remote Radio Head (RRH), a WiFi device, a repeater, a low-power node (such as a femtosecond, picosecond, etc.), depending on the terminology and technology applied. In the following description, the terms "network device / element / node," "AP device," "AP," and "TRP" are used interchangeably.

[0038] The term "terminal device" refers to any terminal device capable of wireless communication. By way of example and not limitation, a terminal device may also be referred to as a communication device, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS), station (STA), or station equipment, or access terminal (AT). Terminal devices may include, but are not limited to, mobile phones, cellular phones, smartphones, Voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image capture terminal devices (such as digital cameras), gaming terminal devices, music storage and playback devices, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop embedded devices (LEEs), laptop devices (LMEs), USB dongles, smart devices, wireless customer premises equipment (CPEs), Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or automated processing chains), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, etc. In the following description, the terms “station,” “station equipment,” “STA,” “terminal equipment,” “communication equipment,” “terminal,” “user equipment,” and “UE” are used interchangeably.

[0039] Figure 1 An example communication environment 100 in which example embodiments of the present disclosure may be implemented is shown. For example... Figure 1 As shown, the communication environment 100 may include a cellular communication network, which includes one or more base stations 120 forming a so-called radio access network (RAN). Each base station 120 may support one or more cells, and a UE 110 (only one shown) camped in a cell may establish a connection with the base station 120 to access the network and receive network services. Figure 1Two types of base stations are shown, including a fixed base station 120A and a mobile base station 120B mounted on a mobile vehicle. At least a portion of the fixed base station 120A (e.g., an antenna) is mounted on a tower, mast, or building. It should be understood that the mobile base station 120B can also be mounted on, for example, unmanned aerial vehicles (UAVs), airplanes, balloons, satellites, etc.

[0040] Mobile base station 120B can be implemented as a Radio Access Backhaul (WAB) node, comprising a base station (e.g., gNB) portion (i.e., WAB-gNB) and a mobile terminal (MT) portion (i.e., WAB-MT, also known as WAB-UE). WAB-gNB can provide a New Radio (NR) access link to the UE. WAB-MT can wirelessly connect to another NG RAN node, forming a radio connection for NR backhaul. Backhaul connectivity for WAB-gNB is provided to the serving network via one or more Protocol Data Unit (PDU) sessions established for WAB-MT. The WAB-gNB NG interface, including both the control plane and user plane, is transparently forwarded through the serving network via the backhaul PDU sessions(s). Additionally, WAB-gNB can establish an Xn interface (for both the control plane and user plane) with an adjacent NG RAN node, which is also transparently forwarded via the backhaul PDU sessions(s). UEs connected to the WAB node treat the WAB-gNB cell as a normal cell, and the UE can use existing signaling procedures to establish (multiple) PDU sessions to the UE's core network (e.g., 5G core (5GC)). Therefore, the WAB deployment is transparent to the UE.

[0041] Figure 1 The illustration depicts a scenario where a UE 110 connected to a fixed base station 120A is moving from a cell provided by base station 120A to another cell provided by WAB node 120B. A handover (HO) procedure can be performed when predetermined conditions are met to move the UE 110's connection from the cell provided by base station 120A (i.e., the source cell) to the cell provided by WAB node 120B (i.e., the target cell). Throughout this disclosure, the term "handover" can refer to both basic handover and conditional handover (CHO). The network can optimize the configuration used for the handover procedure (i.e., mobility parameters), including, for example, measurement and reporting configurations, to ensure a seamless handover of UE 110 from the source cell to the target cell, so that UE 110's communication is not interrupted. For example, WAB node 120B may follow a route near the source base station 120A (continuously or the route allows WAB node 120B to be near the source base station 120A for a sufficient amount of time and multiple times). This ensures that the source base station 120A can collect statistically significant reports, based on which the optimization entity can perform optimizations and thus apply new mobility parameters for the handover process.

[0042] However, current Mobility Robustness Optimization (MRO) features only consider UE mobility, but not the mobility of base stations (e.g., Mobile WAB (MWAB) nodes). In other words, the current MRO model cannot distinguish between handover to a MWAB node and a regular handover between two fixed base stations. The impact of both UE and MWAB-gNB mobility introduces a scenario that, if handled using the current MRO model, will lead to conflicting / incorrect optimization results, and thus suboptimal / incorrect mobility parameter selection. For example, one of the functions of the current MRO model is to detect connection failures due to premature handover, late handover, or handover to the wrong cell. If the traditional (current) Key Performance Indicators (KPIs) used for premature handover, late handover, and handover to the wrong cell are considered... Figure 1 In the scenario shown, due to the mobility of the MWAB-gNB, the KPIs will be updated incorrectly, leading to conflicting / incorrect optimization results. Therefore, the current MRO model is ineffective for UE handover to the MWAB node.

[0043] Some example embodiments of this disclosure propose a novel optimization framework for UE handover to a mobile base station (e.g., a MWAB node). Using this new optimization framework, the optimization entity can identify whether connection failure or near failure is caused by inappropriate handover configuration (i.e., mobility parameters) or by the influence of the MWAB node's mobility. To achieve this, in some example embodiments, mobility information of the MWAB node can be collected and reported to the optimization entity. Mobility information can be carried to the optimization entity, for example, in Radio Link Failure (RLF) reports, Successful Handover Reports (SHR), Successful PSCell Change Reports (SPR), or any other Self-Organizing Network (SON) / Minimized Drive Test (MDT) reports. If the mobility information indicates that the MWAB node moved a long distance and / or moved at a high speed during or shortly after handover, the optimization entity can determine that the connection failure or near failure is caused by the MWAB node's mobility. Otherwise, the optimization entity can determine that the connection failure or near failure is caused by inappropriate mobility parameters. This will help the optimization entity group UEs and derive appropriate performance indicators, such as Key Performance Indicators (KPIs) and corrective actions. Furthermore, it will help optimize entities to derive the optimal mobility parameters for the handover process. Notably, the new optimization framework is also applicable to handover between PLMNs.

[0044] In some example embodiments, new performance indicators such as KPIs are introduced for UE handover to the MWAB node. New KPIs may include, for example, premature handover to the MWAB, late handover to the MWAB, erroneous cell change to the MWAB, near-failure handover to the MWAB, and near-failure primary / secondary cell (PSCell) change to the MWAB. Similarly, throughout this disclosure, the term "handover" or "HO" encompasses both basic handover and conditional handover (CHO). In the case of a CHO, KPIs may include, for example, premature CHO to the MWAB, late CHO to the MWAB, erroneous conditional cell change to the MWAB, near-failure CHO to the MWAB, and near-failure conditional PSCell change to the MWAB. It is noteworthy that, depending on whether an inter-gNB handover or inter-PLMN handover is performed, such KPIs may be isolated per cell boundary or per PLMN.

[0045] Figure 2 An example optimization process 200 for late handover to a MWAB is illustrated according to some example embodiments of this disclosure. Process 200 can be implemented at UE 110, a base station (e.g., gNB 120A), MWAB node 120B, and optimization entity 130. Base station 120A and MWAB node 120B can be used as the source network node and target network node, respectively, during the handover process. Optimization entity 130 is configured to optimize the configuration (mobility parameters) used for the handover process. The optimization of mobility parameters can be handled in two different ways (i.e., in a centralized or distributed manner). In the case of centralized optimization, optimization entity 130 can be implemented at an Operation, Management and Maintenance (OAM) entity, RAN Intelligent Controller (RIC), or Core Network Function (NF) or node. In the case of distributed optimization, optimization entity 130 can be implemented at a RAN node (e.g., source base station 120A, target MWAB node 120B, and / or a third base station (not shown)). For ease of description, optimization entity 130 is... Figure 2 It is shown as a separate node.

[0046] Reference Figure 2 At the beginning, UE 110 may be in an RRC connected state. At point 202, data transmission may be performed between UE 110 and base station 120A currently serving UE 110. At point 204, base station 120A may configure UE 110, such as through Radio Resource Control (RRC) reconfiguration, to measure one or more neighboring cells. The measurement configuration may include one or more measurement reporting conditions, such as events. UE 110 is configured to report one or more strongest neighboring radio cells when one or more reporting conditions / events are met.

[0047] Then, UE 110 can periodically perform measurements and check whether reporting conditions are met based on the measurement configuration. If UE 110 determines at 206 that one or more reporting conditions are met, UE 110 can send a measurement report indicating at least one strongest neighboring cell to base station 120A at 208. Assume... Figure 1 In the scenario shown, UE 110 can report to base station 120A that the cell provided by MWAB node 120B is the strongest cell. As UE 110 moves away from base station 120A, the channel conditions between UE 110 and base station 120A deteriorate, and if UE 110 does not switch to a stronger cell in time, UE 110 may begin to experience radio link failure (RLF) for the serving cell provided by base station 120A.

[0048] Based on the measurement report, base station 120A can decide at 210 to initiate a handover process for UE 110 to the strongest cell provided by MWAB node 120B, and at 212 send a handover request message to the target MWAB node 120B, conveying necessary information to prepare for handover on the target side. This information includes at least the Cell Radio Network Temporary Identifier (C-RNTI) of UE 110 in the source cell and the target cell ID. In some example embodiments, such as according to a process called Xn handover, the handover request message can be sent through the Xn interface between the source base station 120A and MWAB node 120B. In some other example embodiments where there is no Xn interface between the two access nodes, MWAB node 120B can be accessed according to a process called NG Application Protocol (NGAP) handover.

[0049] In response to a handover request, the target MWAB node 120B may perform admission control at 214, such as allowing / accepting or denying the handover request. If the target MWAB node 120B decides to allow / accept the handover of UE 110, the target MWAB node 120B may record mobility information at that moment. In some example embodiments, the MWAB node 120B may record any of the following mobility information: ● Current location: It can be expressed as a geographic location, such as the latitude and longitude coordinates of MWAB node 120B and / or the cell serving MWAB node 120B, cell or tracking area code (TAC) ID.

[0050] ● Current speed: It can be expressed in kilometers per hour, miles per hour, or any other measure.

[0051] ● Distance traveled: This can be an absolute or relative distance measured in meters, kilometers, miles, etc. In the case of absolute distance, the MWAB node 120B can reset its distance counter depending on the implementation (e.g., at the start of the WAB service) and then record the travel distance periodically or for any event (e.g., admission control or switchover preparation, reconstruction, etc.). In the case of relative distance, the MWAB node 120B can reset the distance counter for any event and record the travel distance before the next event reset.

[0052] ● Current time: It can be the time used to record position, speed, and / or distance traveled.

[0053] If the target MWAB node 120B decides to allow / accept the handover of UE 110, the target MWAB node 120B may provide a handover request acknowledgment (ACK) message to the source base station 120A at 216. The handover request ACK message may include a transparent container to be sent to UE 110 as an RRC message to perform the handover, containing information required for accessing the target cell, such as the new C-RNTI in the target cell, the initial RACH resources for accessing the target cell, security information, etc. In an example embodiment, the transparent container may include an indication that the handover target network node is a MWAB node.

[0054] In response to the handover request ACK message, the source base station 120A can send a handover command to the UE 110 at 218 by forwarding the transparent container received in the handover request ACK message. As described above, the handover command may include an indication that the target network node 120B is a MWAB node. In some example embodiments, the source base station 120A may indicate to the UE 110 that the target network node 120B is a MWAB node in a message containing the handover command or in a separate message.

[0055] exist Figure 2 In the example shown, it is assumed that UE 110 has experienced a radio link failure, and at 218, UE 110 did not successfully receive a handover command. Therefore, the handover preparation is incomplete, leading to handover failure. At 220, UE 110 can detect a radio link failure (RLF) against the source cell and generate an RLF report. The RLF report may include UE 110's C-RNTI in the source cell, multiple measurement reports, an indication that the connection failure type is a handover failure (e.g., a handover to MWAB failure), etc. In the example embodiment, UE 110 may include the time of the RLF occurrence in the RLF report.

[0056] When a radio link failure is detected, UE 110 can rebuild the RRC connection through a reconstruction process. Since the target cell provided by MWAB node 120B is the strongest cell for UE 110, UE 110 can rebuild the RRC connection with MWAB node 120B in the target cell at point 222. During the reconstruction process, UE 110 can send an RRC reconstruction request message to MWAB node 120B, which provides the Physical Cell Identifier (PCI) and C-RNTI of the source cell. UE 110 can also indicate in the RRC reconstruction request that the reconstruction is due to a handover failure (e.g., a failure to hand over to MWAB). MWAB node 120B can retrieve the UE context from the source (last served) base station 120A and send an RRC reconstruction message to UE 110. When the RRC connection is successfully rebuilt, UE 110 can send an RRC reconstruction complete message to MWAB node 120B.

[0057] When the RRC connection between UE 110 and MWAB node 120B is re-established, at point 224, MWAB node 120B can retrieve the RLF report from UE 110. For example, UE 110 can indicate the availability of the RLF report in an RRC re-establishment complete message. In response to this indication, MWAB node 120B can request the RLF report by sending a UE information request message to UE 110. UE 110 can then send the RLF report to MWAB node 120B in a UE information response message.

[0058] MWAB node 120B can determine and record mobility information, such as current location, current speed, distance traveled, and current time, at point 226. In some example embodiments, MWAB node 120B can determine and record mobility information when the RRC connection of UE 110 is re-established. For example, MWAB node 120B can identify from the C-RNTI of UE 110 received in an RRC re-establishment request message that it approved the handover of UE 110 before the re-establishment process. Then, MWAB node 120B can infer that UE 110 has experienced a handover failure, and when the RRC connection of UE 110 is successfully re-established, MWAB node 120B can determine and record mobility information. As another example, if the RRC re-establishment request received from UE 110 indicates that the reason for the re-establishment is a handover failure (e.g., a failure to hand over to MWAB), then MWAB node 120B can determine and record mobility information when the re-establishment process is successfully performed. In some other example embodiments, MWAB node 120B can determine mobility information when a radio link failure occurs. For example, MWAB node 120B can periodically measure and store mobility information. When MWAB node 120B receives an RLF report indicating the time of the RLF occurrence from UE 110, MWAB node 120B can retrieve the mobility information at the time of the RLF occurrence from historical mobility information data.

[0059] At 228, MWAB node 120B can enhance the received RLF report based on the mobility information determined at 214 (i.e., mobility information when allowing / accepting / approving the handover of UE 110 during the handover preparation phase) and the mobility information determined at 226 (i.e., mobility information when the RRC connection of UE 110 is re-established or when a radio link failure occurs). In an example embodiment, MWAB node 120B can add mobility information to the RLF report. If the mobility information does not include time, MWAB node 120B can include chronologically ordered mobility information in the RLF report, and / or can add time-related labels to the mobility information. For example, the mobility information determined at 214 can be labeled as “initial” or “HO preparation” mobility information, and the mobility information determined at 226 can be labeled as “final” or “RLF / re-establishment” mobility information. If the mobility information includes time, no labels are required. Alternatively or additionally, MWAB node 120B can process mobility information identified at locations 214 and 226 and add new information to the RLF report. For example, MWAB node 120B can calculate average or maximum speed, and / or the distance traveled between the “initial” and “final” times, and include such calculated data in the RLF report. It should be understood that MWAB node 120B can collect and calculate additional mobility-related information to enhance the RLF report.

[0060] Then, MWAB node 120B can send an enhanced RLF report to optimization entity 130 at 230. In another example embodiment, MWAB node 120B can send an enhanced RLF report to source base station 120A at 232. MWAB node 120B is able to identify the source (last served) cell of UE 110 based on the RRC reconstruction request message or RLF report received from UE 110. Then, source base station 120A can forward the enhanced RLF report to optimization entity 130 at 234.

[0061] Upon receiving an enhanced RLF report, at point 236, optimization entity 130 can determine, based on mobility information, whether the radio link failure / handover failure is caused by the mobility of MWAB node 120B. A set of rules and relevant thresholds can be used at optimization entity 130 to determine whether the radio link failure / handover failure is caused by the mobility of MWAB node 120B. For example, if the mobility information indicates that the location of MWAB node 120B at the RLF occurrence time or connection re-establishment time differs significantly from its location at the handover admission control time (i.e., handover preparation time), then MWAB node 120B has traveled a long distance during the period from handover preparation time to RLF occurrence or connection re-establishment time, and / or MWAB node 120B has a high speed during handover preparation time or a high average / maximum speed during the period from handover preparation time to RLF occurrence or connection re-establishment time, optimization entity 130 can determine that the radio link failure / handover failure is caused by the mobility of MWAB node 120B, rather than by current mobility parameters. If the mobility information does not indicate significant movement of MWAB node 120B, the optimization entity 130 can determine that the radio link failure / handover failure is caused by inappropriate mobility parameters of the currently applied device, rather than by the mobility of MWAB node 120B.

[0062] If optimization entity 130 determines that the radio link failure / handover failure is caused by the mobility of MWAB node 120B, then optimization entity 130 can ignore the enhanced RLF report at 238, because the currently applied mobility parameters may be appropriate. If optimization entity 130 determines that the radio link failure / handover failure is not caused by the mobility of MWAB node 120B, then the currently applied mobility parameters may be incorrect and need to be optimized. Then, optimization entity 130 can update the performance indicators (e.g., key performance indicators (KPIs)) for the handover process at 238 based on the enhanced RLF report. Figure 2 In the example scenario shown, UE 110 successfully connects to the target cell provided by MWAB node 120B after a handover failure, indicating that the handover process was initiated too late. Therefore, optimization entity 130 can update the KPI for the late handover to MWAB at point 238. It should be understood that optimization entity 130 is capable of collecting RLF and other reports from multiple UEs and RAN nodes and updating the KPI based on these reports. The KPI will be used to optimize the handover process between two RAN nodes or between two specific cells.

[0063] Figure 3Another example optimization process 300 for late handover to the MWAB is illustrated according to some example embodiments of this disclosure. In process 300, it is also assumed that UE 110 is connected to base station 120A. At 302, data transmission can be performed between UE 110 and base station 120A, and base station 120A can configure UE 110 using measurement configuration at 304. However, due to various possible reasons, UE 110 fails to handover to the appropriate cell before experiencing a radio link failure. For example, measurement report conditions are not met (reason A), measurement reports are not successfully transmitted due to poor channel conditions (reason B), or UE 110 does not receive the handover command (reason C) because the source base station 120A spends too much time processing the measurement report. Therefore, MWAB node 120B may not receive the handover request and perform admission control for UE 110, and handover preparation is incomplete.

[0064] At point 306, UE 110 can detect a radio link failure (RLF) for the source cell and generate an RLF report. The RLF report may include: UE 110's C-RNTI in the source cell, measurements acquired prior to the radio link failure, an indication that the connection failure type is a handover failure (e.g., a handover to MWAB failure), and the time the RLF occurred. In an example embodiment, UE 110 may also include an RLF reason in the RLF report. The RLF reason may be one of the reasons A, B, and C described above.

[0065] In response to a radio link failure, UE 110 can select an appropriate cell to rebuild its RRC connection. Figure 3 In the example shown, it is assumed that UE 110 re-establishes an RRC connection at 308 in a cell provided by MWAB node 120B.

[0066] When the RRC connection of UE 110 is successfully re-established, MWAB node 120B can determine and record the mobility information of MWAB node 120B at 310. In the example embodiment, if the re-establishment request received from UE 110 indicates that the re-establishment reason is a handover failure (e.g., handover to MWAB failed), then when the re-establishment process is successfully executed, MWAB node 120B can determine and record the mobility information.

[0067] When the RRC connection between UE 110 and MWAB node 120B is re-established, at point 312, MWAB node 120B can retrieve the RLF report from UE 110. For example, UE 110 can indicate the availability of the RLF report in an RRC re-establishment complete message. In response to this indication, MWAB node 120B can request the RLF report by sending a UE information request message to UE 110. UE 110 can then send the RLF report to MWAB node 120B in a UE information response message.

[0068] At point 314, MWAB node 120B can determine, based on the RLF report, whether MWAB node 120B was the intended target RAN node for handover of UE 110 prior to the radio link failure. For example, the RLF report may include measurement results acquired at UE 110 prior to the radio link failure. If the measurement results indicate that the cell provided by MWAB node 120B prior to the radio link failure was the strongest cell for UE 110, then MWAB node 120B can determine that it is the intended target RAN node for handover of UE 110. MWAB node 120B can then determine and record mobility information at the time of the RLF occurrence, such as location, speed, distance traveled, and current time. For example, MWAB node 120B can retrieve mobility information at the time of the RLF occurrence from historical data of mobility information periodically measured and updated at MWAB node 120B. If MWAB node 120B determines at point 314 that it is not the intended target RAN node for the handover of UE 110 prior to the radio link failure, then MWAB node 120B may forward the RLF report to the intended target RAN node. In the example, MWAB node 120B may add the reconstruction time to the RLF report before forwarding the RLF report to the intended target RAN node.

[0069] At 316, MWAB node 120B can enhance the RLF report based on the mobility information determined at 310 (i.e., mobility information when the RRC connection of UE 110 is re-established) and the mobility information determined at 314 (i.e., mobility information when a radio link failure occurs). In this example, since MWAB node 120B does not perform admission control during handover preparation, MWAB node 120B can use the mobility information at the time of RLF occurrence as the mobility information at the time of handover preparation. As described above, MWAB node 120B can add mobility information when it enters the RLF report, and / or process the mobility information to add statistical information to the RLF report.

[0070] Then, MWAB node 120B can send an enhanced RLF report to optimization entity 130 at 318. In another example embodiment, MWAB node 120B can send an enhanced RLF report to source base station 120A at 320. MWAB node 120B is able to identify the source (last served) cell of UE 110 based on the RRC reconstruction request message or RLF report received from UE 110. Then, source base station 120A can forward the enhanced RLF report to optimization entity 130 at 322.

[0071] Upon receiving an enhanced RLF report, at point 324, optimization entity 130 can determine, based on mobility information, whether the radio link failure / handover failure is caused by the mobility of MWAB node 120B. In an example embodiment, the failure reasons indicated in the RLF report, such as reason A "measurement report conditions not met," reason B "measurement report not successfully transmitted due to poor channel conditions," and reason C "handover command not received," can also be used to determine whether the radio link failure / handover failure is caused by the mobility of MWAB node 120B. For example, if the RLF report indicates that the failure reason is any of reasons A through C, and the mobility information indicates significant movement (e.g., long distance) and / or high speed of MWAB node 120B, then optimization entity 130 can determine that the radio link failure / handover failure is caused by the mobility of MWAB node 120B. This improves the accuracy of determining whether the radio link failure / handover failure is caused by the mobility of MWAB node 120B. Optimization entity 130 can also use the failure reasons indicated in the RLF report to analyze the root cause of the handover failure.

[0072] If optimization entity 130 determines that the radio link failure / handover failure is caused by the mobility of MWAB node 120B, then optimization entity 130 may ignore the enhanced RLF report at point 326. If optimization entity 130 determines that the radio link failure / handover failure is not caused by the mobility of MWAB node 120B, then optimization entity 130 may update performance indicators such as KPIs used for the handover process based on the enhanced RLF report at point 326. Figure 3In the example scenario shown, it is assumed that the cell provided by MWAB node 120B was the strongest cell for UE 110 before the radio link failure, and UE 110 successfully connected to the cell provided by MWAB node 120B after the radio link failure. The optimization entity 130 can determine based on this fact that the handover process for UE 110 was initiated too late, and therefore update the KPI for the late handover to MWAB at 326. It should be understood that the optimization entity 130 can collect RLF and other reports from multiple UEs and RAN nodes, and update the KPIs based on these reports. The KPIs will be used to optimize the handover process between two RAN nodes or between two specific cells. For example, if the late handover to the MWAB indicator indicates the number of late handover failures, the optimization entity 130 can optimize mobility parameters to initiate the handover to the MWAB node / cell earlier.

[0073] Figure 4 An example optimization process 400 for premature handover to MWAB according to some example embodiments of this disclosure is illustrated. Similar to process 200 discussed above, operations 202 to 216 can be performed for handover preparation of UE 110, and repeated descriptions of these operations are omitted here. Assume that UE 110 successfully receives the handover command at 218a and handover preparation is complete. As described above, the handover command may include a new C-RNTI of UE 110 in the target cell and an indication that the target RAN node for handover is a MWAB node, or base station 120A may indicate that the target RAN node for handover is a MWAB node in a message containing the handover command or in a separate message.

[0074] In response to a handover command, UE 110 can detach from the old / source cell at 402 and attempt to synchronize with the new / target cell provided by MWAB node 120B. At 404, UE 110 can acquire downlink (DL) and uplink (UL) synchronization with the target cell and initiate a random access procedure toward the target cell. However, due to, for example, poor channel conditions between UE 110 and MWAB node 120B, the random access procedure fails, and UE 110 does not connect to MWAB node 120B.

[0075] At 406, UE 110 can detect a radio link failure (RLF) and generate an RLF report. The RLF report may include UE 110's C-RNTI in the source cell, multiple measurement reports prior to the radio link failure, an indication that the connection failure type is a handover failure (e.g., a handover to MWAB failure), and a failure cause indication (such as cause A, cause B, or cause C discussed above). In an example embodiment, UE 110 may include the time of the RLF occurrence in the RLF report.

[0076] In response to a radio link failure, UE 110 can perform cell selection and initiate a reconstruction procedure to rebuild the RRC connection. Figure 4 In the example shown, assume UE 110 selects the source cell as the strongest cell and re-establishes its RRC connection with base station 120A at point 408. Base station 120A can determine and record the time when the RRC connection of UE 110 is re-established at point 410. In the example embodiment, if the re-establishment request received from UE 110 indicates that the reason for the re-establishment is a handover failure (e.g., a failure to hand over to MWAB), or if base station 120A identifies that UE 110 has experienced a handover failure (e.g., a failure to hand over to MWAB) based on other information included in the re-establishment request, then base station 120A can determine and record the time when the RRC connection of UE 110 is re-established.

[0077] When the RRC connection between UE 110 and base station 120A is re-established, base station 120A can retrieve the RLF report from UE 110 at position 412. For example, UE 110 can indicate the availability of the RLF report in an RRC re-establishment complete message. In response to this indication, base station 120A can request the RLF report by sending a UE information request message to UE 110. UE 110 can then send the RLF report to base station 120A in a UE information response message. In an example embodiment, the RLF report may include the time of occurrence of the radio link failure.

[0078] If the RLF report indicates a handover failure (e.g., a handover to MWAB failure), the RLF report can be enhanced using mobility information from MWAB node 120B for subsequent handover optimization. Enhancement can be performed at any of the source base station 120A (Option A), optimization entity 130 (Option B), and target MWAB node 120B (Option C). In Option A, base station 120A can send a request for mobility information to MWAB node 120B at 414. This request can indicate the time at which mobility information is requested. The indicated time can be the reconstruction time when UE 110's RRC connection is rebuilt, or the time when the radio link failure occurs. The request can also include information about UE 110, such as the C-RNTI in the source cell prior to handover, enabling MWAB node 120B to recognize that it approved UE 110's handover request during the handover preparation phase.

[0079] In response to the request, MWAB node 120B can determine mobility information at the indicated time. For example, MWAB node 120B can retrieve mobility information from historical data of mobility information that is periodically measured and updated at MWAB node 120B at the indicated time. Additionally, MWAB node 120B can also retrieve mobility information at the time it approves UE 110's handover request. Then, MWAB node 120B can send a response at 416 to base station 120A, which includes mobility information at the time when UE 110's RRC connection is re-established or when a radio link failure occurs, and mobility information at the time when MWAB node 120B approves UE 110's handover request.

[0080] At 418, base station 120A can use the mobility information received from MWAB node 120B to enhance the RLF report, and at 420, it sends the enhanced RLF report to optimization entity 130.

[0081] In Option B, base station 120A may send an RLF report to optimization entity 130 at 422. The RLF report may include the RLF occurrence time. Alternatively or additionally, base station 120A may include the UE connection re-establishment time recorded at 410, in the RLF report, in the message conveying the RLF report, or in a separate message. Optimization entity 130 may determine the target MWAB node 120B for the handover process based on the RLF report and send a request for mobility information to MWAB node 120B at 424. This request may indicate the time when the mobility information was requested. The indicated time may be the re-establishment time or the RLF occurrence time. The request may also include information about UE 110, such as the C-RNTI in the source cell prior to handover, enabling MWAB node 120B to recognize that it approved UE 110's handover request during the handover preparation phase.

[0082] In response to the request, MWAB node 120B can determine mobility information at the indicated time (i.e., the reconstruction time or RLF occurrence time) and mobility information at the time MWAB node 120B approves UE 110's handover request (i.e., the handover admission control time). MWAB node 120B can then send a response at 426 to optimization entity 130, which includes both the mobility information at the reconstruction time or RLF occurrence time and the mobility information at the handover admission control time. Optimization entity 130 can then utilize the received mobility information from MWAB node 120B at 428 to enhance the RLF report.

[0083] In option C, base station 120A may send an RLF report to the handover target RAN node (i.e., MWAB node 120B in the illustrated example) at 430. For example, base station 120A may send the RLF report via a failure indication message. The RLF report may include the RLF occurrence time. Alternatively or additionally, base station 120A may include the UE connection re-establishment time recorded at 410, in the RLF report, in the message conveying the RLF report, or in a separate message. MWAB node 120B may enhance the RLF report at 432 using mobility information, including both mobility information at the RLF occurrence time or re-establishment time and mobility information at the handover admission control time, and send the enhanced RLF report to optimization entity 130 at 434. In the example embodiment, MWAB node 120B may send the enhanced RLF report to source base station 120A, and then source base station 120A may send the enhanced RLF report to optimization entity 130.

[0084] Regardless of which option is applied, optimization entity 130 acquires an enhanced RLF report that includes mobility information of MWAB node 120B. Optimization entity 130 can then determine at point 436 whether the radio link failure / handover failure was caused by the mobility of MWAB node 120B. Optimization entity 130 can also use the failure reasons indicated in the RLF report to analyze the root cause of the handover failure.

[0085] If optimization entity 130 determines that the radio link failure / handover failure is caused by the mobility of MWAB node 120B, then optimization entity 130 may ignore the enhanced RLF report at 438. If optimization entity 130 determines that the radio link failure / handover failure is not caused by the mobility of MWAB node 120B, then optimization entity 130 may update performance indicators such as KPIs used for the handover process based on the enhanced RLF report at 438. Figure 4 In the example scenario shown, assume that UE 110's random access procedure toward the target MWAB node 120B fails, and then the RRC connection with the source base station 120A is rebuilt. The optimization entity 130 can determine from this fact that the handover procedure was initiated too early for UE 110, and therefore update the KPI for the premature handover to the MWAB at 438. The KPI will be used to optimize the handover procedure between two RAN nodes or between two specific cells. For example, if the premature handover to the MWAB indicator indicates the number of premature handover failures, the optimization entity 130 can optimize mobility parameters to initiate the handover to the MWAB node / cell later.

[0086] Figure 5 Another example optimization process 500 for premature handover to the MWAB is shown according to some example embodiments of this disclosure. Unlike process 400, where the handover failure occurs before UE 110 is handed over to the target MWAB node 120B, in process 500, the handover failure occurs shortly after UE 110 is successfully handed over to the target MWAB node 120B.

[0087] refer to Figure 5 Operations 202 to 218a can be performed as described above for handover preparation of UE 110; repeated descriptions of these operations are omitted here. Assume that UE 110 successfully receives the handover command at 218a and handover preparation is complete.

[0088] In response to the handover command, UE 110 can detach from the old / source cell at 502 and attempt to synchronize with the new / target cell provided by MWAB node 120B. At 504, UE 110 can acquire downlink (DL) and uplink (UL) synchronization with the target cell and initiate a random access procedure toward the target cell. Assuming the random access procedure is successfully executed, UE 110 moves its RRC connection from base station 120A to MWAB node 120B. At 506, UE 110 notifies MWAB node 120B of the handover procedure completion, for example, via an RRC reconfiguration complete message.

[0089] Suppose that UE 110 detects a Radio Link Failure (RLF) in the target cell at point 508 shortly after a successful handover and generates an RLF report. If the radio link failure is detected within a predetermined time period from the successful handover, UE 110 can indicate in the RLF report that the connection failure type is a handover failure (e.g., a handover to MWAB failure). The RLF report may include the Cell Global Identifier (CGI) of the failing cell (i.e., the target cell provided by MWAB node 120B) and the Cell Global Identifier of the previous cell (i.e., the source cell provided by base station 120A before the handover). The RLF report may also include, for example, UE 110's C-RNTI in the source cell before the handover and / or UE 110's C-RNTI in the target cell, multiple measurement reports prior to the radio link failure / handover, the cause of the failure, the time of the RLF occurrence, etc.

[0090] In response to a radio link failure, UE 110 can perform cell selection and initiate a reconstruction procedure to rebuild the RRC connection. Figure 5 In the example shown, assume UE 110 selects the source cell as the strongest cell and re-establishes its RRC connection with base station 120A at 510. Base station 120A can determine and record the time when UE 110's RRC connection was successfully re-established at 512. In the example embodiment, if the re-establishment request received from UE 110 indicates that the re-establishment was due to a handover failure (e.g., a failure to hand over to MWAB), or if base station 120A identifies that UE 110 experienced a handover failure (e.g., a failure to hand over to MWAB) based on other information included in the re-establishment request, then base station 120A can determine and record the time when UE 110's RRC connection was re-established.

[0091] When the RRC connection between UE 110 and base station 120A is re-established, base station 120A can retrieve the RLF report from UE 110 at 514.

[0092] If the RLF report indicates that the connection failure type is a handover failure (e.g., a handover to MWAB failure), the RLF report can be enhanced using mobility information from MWAB node 120B for subsequent handover optimization. Similar to process 400 discussed above, enhancements can be performed at any of the source base station 120A (Option A), optimization entity 130 (Option B), and target MWAB node 120B (Option C). In Option A, base station 120A can send a request for mobility information to target MWAB node 120B at point 516. Base station 120A can identify target MWAB node 120B based on the RLF report. The request can indicate the time at which mobility information is requested. The indicated time can be the reconstruction time when UE 110's RRC connection is rebuilt, or the time when the radio link failure occurs. The request can also include information about UE 110, such as the C-RNTI in the source cell or the C-RNTI in the target cell before the handover, enabling MWAB node 120B to recognize that it approved / allowed UE 110's handover request during the handover preparation phase.

[0093] In response to this request, MWAB node 120B can retrieve mobility information at the rebuild time or the RLF occurrence time. Additionally, MWAB node 120B can also retrieve mobility information determined when it approves / allows the handover request of UE 110. MWAB node 120B can send the mobility information to base station 120A at 518. At 520, base station 120A can use the received mobility information from MWAB node 120B to enhance the RLF report, and at 522, send the enhanced RLF report to optimization entity 130.

[0094] In Option B, base station 120A may send an RLF report to optimization entity 130 at point 524. The RLF report may include the RLF occurrence time. Alternatively or additionally, base station 120A may include the UE connection re-establishment time recorded at point 512, in the RLF report, in the message conveying the RLF report, or in a separate message. Optimization entity 130 may determine the target MWAB node 120B for the handover process based on the RLF report and send a request for mobility information to MWAB node 120B at point 526. This request may indicate the re-establishment time or RLF occurrence time at which the mobility information was requested. The request may also include information about UE 110, such as the C-RNTI in the source cell and / or the C-RNTI in the target cell before the handover, which may be indicated in the RLF report, enabling MWAB node 120B to recognize that it approved / allowed UE 110's handover request during the handover preparation phase.

[0095] In response to the request, MWAB node 120B can determine mobility information at the reconstruction time or the time of the RLF occurrence indicated in the request, as well as mobility information at the moment when MWAB node 120B approves / allows UE 110's handover request (i.e., at the handover admission control time). MWAB node 120B can then send a response at 528 to optimization entity 130, which includes both the mobility information at the reconstruction time or RLF occurrence time and the mobility information at the handover admission control time. Optimization entity 130 can then utilize the received mobility information from MWAB node 120B at 530 to enhance the RLF reporting.

[0096] In option C, base station 120A may send an RLF report to the handover target RAN node (i.e., MWAB node 120B in the illustrated example) at 532. For example, base station 120A may send the RLF report via a failure indication message. The RLF report may include the RLF occurrence time. Alternatively or additionally, base station 120A may include the UE connection re-establishment time recorded at 512, in the RLF report, in the message conveying the RLF report, or in a separate message. MWAB node 120B may enhance the RLF report at 534 using mobility information, including both mobility information at the RLF occurrence time or re-establishment time and mobility information at the handover admission control time, and send the enhanced RLF report to optimization entity 130 at 536. In the example embodiment, MWAB node 120B may send the enhanced RLF report to source base station 120A, and then source base station 120A may send the enhanced RLF report to optimization entity 130.

[0097] Regardless of the option applied, optimization entity 130 acquires an enhanced RLF report including mobility information for MWAB node 120B. Optimization entity 130 can then determine at 538 whether the radio link failure / handover failure was caused by the mobility of MWAB node 120B. Optimization entity 130 can also use the failure cause indicated in the RLF report to analyze the root cause of the handover failure. If the radio link failure / handover failure was caused by the mobility of MWAB node 120B, optimization entity 130 can ignore the enhanced RLF report at 540. If the radio link failure / handover failure was not caused by the mobility of MWAB node 120B, optimization entity 130 can update performance indicators such as KPIs used for the handover process based on the enhanced RLF report at 540. Figure 5In the example scenario shown, assume that UE 110 experiences a radio link failure shortly after its handover to target MWAB node 120B, and UE 110 rebuilds its RRC connection with source base station 120A. Optimization entity 130 can determine based on this fact that the handover process was initiated too early for UE 110, and therefore updates the KPI for the premature handover to MWAB at 540. The KPI will be used to optimize the handover process between two RAN nodes or between two specific cells. For example, if the premature handover to the MWAB indicator indicates the number of premature handover failures, optimization entity 130 can optimize mobility parameters to initiate the handover to the MWAB node / cell later.

[0098] Figure 6 An example optimization process 600 for faulty cell handover in MWAB is illustrated according to some example embodiments of this disclosure. Similar to process 400 discussed above, operations 202 to 218a and operations 402 to 406 can be performed, and repeated descriptions of these operations are omitted here. In response to a radio link failure detected at 406, UE 110 can perform cell selection and initiate a reconstruction procedure to rebuild the RRC connection. Figure 6 In the example shown, it is assumed that UE 110 selects the cell provided by a third base station (e.g., gNB) 120C as the strongest cell and re-establishes the RRC connection with the third base station 120C at 602. The third base station 120C can determine and record the time when the RRC connection of UE 110 is re-established at 604. In the example embodiment, if the re-establishment request received from UE 110 indicates that the reason for the re-establishment is a handover failure (e.g., handover to MWAB failure), or if the third base station 120C identifies that UE 110 has experienced a handover failure (e.g., handover to MWAB failure) based on other information included in the re-establishment request, then the third base station 120C can determine and record the time when the RRC connection of UE 110 is re-established.

[0099] When the RRC connection between UE 110 and third base station 120C is re-established, third base station 120C can retrieve the RLF report from UE 110 at position 606. For example, UE 110 can indicate the availability of the RLF report in an RRC re-establishment complete message. In response to this indication, third base station 120C can request the RLF report by sending a UE information request message to UE 110. UE 110 can then send the RLF report to third base station 120C in a UE information response message. In an example embodiment, the RLF report may include the time of occurrence of the radio link failure.

[0100] If the RLF report indicates a handover failure (e.g., a handover to MWAB failure), the RLF report can be enhanced using mobility information from MWAB node 120B for subsequent handover optimization. Enhancement can be performed at any of the third base station 120C (Option A), source base station 120A (Option B), target MWAB node 120B (Option C), and optimization entity 130 (Option D). In Option A, the third base station 120C can send a request for mobility information to the target MWAB node 120B at point 608. The third base station 120C can identify the target MWAB node 120B based on the measurement report included in the RLF report. The request can indicate the UE connection reconstruction time or the RLF occurrence time. The request can also include information about UE 110, such as the C-RNTI in the source cell prior to handover, enabling MWAB node 120B to recognize that it approved UE 110's handover request during the handover preparation phase.

[0101] In response to this request, MWAB node 120B can determine mobility information at the UE connection re-establishment time or the RLF occurrence time. Additionally, MWAB node 120B can also determine mobility information at the moment it approves / allows the handover request of UE 110. Then, MWAB node 120B can send a response at 610 to the third base station 120C, which includes mobility information at the UE connection re-establishment time or the RLF occurrence time and mobility information at the handover admission control time (i.e., the handover preparation phase).

[0102] The third base station 120C can use the mobility information received from the MWAB node 120B at 612 to enhance the RLF report, and send the enhanced RLF report to the optimization entity 130 at 614.

[0103] In Option B, the third base station 120C may send an RLF report to the source base station 120A at 616. The third base station 120C may identify the source base station 120A based on the RLF report. The RLF report may include the RLF occurrence time. Alternatively or additionally, the third base station 120C may include the UE connection re-establishment time recorded at 604, in the RLF report, in the message conveying the RLF report, or in a separate message. The source base station 120A may determine the target MWAB node 120B for the handover process based on the RLF report and send a request for mobility information to the MWAB node 120B at 618. This request may indicate the UE connection re-establishment time or the RLF occurrence time for which the mobility information is requested. The request may also include information about UE 110, such as the C-RNTI in the source cell prior to the handover, enabling the MWAB node 120B to identify that it approved / allowed the handover request of UE 110 during the handover preparation phase.

[0104] In response to this request, MWAB node 120B can determine mobility information at the UE connection re-establishment time or the RLF occurrence time. Additionally, MWAB node 120B can also determine mobility information at the moment it approves / allows the handover request of UE 110. Then, at 620, MWAB node 120B can send a response to source base station 120A, which includes mobility information at the UE connection re-establishment time or the RLF occurrence time and mobility information at the handover admission control time (i.e., the handover preparation phase).

[0105] The source base station 120A can use the mobility information received from the MWAB node 120B at 622 to enhance the RLF report, and send the enhanced RLF report to the optimization entity 130 at 624.

[0106] In option C, the third base station 120C may send an RLF report to the target MWAB node 120B at 626. The third base station 120C may identify the target MWAB node 120B based on the measurement report included in the RLF report. The RLF report may include the RLF occurrence time. Alternatively or additionally, the third base station 120C may include the UE connection re-establishment time recorded at 604, in the RLF report, in the message conveying the RLF report, or in a separate message. The MWAB node 120B may enhance the RLF report at 628 using mobility information, including both mobility information at the RLF occurrence time or re-establishment time and mobility information at the handover admission control time, and send the enhanced RLF report to the optimization entity 130 at 630. In an example embodiment, the MWAB node 120B may send the enhanced RLF report to the source base station 120A, and then the source base station 120A may send the enhanced RLF report to the optimization entity 130.

[0107] In option D, the third base station 120C may send an RLF report to the optimization entity 130 at 632. The RLF report may include the RLF occurrence time. Alternatively or additionally, the third base station 120C may include the UE connection re-establishment time recorded at 604, in the RLF report, in the message conveying the RLF report, or in a separate message. The optimization entity 130 may identify the target MWAB node 120B of the handover process based on the RLF report and send a request for mobility information to the MWAB node 120B at 634. This request may indicate the re-establishment time or RLF occurrence time at which the mobility information was requested. The request may also include information about the UE 110, such as the C-RNTI in the source cell prior to the handover process, enabling the MWAB node 120B to recognize that it approved / allowed the handover request of the UE 110 during the handover preparation phase.

[0108] In response to the request, MWAB node 120B can determine mobility information at the reconstruction time or the time of the RLF occurrence indicated in the request, as well as mobility information at the moment when MWAB node 120B approves / allows UE 110's handover request (i.e., at the handover admission control time). MWAB node 120B can then send a response at 636 to optimization entity 130, which includes both the mobility information at the reconstruction time or RLF occurrence time and the mobility information at the handover admission control time. Optimization entity 130 can then utilize the received mobility information from MWAB node 120B at 638 to enhance the RLF reporting.

[0109] Regardless of which option is applied, optimization entity 130 acquires an enhanced RLF report that includes mobility information of MWAB node 120B. Optimization entity 130 can then determine at 640 whether the radio link failure / handover failure was caused by the mobility of MWAB node 120B. Optimization entity 130 can also use the failure reasons indicated in the RLF report to analyze the root cause of the handover failure.

[0110] If optimization entity 130 determines that the radio link failure / handover failure is caused by the mobility of MWAB node 120B, then optimization entity 130 may ignore the enhanced RLF report at 642. If optimization entity 130 determines that the radio link failure / handover failure is not caused by the mobility of MWAB node 120B, then optimization entity 130 may update performance indicators such as KPIs used for the handover process based on the enhanced RLF report at 642. Figure 6 In the example scenario shown, assume that UE 110's random access procedure toward target MWAB node 120B fails, and then an RRC connection with the third base station 120C is rebuilt. The optimization entity 130 can determine based on this fact that a handover procedure for UE 110 was initiated to the wrong cell, and therefore update the KPI for the wrong cell handover to the MWAB at 642. The KPI will be used to optimize the handover procedure between two RAN nodes or between two specific cells. For example, if the wrong cell handover to the MWAB indicator indicates the number of failed wrong cell handovers to the MWAB, the optimization entity 130 can optimize mobility parameters to reduce the probability of a handover from base station 120A to MWAB node 120B and increase the probability of a handover from base station 120A to the third base station 120C.

[0111] Figure 7 Another example optimization process 700 for erroneous cell handover in MWAB according to some example embodiments of this disclosure is shown. Similar to process 500 discussed above, operations 202 to 218a and operations 502 to 508 can be performed, and repeated descriptions of these operations are omitted here. In response to a radio link failure detected at 508 shortly after a successful handover to MWAB node 120B, UE 110 can perform cell selection and initiate a reconstruction procedure to rebuild the RRC connection. Figure 7In the example shown, it is assumed that UE 110 selects the cell provided by a third base station (e.g., gNB) 120C as the strongest cell and re-establishes the RRC connection with the third base station 120C at 702. The third base station 120C can determine and record the time when the RRC connection of UE 110 was re-established at 704. In the example embodiment, if the re-establishment request received from UE 110 indicates that the reason for the re-establishment is a handover failure (e.g., handover to MWAB failure), or if the third base station 120C identifies, based on other information included in the re-establishment request, that UE 110 experienced a radio link failure shortly after the handover (e.g., within a predetermined period of time from the handover), then the third base station 120C can determine and record the time when the RRC connection of UE 110 was re-established.

[0112] When the RRC connection between UE 110 and third base station 120C is re-established, third base station 120C can retrieve the RLF report from UE 110 at point 706. For example, UE 110 can indicate the availability of the RLF report in an RRC re-establishment complete message. In response to this indication, third base station 120C can request the RLF report by sending a UE information request message to UE 110. UE 110 can then send the RLF report to third base station 120C in a UE information response message. In an example embodiment, the RLF report may include the time of occurrence of the radio link failure.

[0113] If the RLF report indicates a handover failure (e.g., a handover to MWAB failure), the RLF report can be enhanced using mobility information from MWAB node 120B for subsequent handover optimization. Enhancement can be performed at any of the third base station 120C (Option A), source base station 120A (Option B), target MWAB node 120B (Option C), and optimization entity 130 (Option D). In Option A, the third base station 120C can send a request for mobility information to the target MWAB node 120B at point 708. The third base station 120C can identify the target MWAB node 120B based on the measurement report included in the RLF report. This request can indicate the UE connection re-establishment time or the RLF occurrence time. The request can also include information about UE 110, such as the C-RNTI in the source cell and / or the C-RNTI in the target cell before the handover, enabling MWAB node 120B to recognize that it approved / allowed UE 110's handover request during the handover preparation phase.

[0114] In response to this request, MWAB node 120B can determine mobility information at the UE connection re-establishment time or the RLF occurrence time. Additionally, MWAB node 120B can also determine mobility information at the moment it approves / allows UE 110's handover request. Then, MWAB node 120B can send a response at 710 to the third base station 120C, which includes mobility information at the UE connection re-establishment time or the RLF occurrence time and mobility information at the handover admission control time (i.e., the handover preparation phase).

[0115] The third base station 120C can enhance the RLF report at 712 using the received mobility information from the MWAB node 120B, and send the enhanced RLF report to the optimization entity 130 at 714. In an example embodiment, the third base station 120C can send the enhanced RLF report to the source base station 120A, and the source base station 120A can forward the enhanced RLF report to the optimization entity 130.

[0116] In Option B, the third base station 120C may send an RLF report to the source base station 120A at point 716. The third base station 120C can identify the source base station 120A based on the RLF report. For example, the RLF report may include the Cell Global Identifier (CGI) of the failed cell (i.e., the target cell provided by MWAB node 120B) and the Cell Global Identifier of the previous cell (i.e., the source cell provided by base station 120A before the handover). The RLF report may also include the RLF occurrence time. Alternatively or additionally, the third base station 120C may include the UE connection re-establishment time recorded at point 704, in the RLF report, in the message conveying the RLF report, or in a separate message. Upon receiving the RLF report, the source base station 120A can determine the target MWAB node 120B for the handover process based on the RLF report and send a request for mobility information to MWAB node 120B at point 718. This request may indicate the UE connection re-establishment time or the RLF occurrence time for which the mobility information is requested. The request may also include information about UE 110, such as the C-RNTI in the source cell and / or the C-RNTI in the target cell prior to the handover, enabling MWAB node 120B to recognize that it approved / allowed UE 110's handover request during the handover preparation phase.

[0117] In response to this request, MWAB node 120B can determine mobility information at the UE connection re-establishment time or the RLF occurrence time. Additionally, MWAB node 120B can also determine mobility information at the moment it approves / allows the handover request of UE 110. Then, at 720, MWAB node 120B can send a response to source base station 120A, which includes mobility information at the UE connection re-establishment time or the RLF occurrence time and mobility information at the handover admission control time (i.e., the handover preparation phase).

[0118] The source base station 120A can use the mobility information received from the MWAB node 120B at 722 to enhance the RLF report, and send the enhanced RLF report to the optimization entity 130 at 724.

[0119] In option C, the third base station 120C may send an RLF report to the target MWAB node 120B at 726. The third base station 120C may identify the target MWAB node 120B based on the RLF report. The RLF report may include the RLF occurrence time. Alternatively or additionally, the third base station 120C may include the UE connection re-establishment time recorded at 704, in the RLF report, in the message conveying the RLF report, or in a separate message. The MWAB node 120B may enhance the RLF report at 728 using mobility information, including both mobility information at the RLF occurrence time or re-establishment time and mobility information at the handover admission control time, and send the enhanced RLF report to the optimization entity 130 at 730. In an example embodiment, the MWAB node 120B may send the enhanced RLF report to the source base station 120A, and then the source base station 120A may forward the enhanced RLF report to the optimization entity 130.

[0120] In option D, the third base station 120C may send an RLF report to the optimization entity 130 at 732. The RLF report may include the RLF occurrence time. Alternatively or additionally, the third base station 120C may include the UE connection re-establishment time recorded at 704, in the RLF report, in the message conveying the RLF report, or in a separate message. The optimization entity 130 may identify the target MWAB node 120B of the handover process based on the RLF report and send a request for mobility information to the MWAB node 120B at 734. The request may indicate the re-establishment time or RLF occurrence time at which the mobility information was requested. The request may also include information about the UE 110, such as the C-RNTI in the source cell and / or the C-RNTI in the target cell before the handover process, enabling the MWAB node 120B to recognize that it approved / allowed the handover request of the UE 110 during the handover preparation phase.

[0121] In response to the request, MWAB node 120B can determine mobility information at the reconstruction time or the time of the RLF occurrence indicated in the request, as well as mobility information at the moment when MWAB node 120B approves / allows UE 110's handover request (i.e., at the handover admission control time). MWAB node 120B can then send a response at 736 to optimization entity 130, which includes both the mobility information at the reconstruction time or RLF occurrence time and the mobility information at the handover admission control time. Optimization entity 130 can then utilize the received mobility information from MWAB node 120B at 738 to enhance the RLF reporting.

[0122] Regardless of which option is applied, optimization entity 130 acquires an enhanced RLF report that includes mobility information of MWAB node 120B. Optimization entity 130 can then determine at 740 whether the radio link failure / handover failure was caused by the mobility of MWAB node 120B. Optimization entity 130 can also use the failure reasons indicated in the RLF report to analyze the root cause of the handover failure.

[0123] If optimization entity 130 determines that the radio link failure / handover failure is caused by the mobility of MWAB node 120B, then optimization entity 130 may ignore the enhanced RLF report at 742. If optimization entity 130 determines that the radio link failure / handover failure is not caused by the mobility of MWAB node 120B, then optimization entity 130 may update performance indicators such as KPIs used for the handover process based on the enhanced RLF report at 742. Figure 7 In the example scenario shown, assume that UE 110 experienced a radio link failure shortly after handing over to target MWAB node 120B, and it re-established a connection with the third base station 120CRRC. The optimization entity 130 can determine based on this fact that the handover process was initiated for UE 110 to the wrong cell, and therefore update the KPI for the wrong cell handover to the MWAB at 742. The KPI will be used to optimize the handover process between two RAN nodes or between two specific cells. For example, if the wrong cell handover to the MWAB indicator indicates the number of failed wrong cell handovers to the MWAB, the optimization entity 130 can optimize mobility parameters to reduce the probability of handover from base station 120A to MWAB node 120B and increase the probability of handover from base station 120A to the third base station 120C.

[0124] Figure 8An example optimization process 800 for near-failure handover to a MWAB according to some example embodiments of this disclosure is illustrated. Similar to process 500 discussed above, operations 202 to 218a and operations 502 to 506 can be performed; for convenience, repeated descriptions of these operations are omitted here. UE 110 successfully hands over from source base station 120A to target MWAB node 120B, and it does not experience radio link failure during or after the handover process. In the example embodiment, target MWAB node 120B may record the moment when UE 110 successfully hands over to target MWAB node 120B at 802.

[0125] In procedure 800, it is assumed that UE 110 detects a proximity failure during handover. For example, if timer T310 or T312 of UE 110 exceeds a threshold configured by the source base station 120A, or timer T304 of UE 110 exceeds a threshold configured by the target MWAB node 120B, UE 110 can determine that it has experienced a proximity failure. In response to the proximity failure, UE 110 can generate a Successful Handover Report (SHR) or a Successful PSCell Change Report (SPR) at 804. If a proximity failure is detected during a normal handover procedure, UE 110 will generate an SHR report. If UE 110 is operating in dual-connectivity mode and detects a proximity failure during a handover procedure performed for a PSCell change, i.e., the target cell provided by MWAB node 120B is used as the new PSCell for UE 110, UE 110 will generate an SPR report. The SHR or SPR report may include the source cell ID and target cell ID of the handover, the C-RNTI of the target cell, the latest radio measurement results, the time of occurrence of the proximity failure, etc. In an example embodiment, the SHR or SPR report may also include a reason that is triggered to generate the SHR or SPR report. For example, the reason may indicate that timer T310 has exceeded a threshold, timer T312 has exceeded a threshold, or timer T304 has exceeded a threshold. The reason for near failure can be used at optimization entity 130 to switch to root cause analysis for near failure.

[0126] At position 806, MWAB node 120B can retrieve an SHR or SPR report from UE 110. For example, UE 110 can indicate the availability of an SHR or SPR report in a handover completion message (i.e., an RRC reconfiguration completion message) at position 506. In response to this indication, MWAB node 120B can request an SHR or SPR report by sending a UE Information Request message to UE 110. UE 110 can then send the SHR or SPR report to MWAB node 120B in a UE Information Response message.

[0127] In response to an SHR or SPR report, MWAB node 120B can determine and record at 808: mobility information near the time of failure indicated in the SHR or SPR report, or mobility information upon successful execution of the handover procedure recorded at 802. At 810, MWAB node 120B can enhance the received SHR or SPR report based on the mobility information determined at 214 (i.e., mobility information when the UE 110's handover is allowed / accepted / approved during the handover preparation phase) and the mobility information determined at 808 (i.e., mobility information near the time of failure or handover completion). MWAB node 120B can add mobility information to the SHR or SPR report. Alternatively or additionally, MWAB node 120B can process the mobility information to add statistical information to the SHR or SPR report. For example, MWAB node 120B can calculate the average or maximum speed, and / or the distance traveled between the handover admission control time (“initial” time) and the time close to failure or handover completion time (“final” time), and include such calculated data in the SHR or SPR report.

[0128] Then, MWAB node 120B can send an enhanced SHR or SPR report to optimization entity 130 at 812. In another example embodiment, MWAB node 120B can send an enhanced SHR or SPR report to source base station 120A at 814. Then, source base station 120A can forward the enhanced SHR or SPR report to optimization entity 130 at 816.

[0129] Upon receiving an enhanced SHR or SPR report, optimization entity 130 can determine at point 818 whether the handover approach failure is caused by the mobility of MWAB node 120B based on mobility information. A set of rules and relevant thresholds can be used at optimization entity 130 to determine whether the handover approach failure is caused by the mobility of MWAB node 120B. For example, if mobility information indicates that the position of MWAB node 120B at the “final” time differs significantly from its position at the “initial” time, then MWAB node 120B has traveled a long distance during the time period from the “initial” time to the “final” time, and / or MWAB node 120B has a high speed at the “initial” time or a high average / maximum speed during the time period from the “initial” time to the “final” time, then optimization entity 130 can determine that the handover approach failure is caused by the mobility of MWAB node 120B, rather than by the current mobility parameters. If the mobility information does not indicate significant movement of MWAB node 120B, then optimization entity 130 can determine that the near handover failure is caused by inappropriate mobility parameters currently applied, rather than by the mobility of MWAB node 120B. It should be understood that the rules and relevant thresholds applied in the case of near handover failure may differ from those applied in the case of radio link failure / handover failure discussed above.

[0130] If optimization entity 130 determines that the near handover failure is caused by the mobility of MWAB node 120B, then optimization entity 130 can ignore the enhanced SHR / SPR report at 820, because the currently applied mobility parameters may be appropriate. If optimization entity 130 determines that the near handover failure is not caused by the mobility of MWAB node 120B, then the currently applied mobility parameters may be incorrect and need to be optimized. Then, optimization entity 130 can update performance indicators for the handover process, such as key performance indicators (KPIs), based on the enhanced SHR / SPR report at 820. Figure 8In the example scenario shown, UE 110 successfully hands over to MWAB node 120B, and a near failure is detected during the handover process. Therefore, depending on whether an SHR or SPR report is received, optimization entity 130 can update the KPI for near failure handover to MWAB, or the KPI for near failure PSCell change to MWAB. It should be understood that optimization entity 130 is capable of collecting SHR / SPR reports and other reports from multiple UEs and RAN nodes, and updating KPIs based on these reports. The KPIs will be used to optimize the handover process between two RAN nodes or between two specific cells. For example, if a near failure handover to the MWAB indicator or a near failure PSCell change to the MWAB indicator indicates that multiple near failure handovers have occurred, optimization entity 130 can optimize mobility parameters to remove near failures and ensure a successful and reliable handover to the MWAB node / cell.

[0131] Figure 9 A method 900 according to an example embodiment of the present disclosure is illustrated. Method 900 can be performed at a UE (e.g., UE 110 discussed above). In the example embodiment, an apparatus can be implemented as at least part of the UE 110 to perform method 900. The apparatus can be implemented by various components for performing functions corresponding to the steps of method 900. These various components can include hardware, firmware, software, or any combination thereof.

[0132] Reference Figure 9 Method 900 may include at 910 detecting a failure or near failure associated with a handover process to a target network node implemented as a Mobile Radio Access Backhaul (MWAB) node, and at 920 sending a report to the network node including the time of occurrence of the failure or near failure.

[0133] This report can indicate detected failures or near-failures, which may include radio link failures (RLFs) at the source cell before the handover process is performed, radio link failures during the handover process, radio link failures at the target cell within a predetermined time period after the handover process, or near-failures during the handover process. The report may include radio link failure reports, successful handover reports, successful primary / secondary cell change reports, self-organizing network reports, or minimized drive test reports.

[0134] In an example embodiment, the report may also include the cause of failure or near failure, which may include at least one of the following: measurement report conditions are not met; measurement report is lost due to poor channel conditions; no handover command is received; or timers such as T310, T312, and T304 exceed their thresholds.

[0135] The network node to which the report is sent can be the source network node used for the handover process, the target network node used for the handover process (i.e., the MWAB node), or a third network node other than the source and target network nodes. In the example, if UE 110 experiences a radio link failure during or shortly after the handover process, and UE 110 rebuilds its RRC connection with the source, target, or third network node, UE 110 can send a report to the connected source, target, or third network node. In another example, if the handover process is successful and UE 110 detects a near-failure during the handover process, UE 110 can send a report to the target network node to which it is switched.

[0136] In some example embodiments, method 900 may further include receiving, during the handover process, an indication that the target network node is the MWAB node in the handover command, or receiving an indication that the target network node is the MWAB node from the source network node (not shown). For example, the target network node (i.e., the MWAB node) may indicate in the handover command that the target network node for the handover process is the MWAB node, or the source network node may indicate in the message conveying the handover command or in a separate message that the target network node for the handover process is the MWAB node. In response to this indication, UE 110 may include the time of occurrence of failure or near failure in the report.

[0137] Figure 10 A method 1000 according to an example embodiment of the present disclosure is illustrated. Method 1000 can be performed at a RAN node (e.g., the source base station 120A or the third base station 120C discussed above). In the example embodiment, an apparatus can be implemented as at least part of the RAN node to perform method 1000. The apparatus can be implemented by various components for performing functions corresponding to the steps of method 1000. These various components can include hardware, firmware, software, or any combination thereof.

[0138] Reference Figure 10 Method 1000 may include receiving at 1010 a report indicating a failure associated with a handover process for the UE to a target network node implemented as a Mobile Radio Access Backhaul (MWAB) node, and at 1020 sending a request for mobility information to the target network node. This request may indicate the first moment that mobility information of the target network node (i.e., the MWAB node) is requested.

[0139] In an example embodiment, the RAN node (e.g., source base station 120A or third base station 120C) can receive reports from the UE. For example, the UE can experience a failure associated with a handover procedure and rebuild its connection with the RAN node. The UE can then send a report to the RAN node. In another example embodiment, the RAN node is source base station 120A, and the RAN node receives reports from third base station 120C. For example, the UE can experience a failure associated with a handover procedure and rebuild its connection with third base station 120C. When the connection is rebuilt, the UE can send a report to third base station 120C, and third base station 120C can forward the report to source base station 120A.

[0140] In an example embodiment, the first moment indicated in the mobility information request may be received in a report indicating a failure associated with the handover process. For example, the UE may include the time of the failure as the first moment in the report. In another example embodiment, the first moment may be determined at the RAN node. For example, when the UE re-establishes its connection with the RAN node after a failure associated with the handover process, the RAN node may determine the re-establishment time as the first moment. In yet another example embodiment, when the UE re-establishes its connection with a third base station 120C and the third base station 120C forwards a failure report from the UE to the RAN node (i.e., the source base station 120A), the first moment may be determined at the third base station 120C as the re-establishment time. The third base station 120C may indicate the determined first moment in the failure report, in a message conveying the failure report (e.g., a failure indication message), or in a separate message to the source base station 120A.

[0141] In an example embodiment, a report indicating a failure associated with the handover process may also indicate the cause of the failure. For example, the cause of failure may include measurement report conditions not being met, measurement reports being lost due to poor channel conditions, or a handover command not being received.

[0142] like Figure 10 As shown, method 1000 may further include: at 1030, receiving mobility information at a first time and mobility information at a second time from the target network node; at 1040, enhancing the report based on the mobility information received from the target network node; and at 1050, sending the enhanced report to an optimization entity. The second time may refer to the time when the target network node allows the UE to hand over to the target network node during the handover preparation phase.

[0143] In an example embodiment, mobility information received from a target network node may include one or more of the following: the target network node's location, speed, distance traveled, or current time. The report can be enhanced by including mobility information from a first time point and a second time point, and / or by including statistical information derived from the mobility information from the first and second time points.

[0144] Figure 11 A method 1100 according to an example embodiment of the present disclosure is illustrated. Method 1100 can be performed at a Mobile Radio Access Backhaul (MWAB) node (e.g., MWAB node 120B discussed above), which serves as the target network node for the UE during handover. In the example embodiment, an apparatus can be implemented as at least part of the MWAB node to perform method 1100. The apparatus can be implemented by various components for performing functions corresponding to the steps of method 1100. These components can include hardware, firmware, software, or any combination thereof.

[0145] refer to Figure 11 Method 1100 may include: establishing a connection with the UE at 1110 after the handover procedure via a handover or reconstruction procedure; receiving a report of failure or near failure associated with the handover procedure from the UE at 1120; enhancing the report at 1130 based on mobility information at a first time and a second time; and sending the enhanced report to an optimization entity at 1140. The first time may refer to the time when the failure or near failure associated with the handover procedure occurs (which may be indicated in the report), the time when the handover procedure is successfully executed (e.g., the time when a handover completion message is received), or the time when the reconstruction procedure is executed (e.g., the time when a reconstruction completion message is received). The second time may refer to the time when the handover request for the UE is approved / allowed during the handover preparation phase.

[0146] In an example embodiment, mobility information may include one or more of the following: the location of the target network node, the speed of the target network node, the distance traveled by the target network node, or the current time of the target network node. The MWAB node may periodically measure and store mobility information. Then, at 1130, the MWAB node may retrieve mobility information from historical data using a first time and a second time, and utilize the retrieved mobility information to enhance the report. The report may be enhanced by including mobility information from the first and second time times, and / or by including statistical information derived from the mobility information. The report may indicate a radio link failure at the source cell prior to the handover process being performed, or a near failure during the handover process.

[0147] Figure 12A method 1200 according to an example embodiment of the present disclosure is illustrated. Method 1200 can be executed at a Mobile Radio Access Backhaul (MWAB) node (e.g., MWAB node 120B discussed above), which serves as the target network node for the UE during handover. In the example embodiment, an apparatus can be implemented as at least part of the MWAB node to execute method 1200. The apparatus can be implemented by various components for performing functions corresponding to the steps of method 1200. These components can include hardware, firmware, software, or any combination thereof.

[0148] Reference Figure 12 Method 1200 may include: re-establishing the connection with the UE at 1210 via a reconstruction process; receiving at 1220 a report indicating a failure associated with the handover process and a second moment in which the failure occurred; at 1230 enhancing the report using mobility information at the first moment in which the UE's connection was re-established and at the second moment in which the failure occurred; and at 1240 sending the enhanced report to an optimization entity.

[0149] In an example embodiment, the report received from the UE may also indicate the reason for a failure associated with the handover process. Reasons for failure may include: measurement report conditions not being met, measurement reports being lost due to poor channel conditions, or a handover command not being received.

[0150] Figure 13 A method 1300 according to an example embodiment of this disclosure is illustrated. Method 1300 can be performed at a Mobile Radio Access Backhaul (MWAB) node (e.g., MWAB node 120B discussed above), which serves as the target network node for the UE during handover. In the example embodiment, an apparatus can be implemented as at least part of the MWAB node to perform method 1300. The apparatus can be implemented by various components for performing functions corresponding to the steps of method 1300. These components can include hardware, firmware, software, or any combination thereof.

[0151] Reference Figure 13 Method 1300 may include receiving a request for mobility information at a first moment from a network node at 1310, and sending a response containing mobility information at the first moment and the second moment to the network node at 1320.

[0152] In an example embodiment, the first moment may refer to the time when a failure associated with the handover process occurs, or the time when a reconstruction process is performed for the UE after a failure associated with the handover process. The second moment may refer to the time during the handover preparation phase when the UE's request to handover from the source network node to the MWAB node is permitted / approved.

[0153] In some example embodiments, the network node may be the source network node for the UE during the handover process, or a third network node other than the source network node and the target network node, to which the UE connects or optimizes the entity through a reconstruction process after a failure associated with the handover process.

[0154] Figure 14 A method 1400 according to an example embodiment of the present disclosure is illustrated. Method 1400 can be performed at an optimization entity (e.g., optimization entity 130 discussed above) configured to optimize mobility parameters. The optimization entity may include, for example, a random access network (RAN) node, a core network node, a RAN intelligent controller (RIC), an operations management and maintenance (OAM) entity, etc. In the example embodiment, an apparatus may be implemented as at least a part of the optimization entity to perform method 1400. The apparatus may be implemented by various components for performing functions corresponding to the steps of method 1400. These various components may include hardware, firmware, software, or any combination thereof.

[0155] Reference Figure 14 Method 1400 may include: at 1410, receiving a report of failure or near failure associated with a handover process of the UE to a target network node implemented as a Mobile Radio Access Backhaul (MWAB) node, the report containing mobility information of the target network node; and at 1420, determining, based on the mobility information of the target network node, whether the failure or near failure is caused by the mobility of the target network node.

[0156] If it is determined that the failure or near failure is caused by the mobility of the target network node (i.e., the MWAB node), method 1400 may further include ignoring the failure or near failure report associated with the handover process at 1430. If it is determined that the failure or near failure is not caused by the mobility of the target network node (i.e., the MWAB node), method 1400 may further include updating, at 1440, performance indicators (such as critical performance indicators) for the handover process based on the failure or near failure report associated with the handover process. Critical performance indicators may include at least one of the following: for example, premature handover to the MWAB indicator, late handover to the MWAB indicator, erroneous cell change to the MWAB indicator, near failure handover to the MWAB indicator, or near failure PSCell change to the MWAB indicator.

[0157] In an example embodiment, mobility information included in a failure or near-failure report may include, for example, mobility information of the target network node during handover preparation (e.g., the moment when the UE's handover request is executed / approved during the handover preparation phase and / or the moment when the UE experiences a radio link failure during the handover preparation phase), mobility information of the target network node during handover execution (e.g., the moment when the UE experiences a radio link failure during the handover execution phase), mobility information of the target network node within a time period after the handover process (e.g., the moment when the UE experiences a radio link failure shortly after the handover process), and / or mobility information of the target network node during the reconstruction process after the handover process (e.g., the moment when the UE's connection is successfully re-established).

[0158] In an example embodiment, the failure or near-failure report may also indicate the cause of the failure or near-failure associated with the handover process. Causes of failure or near-failure may include, for example, measurement reporting conditions not being met, measurement reports being lost due to poor channel conditions, no handover command being received, and / or timers such as T310, T312, T304 exceeding a threshold. The optimization entity may further determine whether the failure or near-failure is caused by the mobility of the target network node based on the cause of the failure or near-failure.

[0159] Figure 15 A method 1500 according to an example embodiment of the present disclosure is illustrated. Method 1500 can be performed at an optimization entity (e.g., optimization entity 130 discussed above) configured to optimize mobility parameters. The optimization entity may include, for example, a random access network (RAN) node, a core network node, a RAN intelligent controller (RIC), an operations management and maintenance (OAM) entity, etc. In the example embodiment, an apparatus may be implemented as at least a part of the optimization entity to perform method 1500. The apparatus may be implemented by various components for performing functions corresponding to the steps of method 1500. These various components may include hardware, firmware, software, or any combination thereof.

[0160] refer to Figure 15Method 1500 may include receiving at 1510 a report of failure or near failure associated with a handover process for a UE to a target network node implemented as a Mobile Radio Access Backhaul (MWAB) node, the report indicating that at a first moment when the failure or near failure associated with the handover process occurs, or at a first moment when a reconstruction process is performed after the failure associated with the handover process, a request for mobility information at a first moment is sent to the target network node at 1520, receiving the mobility information at the first moment and the mobility information at a second moment from the target network node at 1530, the second moment referring to the time during which the target network node allows the UE to handover during the handover process, and determining at 1540 whether the failure or near failure is caused by the mobility of the target network node based on the mobility information of the target network node at the first moment and the second moment.

[0161] If it is determined that the failure or near failure is caused by the mobility of the target network node (i.e., the MWAB node), method 1500 may further include ignoring the failure or near failure report associated with the handover process at 1550. If it is determined that the failure or near failure is not caused by the mobility of the target network node (i.e., the MWAB node), method 1500 may further include updating, at 1560, performance indicators (such as critical performance indicators) for the handover process based on the failure or near failure report associated with the handover process. Critical performance indicators may include at least one of the following: for example, premature handover to the MWAB indicator, late handover to the MWAB indicator, erroneous cell change to the MWAB indicator, near failure handover to the MWAB indicator, or near failure PSCell change to the MWAB indicator.

[0162] In an example embodiment, method 1500 may further include enhancing the report (not shown) based on mobility information of the target network node at a first time and a second time. The optimization entity may utilize the mobility information and / or statistical information derived from the mobility information to enhance the report.

[0163] In an example embodiment, the failure or near-failure report may also indicate the cause of the failure or near-failure associated with the handover process. Causes of failure or near-failure may include, for example, measurement reporting conditions not being met, measurement reports being lost due to poor channel conditions, no handover command being received, and / or timers such as T310, T312, T304 exceeding a threshold. The optimization entity may further determine whether the failure or near-failure is caused by the mobility of the target network node based on the cause of the failure or near-failure.

[0164] Figure 16AAn apparatus 1610 according to an example embodiment of the present disclosure is shown. The apparatus 1610 may be implemented to include or form at least a portion of a UE (such as UE 110 discussed above). Figure 16A As shown, device 1610 may include one or more processors 1611, one or more memories 1612, and one or more transceivers 1613 interconnected via one or more buses 1614. The one or more buses 1614 may be address, data, or control buses and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, optical fiber, optics, or other optical communication equipment. Each of the one or more transceivers 1613 may include a receiver and a transmitter connected to one or more antennas 1616. Device 1610 may wirelessly communicate with network devices (e.g., base stations) via the one or more antennas 1616. The one or more memories 1612 may include instructions 1615, which, when executed by the one or more processors 1611, may cause device 1610 to perform operations related to the aforementioned UE 110.

[0165] Figure 16B An apparatus 1620 according to an example embodiment of the present disclosure is shown. The apparatus 1620 may be implemented to include or form at least a portion of a RAN node (such as the source base station 120A, target MWAB node 120B, or third base station 120C discussed above). Figure 16B As shown, device 1620 may include one or more processors 1621, one or more memories 1622, one or more transceivers 1623, and one or more network interfaces 1627 interconnected via one or more buses 1624. The one or more buses 1624 may be address, data, or control buses and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optic cable, optics, or other optical communication device. Each of the one or more transceivers 1623 may include a receiver and a transmitter connected to one or more antennas 1626. Device 1620 may wirelessly communicate with a UE and / or other network nodes or functions via the one or more antennas 1626. The one or more network interfaces 1627 may provide wired and / or wireless communication links through which device 1620 may communicate with other UEs and / or network nodes or functions. For example, device 1620 may communicate with a core network (not shown) via a wireless backhaul link. One or more memories 1622 may include instructions 1625, which, when executed by one or more processors 1621, may cause device 1620 to perform operations related to the aforementioned source base station 120A, target MWAB node 120B, or third base station 120C.

[0166] Figure 16CAn apparatus 1630 according to an example embodiment of the present disclosure is shown. The apparatus 1630 may be implemented to include or be used to form at least a portion of an optimized entity (such as the optimized entity 130 discussed above). Figure 16C As shown, device 1630 may include one or more processors 1631, one or more memories 1632, and one or more network interfaces 1637 interconnected via one or more buses 1634. The one or more buses 1634 may be address, data, or control buses and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optic cable, optics, or other optical communication device. The one or more network interfaces 1637 may provide wired or wireless communication links through which device 1630 can communicate with a UE, network nodes, and / or network functions. The one or more memories 1632 may include instructions 1635, which, when executed by the one or more processors 1631, may cause device 1630 to perform operations related to the optimized entity 130 discussed above.

[0167] The one or more processors 1611, 1621, and 1631 discussed above can be any suitable type for a local technology network and can include one or more of the following: general-purpose processors, special-purpose processors, microprocessors, digital signal processors (DSPs), one or more processors in a processor-based multi-core processor architecture, and special-purpose processors such as those developed based on field-programmable gate arrays (FPGAs) and application-specific integrated circuits (ASICs). The one or more processors 1611, 1621, and 1631 can be configured as other elements of control devices 1610, 1620, and 1630, and operate cooperatively with them to perform the operations discussed above.

[0168] One or more memories 1612, 1622, and 1632 may include at least one storage medium of various forms, such as transient and / or non-transient memory. Transient memory may include, but is not limited to, for example, random access memory (RAM) or cache. Non-transient memory may include, but is not limited to, for example, read-only memory (ROM), hard disk, flash memory, etc. As used herein, the term "non-transient" refers to a limitation on the medium itself (i.e., tangible, not tactile), rather than a limitation on the persistence of data storage (e.g., RAM versus ROM). Furthermore, one or more memories 1612, 1622, and 1632 may include, but are not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or equipment, or any combination thereof.

[0169] It should be understood that the blocks in the figures can be implemented in various ways, including software, hardware, firmware, or any combination thereof. In some embodiments, one or more blocks may be implemented using software and / or firmware (e.g., machine-executable instructions stored in a storage medium). As a supplement to or alternative to the machine-executable instructions, some or all of the blocks in the figures may be implemented at least partially by one or more hardware logic components. For example, but not limited to, illustrative types of hardware logic components that may be used include field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), system-on-a-chip (SoCs), complex programmable logic devices (CPLDs), etc.

[0170] Some example embodiments also provide program instructions that, when executed by one or more processors, cause a device or apparatus to perform the operations described above. The program instructions may be written in any combination of one or more programming languages. The program instructions may be provided to one or more processors or controllers of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that, when executed by the processor or controller, the program instructions cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program instructions may be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0171] Some example embodiments also provide a computer program product or computer-readable medium in which program instructions are stored. A computer-readable medium can be any tangible medium that may contain or store a program used by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. More specific examples of machine-readable storage media will include electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable optical disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0172] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements is connected by “and” or “or”, means at least any one of the elements, or at least any two or more of the elements, or at least all of the elements.

[0173] Furthermore, although operations are described in a specific order, this should not be construed as requiring that such operations be performed in the specific order shown or sequentially, or requiring that all shown operations be performed to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, while several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of this disclosure, but rather as a description of features that may be specific to particular embodiments. Certain features described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0174] Throughout this disclosure, references to "one embodiment," "embodiment," "some embodiments," "other embodiments," etc., indicate that one or more specific features, structures, steps, concepts, and / or characteristics based on the principles of this disclosure may be included in an embodiment. However, such references do not necessarily imply that all embodiments include a specific feature, structure, step, concept, and / or characteristic, or that an embodiment includes all features, structures, steps, concepts, and / or characteristics. Some embodiments may include one or more such features, structures, steps, concepts, and / or characteristics, and various combinations thereof. It should be understood that one or more of the features, structures, steps, concepts, and / or characteristics described with reference to one embodiment may be combined with one or more of the features, structures, steps, concepts, and / or characteristics of any other embodiment provided herein. That is, any features, structures, steps, concepts, and / or characteristics described herein may be mixed and matched to create hybrid embodiments, and such hybrid embodiments are within the scope of this disclosure. Furthermore, references to "one embodiment," "embodiment," "some embodiments," "other embodiments," etc., in various places in the specification do not necessarily refer to the same embodiment, nor are they necessarily exclusive single or alternative embodiments to other embodiments. It should also be understood that the various features, structures, steps, concepts, and / or characteristics of the disclosed embodiments are independent and separate from each other, and may be used or present individually or in various combinations thereof to create alternative embodiments that are considered part of this disclosure. Therefore, this disclosure is not limited to the embodiments specifically described herein, as describing all the many possible combinations and sub-combinations of features, structures, steps, concepts, and / or characteristics would be redundant, and the examples of embodiments disclosed herein are not intended to limit the broader aspects of this disclosure.

[0175] Although the subject matter has been described in language specific to structural features and / or methodological actions, it should be understood that the subject matter defined in the appended claims is not limited to the specific features or actions described above. Rather, the specific features and actions described above are disclosed as examples of implementing the claims.

[0176] Furthermore, the various implementations of this disclosure can be described with reference to the following terms, and their features can be combined in any reasonable manner.

[0177] Clause 1. An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to perform at least: detecting a failure or near failure associated with a handover process for the apparatus, wherein a target network node for the handover process is a mobile radio access backhaul node; and sending a report to the network node, the report including the time of occurrence of the failure or near failure.

[0178] Clause 2. The apparatus according to Clause 1, wherein the report further includes the cause of the failure or near failure.

[0179] Clause 3. The apparatus according to Clause 2, wherein the cause of the failure or near failure includes at least one of the following: measurement report conditions are not met; measurement reports are lost due to poor channel conditions; a handover command is not received; or a timer exceeds a threshold.

[0180] Clause 4. The apparatus according to Clause 1, wherein the failure or near failure associated with the handover process includes at least one of the following: a radio link failure at the source cell before the handover process is performed, a radio link failure during the execution of the handover process, a radio link failure at the target cell for a predetermined period of time after a successful handover from the source cell to the target cell, or a near failure during the handover process.

[0181] Clause 5. The apparatus according to Clause 1, wherein the report includes at least one of the following: radio link failure report, successful handover report, successful primary / secondary cell change report, self-organizing network report, or minimized drive test report.

[0182] Clause 6. The apparatus according to Clause 1, wherein the network node is: a source network node or the target network node for the apparatus during the handover process, to which the apparatus connects via a reconstruction process after the failure associated with the handover process; or a third network node other than the source network node and the target network node, to which the apparatus connects via a reconstruction process after the failure associated with the handover process; or the target network node to which the apparatus connects via the handover process, the apparatus experiencing a near failure during the handover process.

[0183] Clause 7. The apparatus according to Clause 1, wherein the instructions, when executed by the at least one processor, further cause the apparatus to perform at least: receiving an indication indicating that the target network node is a mobile radio access backhaul node in a handover command during the handover process, or receiving an indication indicating that the target network node is a mobile radio access backhaul node from a source network node, wherein the apparatus, in response to the indication, includes in the report the time of occurrence of the failure or the near failure.

[0184] Clause 8. An apparatus comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to perform at least: receiving a report indicating a failed user equipment (UE) associated with a handover process; during the handover process, sending a request for mobility information of a target network node for the UE, the target network node being a mobile radio access backhaul node, the request indicating a first time; receiving from the target network node mobility information of the target network node at the first time and mobility information of the target network node at a second time; enhancing the report of the UE based on the received mobility information of the target network node at the first time and the second time; and sending the enhanced report to an optimization entity.

[0185] Clause 9. The apparatus according to Clause 8, wherein the report of the user equipment is received from the user equipment when the user equipment re-establishes its connection with the apparatus via a reconstruction process after the failure associated with the handover process, or the report of the user equipment is received from the third network node when the user equipment re-establishes its connection with a third network node other than the source network node and the target network node via a reconstruction process after the failure associated with the handover process.

[0186] Clause 10. The apparatus according to Clause 9, wherein the first moment is included in the report of the user equipment, indicating the time when the failure associated with the handover process occurs, or indicating the time when the user equipment re-establishes the connection with the third network node in the event that the user equipment has connected to the third network node after the failure associated with the handover process, or the first moment is determined at the apparatus, indicating the time when the user equipment re-establishes the connection with the apparatus in the event that the user equipment has connected to the apparatus after the failure associated with the handover process.

[0187] Clause 11. The apparatus according to Clause 8, wherein the mobility information includes at least one of the following: the location of the target network node, the speed of the target network node, the distance traveled by the target network node, or the current time at the target network node.

[0188] Clause 12. The apparatus according to Clause 8, wherein the second moment refers to the time during which the target network node allows the user equipment to switch to the target network node during the handover process.

[0189] Clause 13. The apparatus according to Clause 8, wherein the report of the user equipment further indicates the cause of the failure associated with the handover process, including at least one of the following: measurement report conditions are not met; measurement reports are lost due to poor channel conditions; or a handover command is not received.

[0190] Clause 14. An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: establish a connection with a user equipment via the handover or reconstruction process after a handover process; receive from the user equipment a report of failure or near failure associated with the handover process; enhance the report based on mobility information of the apparatus at a first time and a second time, the first time being the time when the failure or near failure associated with the handover process occurs, the time when the handover process is successfully executed, or the time when the reconstruction process is executed, the second time being the time when the apparatus allows the user equipment to hand over from a source network node to the apparatus during the handover process; and send the enhanced report to an optimization entity.

[0191] Clause 15. The device according to Clause 14, wherein the mobility information includes at least one of the following: the location of the device, the speed of the device, the distance traveled by the device, or the current time at the device.

[0192] Clause 16. The apparatus according to Clause 14, wherein the failure or near failure associated with the handover process includes at least one of the following: a radio link failure at the source cell prior to the handover process being performed, or a near failure during the handover process.

[0193] Clause 17. An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to perform at least: re-establish a connection with a user equipment via a reconstruction process; receive from the user equipment a report of a failure associated with a handover process, the report indicating a second moment in which the failure occurred; enhance the report using mobility information of the apparatus at a first moment and the second moment, the first moment referring to the time when the connection with the user equipment was re-established; and send the enhanced report to an optimization entity.

[0194] Clause 18. The apparatus according to Clause 17, wherein the report received from the user equipment further indicates the cause of the failure associated with the handover process, including at least one of the following: measurement report conditions are not met; measurement reports are lost due to poor channel conditions; or a handover command is not received.

[0195] Clause 19. An apparatus comprising: at least one processor; and at least one memory storing instructions, the instructions, when executed by the at least one processor, causing the apparatus to at least: receive a request from a network node for mobility information at a first time; and send a response to the network node containing mobility information of the apparatus at the first time and a second time, the second time being the time during which the apparatus allows the user equipment to switch from a source network node to the apparatus during the handover process.

[0196] Clause 20. The apparatus according to Clause 19, wherein the first moment indicates the time at which a failure associated with the handover process occurs, or the time at which a reconstruction process is performed for the user equipment after the failure associated with the handover process.

[0197] Clause 21. The apparatus according to Clause 19, wherein the network node is: the source network node for the user equipment during the handover process, or a third network node other than the source network node and the target network node, to which the user equipment connects via a reconstruction process or an optimization entity after the failure associated with the handover process.

[0198] Clause 22. An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: receive a report of a failure or near failure associated with a handover process for a user equipment to a target network node implemented as a mobile radio access backhaul node, the report including mobility information of the target network node; and, based on the mobility information of the target network node, determine whether the failure or near failure is caused by the mobility of the target network node.

[0199] Clause 23. The apparatus according to Clause 22, wherein the instructions, when executed by the at least one processor, further cause the apparatus to at least: ignore the report if the failure and the near failure are caused by the mobility of the target network node; or update the performance indicator for the handover process based on the report if the failure and the near failure are not caused by the mobility of the target network node.

[0200] Clause 24. The apparatus according to Clause 23, wherein the performance indicator includes at least one of the following: premature handover to a mobile radio access backhaul indicator, late handover to a mobile radio access backhaul indicator, erroneous cell change to a mobile radio access backhaul indicator, near-failure handover to a mobile radio access backhaul indicator, or near-failure primary / secondary cell change to a mobile radio access backhaul indicator.

[0201] Clause 25. The apparatus according to Clause 22, wherein the mobility information of the target network node includes one or more of the following: mobility information of the target network node during handover preparation, mobility information of the target network node during handover execution, mobility information of the target network node during a time period after the handover process, or mobility information of the target network node during a reconstruction process after the handover process.

[0202] Clause 26. The apparatus according to Clause 22, wherein the optimization entity includes a radio access network node, or a core network node, or a radio access network intelligent controller, or an operation, management and maintenance entity.

[0203] Clause 27. The apparatus according to Clause 22, wherein the report further indicates the cause of the failure or near failure associated with the handover process, and whether the failure or near failure is caused by the mobility of the target network node is further determined based on the cause of the failure or near failure.

[0204] Clause 28. An apparatus comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause an optimization entity to at least: receive a report of a failure or near failure associated with a handover process for a user equipment to a target network node implemented as a mobile radio access backhaul node, the report indicating a first moment at which the failure or near failure associated with the handover process occurs, or a first moment at which a reconstruction process is executed after the failure associated with the handover process; send a request to the target network node for mobility information of the target network node, the request indicating the first moment; receive from the target network node mobility information of the target network node at the first moment and mobility information of the target network node at a second moment, the second moment being the time during which the target network node allows the user equipment to handover during the handover process; and determine, based on the mobility information of the target network node at the first moment and the second moment, whether the failure or near failure is caused by the mobility of the target network node.

[0205] Clause 29. The apparatus according to Clause 28, wherein the instructions, when executed by the at least one processor, further cause the apparatus to at least: ignore the report if the failure or near failure is caused by the mobility of the target network node; or update a key performance indicator for the handover process based on the report if the failure or near failure is not caused by the mobility of the target network node.

[0206] Clause 30. The apparatus according to Clause 28, wherein the instructions, when executed by the at least one processor, further cause the apparatus to at least: enhance the report based on the mobility information of the target network node at the first time and the second time.

[0207] Clause 31. The apparatus according to Clause 28, wherein the report further indicates the cause of the failure or near failure associated with the handover process, and whether the failure or near failure is caused by the mobility of the target network node is further determined based on the cause of the failure or near failure.

[0208] Clause 32. A method comprising: detecting at a user equipment a failure or near failure associated with a handover process, wherein the target network node for the handover process is a mobile radio access backhaul node; and sending a report to the network node, the report including the time of occurrence of the failure or near failure.

[0209] Clause 33. The method described in Clause 32, wherein the report further includes the cause of the failure or near failure.

[0210] Clause 34. The method according to Clause 33, wherein the cause of the failure or near failure includes at least one of the following: measurement report conditions are not met; measurement reports are lost due to poor channel conditions; a handover command is not received; or a timer exceeds a threshold.

[0211] Clause 35. The method according to Clause 32, wherein the failure or near failure associated with the handover process includes at least one of the following: a radio link failure at the source cell before the handover process is performed, a radio link failure during the execution of the handover process, a radio link failure at the target cell within a predetermined time period after a successful handover from the source cell to the target cell, or a near failure during the handover process.

[0212] Clause 36. The method according to Clause 32, wherein the report includes at least one of the following: radio link failure report, successful handover report, successful primary / secondary cell change report, self-organizing network report, or minimized drive test report.

[0213] Clause 37. The method according to Clause 32, wherein the network node is: a source network node or the target network node for the user equipment during the handover process, to which the user equipment connects via a reconstruction process after the failure associated with the handover process; or a third network node other than the source network node and the target network node, to which the user equipment connects via a reconstruction process after the failure associated with the handover process; or the target network node to which the user equipment connects via the handover process, the user equipment experiencing a near failure during the handover process.

[0214] Clause 38. The method according to Clause 32 further comprises: receiving an indication indicating that the target network node is a mobile radio access backhaul node in a handover command during the handover process, or receiving an indication indicating that the target network node is a mobile radio access backhaul node from a source network node, wherein the user equipment includes the time of occurrence of the failure or near failure in the report in response to the indication.

[0215] Clause 39. A method comprising: receiving at a network node a report indicating a failed user equipment (UE) associated with a handover process; during the handover process, sending a request for mobility information of a target network node for the UE, the target network node being a mobile radio access backhaul node, the request indicating a first time; receiving from the target network node mobility information of the target network node at the first time and mobility information of the target network node at a second time; enhancing the report of the UE based on the received mobility information of the target network node at the first time and the second time; and sending the enhanced report to an optimization entity.

[0216] Clause 40. The method according to Clause 39, wherein the report of the user equipment is received from the user equipment when the user equipment re-establishes its connection with the network node through a reconstruction process after the failure associated with the handover process, or the report of the user equipment is received from the third network node when the user equipment re-establishes its connection with a third network node other than the source network node and the target network node through a reconstruction process after the failure associated with the handover process.

[0217] Clause 41. The method according to Clause 40, wherein the first moment is included in the report of the user equipment, indicating the time when the failure associated with the handover process occurs, or indicating the time when the user equipment re-establishes the connection with the third network node in the event that the user equipment has connected to the third network node after the failure associated with the handover process, or the first moment is determined at the network node, indicating the time when the user equipment re-establishes the connection with the network node in the event that the user equipment has connected to the network node after the failure associated with the handover process.

[0218] Clause 42. The method according to Clause 39, wherein the mobility information includes at least one of the following: the location of the target network node, the speed of the target network node, the distance traveled by the target network node, or the current time at the target network node.

[0219] Clause 43. The method according to Clause 39, wherein the second moment refers to the time during which the target network node allows the user equipment to switch to the target network node during the handover process.

[0220] Clause 44. The method according to Clause 39, wherein the report of the user equipment further indicates the cause of the failure associated with the handover process, including at least one of the following: measurement report conditions are not met; measurement reports are lost due to poor channel conditions; or a handover command is not received.

[0221] Clause 45. A method comprising: establishing a connection with a user equipment at a target network node via the handover or reconstruction process after a handover process, the target network node being implemented as a mobile radio access backhaul node; receiving from the user equipment a failure or near failure report associated with the handover process; enhancing the report based on mobility information of the target network node at a first time and a second time, the first time being the time when the failure or near failure associated with the handover process occurs, the time when the handover process is successfully executed, or the time when the reconstruction process is executed, the second time being the time when the target network node allows the user equipment to hand over from a source network node to the target network node during the handover process; and sending the enhanced report to an optimization entity.

[0222] Clause 46. The method according to Clause 45, wherein the mobility information includes at least one of the following: the location of the target network node, the speed of the target network node, the distance traveled by the target network node, or the current time at the target network node.

[0223] Clause 47. The method according to Clause 45, wherein the failure or near failure associated with the handover process includes at least one of the following: a radio link failure at the source cell prior to the handover process being performed, or a near failure during the handover process.

[0224] Clause 48. A method comprising: re-establishing a connection with a user equipment at a target network node via a reconstruction process, the target network node being implemented as a mobile radio access backhaul node; receiving from the user equipment a failure report associated with a handover process, the report indicating a second moment in which the failure occurred; enhancing the report using mobility information of the target network node at a first moment and the second moment, the first moment referring to the time when the connection with the user equipment was re-established; and sending the enhanced report to an optimization entity.

[0225] Clause 49. The method according to Clause 48, wherein the report received from the user equipment further indicates the cause of the failure associated with the handover process, including at least one of the following: measurement report conditions are not met; measurement reports are lost due to poor channel conditions; or a handover command is not received.

[0226] Clause 50. A method comprising: receiving, at a mobile radio access backhaul node, a request from a network node for mobility information at a first time, the mobile radio access backhaul node serving as a target network node for a user equipment during a handover process; and sending to the network node a response comprising mobility information of the mobile radio access backhaul node at the first time and a second time, the second time being a time during which the mobile radio access backhaul node permits the user equipment to handover from a source network node to the mobile radio access backhaul node during the handover process.

[0227] Clause 51. The method according to Clause 50, wherein the first moment indicates the time when a failure associated with the handover process occurs, or the time when a reconstruction process is performed for the user equipment after the failure associated with the handover process.

[0228] Clause 52. The method according to Clause 50, wherein the network node is: the source network node for the user equipment during the handover process, or a third network node other than the source network node and the target network node, to which the user equipment connects via a reconstruction process or an optimization entity after the failure associated with the handover process.

[0229] Clause 53. A method comprising: receiving at an optimization entity a report of failure or near failure associated with a handover process for a user equipment to a target network node implemented as a mobile radio access backhaul node, the report including mobility information of the target network node; and determining, based on the mobility information of the target network node, whether the failure or near failure is caused by the mobility of the target network node.

[0230] Clause 54. The method according to Clause 53 further comprises: ignoring the report if the failure and the near failure are caused by the mobility of the target network node; or updating the performance indicator for the handover process based on the report if the failure and the near failure are not caused by the mobility of the target network node.

[0231] Clause 55. The method according to Clause 54, wherein the performance indicator includes at least one of the following: premature handover to a mobile radio access backhaul indicator, late handover to a mobile radio access backhaul indicator, erroneous cell change to a mobile radio access backhaul indicator, near-failure handover to a mobile radio access backhaul indicator, or near-failure primary / secondary cell change to a mobile radio access backhaul indicator.

[0232] Clause 56. The method according to Clause 53, wherein the mobility information of the target network node includes one or more of the following: mobility information of the target network node during handover preparation, mobility information of the target network node during handover execution, mobility information of the target network node during a time period after the handover process, or mobility information of the target network node during the reconstruction process after the handover process.

[0233] Clause 57. The method described in Clause 53, wherein the optimization entity includes a radio access network node, or a core network node, or a radio access network intelligent controller, or an operation, management and maintenance entity.

[0234] Clause 58. The method according to Clause 53, wherein the report further indicates the cause of the failure or near failure associated with the handover process, and whether the failure or near failure is caused by the mobility of the target network node is further determined based on the cause of the failure or near failure.

[0235] Clause 59. A method comprising: at an optimization entity, receiving a report of a failure or near failure associated with a handover process for a user equipment to a target network node implemented as a mobile radio access backhaul node, the report indicating a first moment at which the failure or near failure associated with the handover process occurs, or a first moment at which a reconstruction process is performed after the failure associated with the handover process; sending a request to the target network node for mobility information of the target network node, the request indicating the first moment; receiving from the target network node mobility information of the target network node at the first moment and mobility information of the target network node at a second moment, the second moment being the time during which the target network node allows the user equipment to handover during the handover process; and determining, based on the mobility information of the target network node at the first moment and the second moment, whether the failure or near failure is caused by the mobility of the target network node.

[0236] Clause 60. The method according to Clause 59 further comprises: ignoring the report if the failure or near failure is caused by the mobility of the target network node; or updating key performance indicators for the handover process based on the report if the failure or near failure is not caused by the mobility of the target network node.

[0237] Clause 61. The method according to Clause 59 further includes: enhancing the report based on the mobility information of the target network node at the first time and the second time.

[0238] Clause 62. The method according to Clause 59, wherein the report further indicates the cause of the failure or near failure associated with the handover process, and whether the failure or near failure is caused by the mobility of the target network node is further determined based on the cause of the failure or near failure.

[0239] Clause 63. An apparatus comprising components for performing the method according to any one of Clauses 32 to 62.

[0240] Clause 64. A computer-readable medium comprising instructions that, when executed by a device, cause the device to perform the method according to any one of Clauses 32 to 62.

Claims

1. A device for communication, comprising: At least one processor; as well as At least one memory stores instructions that, when executed by the at least one processor, cause the device to perform at least the following: Detecting failures or near-failures associated with a handover process for the device, wherein the target network node for the handover process is a mobile radio access backhaul node; and A report is sent to the network node, the report including the time when the failure or near failure occurred.

2. The apparatus of claim 1, wherein the report further includes the cause of the failure or near failure.

3. The apparatus of claim 2, wherein the cause of the failure or near failure includes at least one of the following: The conditions for the measurement report were not met; Measurement reports were lost due to poor channel conditions; No switch command received; or The timer has exceeded the threshold.

4. The apparatus of claim 1, wherein the failure or near failure associated with the switching process comprises at least one of the following: The radio link at the source cell failed before the handover process was performed. The radio link failed during the execution of the handover process. The radio link at the target cell fails within a predetermined time period following a successful handover from the source cell to the target cell, or Near failure during the switching process.

5. The apparatus of claim 1, wherein the report comprises at least one of the following: Radio link failure report Report successfully switched. Successful main and auxiliary community change report Self-organizing network reporting, or Minimize road test reports.

6. The apparatus of claim 1, wherein the network node is: During the handover process, if the source network node or target network node of the device fails in connection with the handover process, the device reconnects to the source network node or target network node via a reconstruction process, or In addition to the source network node and the target network node, following the failure associated with the handover process, the device connects to the third network node via a reconstruction process, or The target network node, the device connects to the target network node through the handover process, and the device experiences near failure during the handover process.

7. The apparatus of claim 1, wherein the instructions, when executed by the at least one processor, further cause the apparatus to perform at least: Receive an indication that the target network node is a mobile radio access backhaul node in the handover command during the handover process, or Receive an indication that the target network node is a mobile radio access backhaul node from the source network node. The device, in response to the instruction, includes in the report the time of occurrence of the failure or near failure.

8. A device for communication, comprising: At least one processor; as well as At least one memory stores instructions that, when executed by the at least one processor, cause the device to perform at least the following: Receive reports of failed user equipment associated with the handover process; During the handover process, a request for mobility information of the target network node, which is a mobile radio access backhaul node, is sent to the target network node for the user equipment. The request indicates a first moment. Receive the mobility information of the target network node at the first time and the mobility information of the target network node at the second time from the target network node; The user equipment's report is enhanced based on the mobility information received from the target network node at the first and second time points; as well as Send the enhanced report to the optimized entity.

9. A device for communication, comprising: At least one processor; as well as At least one memory stores instructions that, when executed by the at least one processor, cause the device to perform at least the following: After the handover process, a connection is established with the user equipment through the handover or reconstruction process; Receive a report of failure or near failure associated with the handover process from the user equipment; The report is enhanced based on the mobility information of the device at a first time and a second time, wherein the first time refers to the time when the failure or near failure associated with the handover process occurs, the time when the handover process is successfully executed, or the time when the reconstruction process is executed, and the second time refers to the time during which the device allows the user equipment to hand over from the source network node to the device during the handover process. as well as Send the enhanced report to the optimized entity.

10. A method for communication, comprising: Detecting failures or near-failures associated with the handover process at the user equipment, wherein the target network node for the handover process is a mobile radio access backhaul node; as well as A report is sent to the network node, the report including the time when the failure or near failure occurred.

Images