Systems and methods for enhancements related to non-terrestrial network
By enhancing SON and MDT functionalities with NTN-specific information, the system addresses mobility challenges in satellite-based communication, improving network performance and reliability in non-terrestrial networks.
Patent Information
- Application Number
- PCT/CN2024/083576
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-03-25
- Publication Date
- 2025-07-31
AI Technical Summary
Existing wireless communication systems, particularly in non-terrestrial networks (NTN), face challenges in optimizing network performance due to the unique mobility and coverage characteristics of satellite-based communication, which are not adequately addressed by current self-organizing network (SON) and minimization of drive test (MDT) functionalities.
The system and methods enhance SON and MDT functionalities by enabling wireless communication devices to provide specific information related to non-terrestrial networks, including cell type, measurement parameters, and satellite switch procedures, to improve network optimization and performance in NTN environments.
Enhanced SON and MDT functionalities lead to improved network performance and reliability in NTN scenarios by addressing mobility issues related to time-based and location-based conditional handovers and optimizing network configurations for satellite-based communication.
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Figure CN2024083576_31072025_PF_FP_ABST
Abstract
Description
SYSTEMS AND METHODS FOR ENHANCEMENTS RELATED TO NON-TERRESTRIAL NETWORKTECHNICAL FIELD
[0001] The disclosure relates generally to wireless communications, including but not limited to systems and methods for self-organizing networks (SON) and / or minimization of drive test (MDT) enhancements for non-terrestrial network (NTN) .BACKGROUND
[0002] The standardization organization Third Generation Partnership Project (3GPP) is currently in the process of specifying a new Radio Interface called 5G New Radio (5G NR) as well as a Next Generation Packet Core Network (NG-CN or NGC) . The 5G NR will have three main components: a 5G Access Network (5G-AN) , a 5G Core Network (5GC) , and a User Equipment (UE) . In order to facilitate the enablement of different data services and requirements, the elements of the 5GC, also called Network Functions, have been simplified with some of them being software based, and some being hardware based, so that they could be adapted according to need. Communication via satellite is one of the typical scenarios of the non-terrestrial networks in 3GPP standardization.SUMMARY
[0003] The example embodiments disclosed herein are directed to solving the issues relating to one or more of the problems presented in the prior art, as well as providing additional features that will become readily apparent by reference to the following detailed description when taken in conjunction with the accompany drawings. In accordance with various embodiments, example systems, methods, devices and computer program products are disclosed herein. It is understood, however, that these embodiments are presented by way of example and are not limiting, and it will be apparent to those of ordinary skill in the art who read the present disclosure that various modifications to the disclosed embodiments can be made while remaining within the scope of this disclosure.
[0004] At least one aspect is directed to a system, method, apparatus, or a computer-readable medium of the following. A wireless communication device (e.g., a user equipment (UE) ) may send an uplink (UL) message (e.g., UEinformationresponse message) to a wireless communication node (e.g., a gNB or a base station (BS) ) . The UL message may comprise information related to a non-terrestrial network (NTN) . In some embodiments, the wireless communication device (e.g., a user equipment (UE) ) may receive configuration information (e.g., LoggedMeasurementConfiguration) for optimizing network performance from the wireless communication node (e.g., a gNB or a base station (BS) ) .
[0005] In some embodiments, the information may include an indication that a cell related to at least one of the wireless communication device or the wireless communication node, is part of the NTN. In some embodiments, the information may comprise at least one of: frequency information of the cell, or an indication of whether the cell is part of the NTN. In some embodiments, the cell may comprise at least one of: a serving cell that performs a logged measurement in a logged measurement report; at least one neighbor cell that performs the logged measurement in the logged measurement report; a cell at which the last measurement results was taken, where connection establishment failure or connection resume failure happened in a connection failure report; at least one neighbor cell at which the last measurement results was taken, where connection establishment failure or connection resume failure happened in a connection failure report; a primary cell (PCell) in which radio link failure (RLF) is detected or a target PCell of a failed handover in a radio link failure report; at least one candidate target cell for conditional handover at a time of connection failure in a radio link failure report; a candidate target cell for conditional handover that the wireless communication device selected for conditional handover (CHO) in a radio link failure report; a PCell in which radio link failure (RLF) is detected or a source PCell of a failed handover in an evolved universal terrestrial radio access (E-UTRA) radio link failure report; at least one neighbor E-UTRA cell that the last measurement results were taken, when radio link failure or handover failure happened in a radio link failure report; at least one neighbor new radio (NR) cell that the last measurement results were taken, when radio link failure or handover failure happened in a radio link failure report; a source PCell of a last handover in a radio link failure report; a PCell in which the wireless communication device failed to perform fast master cell group (MCG) recovery procedure or the wireless communication device successfully performed fast MCG recovery procedure in a radio link failure report; a cell in which the wireless communication device comes back to connected after connection failure and after failing to perform reestablishment in a radio link failure report; a cell in which a re-establishment attempt was made after connection failure in a radio link failure report; a target PCell of a handover for which a successful handover report was generated in a successful handover report; a target E-UTRA PCell of a handover in which the successful handover triggers a successful handover report; at least one neighboring NR cell that the last measurement results were taken when a successful handover is executed in a successful handover report; a source PCell of a handover in which the successful handover triggers a successful handover report; a target PCell of a handover in which the successful handover triggers a successful handover report; at least one neighbor cell that the last measurement was taken when a successful primary cell of a secondary cell group (SCG) (PSCell) change or addition is executed; a PCell to which the wireless communication device was connected when a successful PSCell change or addition in a successful PSCell report; a source PSCell of a PSCell change in which a successful PSCell change in a successful PSCell report; a target PSCell of a PSCell change in which the successful PSCell change in a successful PSCell report; or recently visited cell (s) in mobility history information.
[0006] In some embodiments, the information may include at least one NTN related measurement parameter. The at least one NTN related measurement parameter may comprise at least one of: an indication of a type of a NTN related measurement that is performed in RRC_IDLE state and / or RRC_INACTIVE state, wherein the NTN related measurement is a location-based measurement or a time-based measurement; an indication of a distance threshold that is used in location-based measurement initiation in RRC_IDLE state and / or RRC_INACTIVE state; an indication of a reference location of a serving cell at a time reference that is used in location-based measurement initiation in RRC_IDLE state and / or RRC_INACTIVE state; or a list of terrestrial network (TN) coverage area information that is used to assist skipping TN measurements for NTN user equipment (UEs) in RRC_IDLE and / or RRC_INACTIVE state.
[0007] In some embodiments, the information may include at least one NTN related parameter. The at least one NTN related parameter may comprise at least one of: time information regarding when a cell provided by an NTN system ceases serving the area the cell is currently covering; an indication of whether a last executed handover was an intra-NTN handover; an indication of whether a connection failure is due to a failure in an intra-NTN handover or an intra-NTN radio link; or a list of NTN neighbor cells.
[0008] In some embodiments, the information may include time-based conditional handover (CHO) information or location-based CHO information. In some embodiments, the time-based information may comprise at least one of: an indication of an absolute time when a radio link failure (RLF) or handover failure is caused by time-based CHO; an indication of the absolute time when a successful handover is detected by time-based CHO; an indication of a time threshold that is used for time-based CHO; an indication of a duration that is used for defining a leaving condition for time-based CHO; an indication of a last executed handover before a last detected connection failure is a time-based CHO; an indication of a last executed handover before a last detected connection failure is a time-based CHO that is performed via random access channel (RACH) -less; an indication of whether a connected failure is due to a time-based CHO; or an indication of whether a connected failure is due to a time-based CHO that is performed via RACH-less. In some embodiments, the location-based CHO information may comprise at least one of: an indication of a location of the wireless communication device when a radio link failure (RLF) or handover failure is caused by location-based CHO; an indication of coarse location of the wireless communication device when a radio link failure (RLF) or handover failure is caused by location-based CHO; an indication of a location of the wireless communication device when a successful handover is detected by location-based CHO; an indication of coarse location of the wireless communication device when a successful handover is detected by location-based CHO; an indication of one or more reference locations that are used for location-based CHO; an indication of one or more distance thresholds that are used for location-based CHO; an indication of a distance between the wireless communication device and the one or more reference locations when the RLF, the handover failure, or the successful handover is detected by location-based CHO; an indication of a last executed handover before a last detected connection failure is a location-based CHO; or an indication of whether a connected failure is due to a location-based CHO.
[0009] In some embodiments, the configuration information may include a logged measurement configuration for at least one NTN cell. The logged measurement configuration may comprise at least one of: a list of tracking area codes for a tracking area identity in area configuration for logged measurement; an area configuration for an NTN system, wherein the area configuration includes a reference location and a distance threshold; or at least one coordinate point to mark area configuration for logged measurement. The present application provides an area configuration for an NTN system. There can be a reference location and a distance threshold. When the distance between the UE and the reference location is shorter than the distance threshold, the UE can perform the logged measurement. The present application provides one or more coordinate points to mark an area configuration for logged measurement. In certain embodiments, the present application provides an area configuration for NTN system. There can be a reference location and a distance threshold. When the distance between the UE and the reference location is shorter than the distance threshold, the UE may skip the logged measurement.
[0010] In some embodiments, the information may include random access channel (RACH) -less handover information. The RACH-less handover information may comprise at least one of: an indication of a last executed handover being a RACH-less handover; an indication of whether a connected failure is due to a RACH-less handover failure; or at least one RACH-less handover related parameter.
[0011] In some embodiments, the at least one RACH-less handover related parameter may comprise at least one of: an indication of reference signal received power (RSRP) for synchronization signal block (SSB) selection for a pre-allocated uplink grant; an initial value of a configured grant retransmission timer used for an initial uplink transmission of the RACH-less handover; a set of demodulation reference signal (DMRS) ports for SSB to physical uplink shared channel (PUSCH) mapping for the RACH-less handover; a number of DMRS sequences for SSB to PUSCH mapping for the RACH-less handover; a threshold of the RSRP configured for SSB selection for the pre-allocated uplink grant for the RACH-less handover; a number of SSBs per pre-allocated uplink grant PUSCH for the RACH-less handover; or a SSB subset for SSB to configured grant (CG) PUSCH mapping within a CG configuration for the RACH-less handover.
[0012] In some embodiments, the information may include information regarding a satellite switch procedure. In some embodiments, the information regarding the satellite switch procedure may comprise at least one of: an indicator if a random access procedure is initiated for the satellite switch with a re-synchronization procedure; a cause of radio link failure (RLF) to indicate whether the RLF is due to a consecutive satellite switch with a re-synchronization procedure; or at least one parameter regarding the satellite switch with a re-synchronization procedure. The at least one parameter regarding the satellite switch with a re-synchronization procedure may comprise at least one of: an indication of a time since a last satellite switch with a re-synchronization execution until a loss of UL synchronization due to the satellite switch with a re-synchronization procedure; an indication of an absolute time when the UL synchronization is lost due to the satellite switch with a re-synchronization procedure; an indication of a validity duration for NTN related assistance information; a number of latest consecutive satellite switch with a re-synchronization procedure failure; an indication of an absolute time when the satellite switch with a re-synchronization procedure is obtained; an indication of a time since a first loss of UL synchronization due to the satellite switch with the re-synchronization procedure until the UL synchronization is obtained; or an indication of a physical cell identifier (PCI) of a source satellite; an indication of a PCI of a target satellite; an indication of a type of satellite switch that is a soft satellite switch; an indication of a type of satellite switch that is a hard satellite switch; an indication of whether the satellite switch is performed via a re-synchronization procedure; an indicator of whether the satellite switch is performed via a re-synchronization procedure without random access procedure; an indication of a time offset between a synchronization signal block (SSB) from a source satellite and a target satellite at a uplink time synchronization reference point; an indication of time information on when a target satellite is going to start serving an area currently covered by a serving satellite; or an indication of time information on when a cell provided via an NTN system is going to stop serving an area the cell is currently covering.
[0013] In some embodiments, the information may include satellite information of a first cell. The satellite information may comprise at least one of: an indication of an absolute time when a satellite is going to start serving the first cell; ephemeris information of a satellite when a satellite is going to start serving the first cell; or an indication of an epoch time of a satellite for NTN assistance information of the first cell. In some embodiments, the first cell may comprise at least one of: a serving cell that performs a logged measurement in a logged measurement report; at least one neighbor cell that performs the logged measurement in the logged measurement report; a cell at which the last measurement results was taken, where connection establishment failure or connection resume failure happened in a connection failure report; at least one neighbor cell at which the last measurement results was taken, where connection establishment failure or connection resume failure happened in the connection failure report; a primary cell (PCell) in which radio link failure (RLF) is detected or a target PCell of a failed handover in a radio link failure report; a candidate target cells for conditional handover at a time of connection failure in the radio link failure report; a candidate target cell for conditional handover that the wireless communication device selected for conditional handover (CHO) in the radio link failure report; a PCell in which radio link failure (RLF) is detected or a source PCell of a failed handover in an evolved universal terrestrial radio access (E-UTRA) radio link failure report; at least one neighbor E-UTRA cell that the last measurement results were taken, when radio link failure or handover failure happened in the radio link failure report; at least one neighbor new radio (NR) cell that the last measurement results were taken, when radio link failure or handover failure happened in the radio link failure report; a source PCell of a last handover in the radio link failure report; a PCell in which the wireless communication device failed to perform fast master cell group (MCG) recovery procedure or the wireless communication device successfully performed fast MCG recovery procedure in the radio link failure report; a cell in which the wireless communication device comes back to connected after connection failure and after failing to perform reestablishment in the radio link failure report; a cell in which a re-establishment attempt was made after connection failure in the radio link failure report; a target PCell of a handover for which a successful handover report was generated in a successful handover report; a target E-UTRA PCell of a handover in which the successful handover triggers the successful handover report; at least one neighboring NR cell that the last measurement results were taken when a successful handover is executed in the successful handover report; a source PCell of a handover in which the successful handover triggers the successful handover report; a target PCell of a handover in which the successful handover triggers the successful handover report; at least one neighbor cell that the last measurement was taken when a successful primary cell of a secondary cell group (SCG) (PSCell) change or addition is executed; a PCell to which the wireless communication device was connected when the successful PSCell change or addition in a successful PSCell report; a source PSCell of a PSCell change in which the successful PSCell change in the successful PSCell report; a target PSCell of a PSCell change in which the successful PSCell change in the successful PSCell report; or a recently visited cells in mobility history information.
[0014] In some embodiments, the information can be included in at least one of: a radio link failure report when a radio link failure is detected; a successful handover report when a successful handover is detected; a report that is stored when a satellite switch procedure is performed; a report of a logged measurement result; a report of a connection failure; or a report of mobility history information. In some embodiments, the information may include a duration of stay in an NTN cell.
[0015] In some embodiments, the wireless communication device may receive a request for the UL message from the wireless communication node. The wireless communication device may send the UL message according to the request to the wireless communication node.
[0016] In some embodiments, a wireless communication node (e.g., a gNB or a base station (BS) ) may receive an uplink (UL) message from a wireless communication device (e.g., a user equipment (UE) ) . The UL message may comprise information related to a non-terrestrial network (NTN) . In some embodiments, the wireless communication node (e.g., a gNB or a base station (BS) ) may send configuration information for optimizing network performance to the wireless communication device (e.g., a user equipment (UE) ) .BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Various example embodiments of the present solution are described in detail below with reference to the following figures or drawings. The drawings are provided for purposes of illustration only and merely depict example embodiments of the present solution to facilitate the reader's understanding of the present solution. Therefore, the drawings should not be considered limiting of the breadth, scope, or applicability of the present solution. It should be noted that for clarity and ease of illustration, these drawings are not necessarily drawn to scale.
[0018] FIG. 1 illustrates an example cellular communication network in which techniques disclosed herein may be implemented, in accordance with an embodiment of the present disclosure;
[0019] FIG. 2 illustrates a block diagram of an example base station and a user equipment device, in accordance with some embodiments of the present disclosure; and
[0020] FIG. 3 illustrates a flow diagram of an example method for enhancements related to a non-terrestrial network (NTN) , in accordance with an embodiment of the present disclosure.DETAILED DESCRIPTION
[0021] Mobile Communication Technology and Environment
[0022] FIG. 1 illustrates an example wireless communication network, and / or system, 100 in which techniques disclosed herein may be implemented, in accordance with an embodiment of the present disclosure. In the following discussion, the wireless communication network 100 may be any wireless network, such as a cellular network or a narrowband Internet of things (NB-IoT) network, and is herein referred to as “network 100. ” Such an example network 100 includes a base station 102 (hereinafter “BS 102” ; also referred to as wireless communication node) and a user equipment device 104 (hereinafter “UE 104” ; also referred to as wireless communication device) that can communicate with each other via a communication link 110 (e.g., a wireless communication channel) , and a cluster of cells 126, 130, 132, 134, 136, 138 and 140 overlaying a geographical area 101. In FIG. 1, the BS 102 and UE 104 are contained within a respective geographic boundary of cell 126. Each of the other cells 130, 132, 134, 136, 138 and 140 may include at least one base station operating at its allocated bandwidth to provide adequate radio coverage to its intended users.
[0023] For example, the BS 102 may operate at an allocated channel transmission bandwidth to provide adequate coverage to the UE 104. The BS 102 and the UE 104 may communicate via a downlink radio frame 118, and an uplink radio frame 124 respectively. Each radio frame 118 / 124 may be further divided into sub-frames 120 / 127 which may include data symbols 122 / 128. In the present disclosure, the BS 102 and UE 104 are described herein as non-limiting examples of “communication nodes, ” generally, which can practice the methods disclosed herein. Such communication nodes may be capable of wireless and / or wired communications, in accordance with various embodiments of the present solution.
[0024] FIG. 2 illustrates a block diagram of an example wireless communication system 200 for transmitting and receiving wireless communication signals (e.g., OFDM / OFDMA signals) in accordance with some embodiments of the present solution. The system 200 may include components and elements configured to support known or conventional operating features that need not be described in detail herein. In one illustrative embodiment, system 200 can be used to communicate (e.g., transmit and receive) data symbols in a wireless communication environment such as the wireless communication environment 100 of FIG. 1, as described above.
[0025] System 200 generally includes a base station 202 (hereinafter “BS 202” ) and a user equipment device 204 (hereinafter “UE 204” ) . The BS 202 includes a BS (base station) transceiver module 210, a BS antenna 212, a BS processor module 214, a BS memory module 216, and a network communication module 218, each module being coupled and interconnected with one another as necessary via a data communication bus 220. The UE 204 includes a UE (user equipment) transceiver module 230, a UE antenna 232, a UE memory module 234, and a UE processor module 236, each module being coupled and interconnected with one another as necessary via a data communication bus 240. The BS 202 communicates with the UE 204 via a communication channel 250, which can be any wireless channel or other medium suitable for transmission of data as described herein.
[0026] As would be understood by persons of ordinary skill in the art, system 200 may further include any number of modules other than the modules shown in FIG. 2. Those skilled in the art will understand that the various illustrative blocks, modules, circuits, and processing logic described in connection with the embodiments disclosed herein may be implemented in hardware, computer-readable software, firmware, or any practical combination thereof. To clearly illustrate this interchangeability and compatibility of hardware, firmware, and software, various illustrative components, blocks, modules, circuits, and steps are described generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware, or software can depend upon the particular application and design constraints imposed on the overall system. Those familiar with the concepts described herein may implement such functionality in a suitable manner for each particular application, but such implementation decisions should not be interpreted as limiting the scope of the present disclosure.
[0027] In accordance with some embodiments, the UE transceiver 230 may be referred to herein as an "uplink" transceiver 230 that includes a radio frequency (RF) transmitter and a RF receiver each comprising circuitry that is coupled to the antenna 232. A duplex switch (not shown) may alternatively couple the uplink transmitter or receiver to the uplink antenna in time duplex fashion. Similarly, in accordance with some embodiments, the BS transceiver 210 may be referred to herein as a "downlink" transceiver 210 that includes a RF transmitter and a RF receiver each comprising circuity that is coupled to the antenna 212. A downlink duplex switch may alternatively couple the downlink transmitter or receiver to the downlink antenna 212 in time duplex fashion. The operations of the two transceiver modules 210 and 230 may be coordinated in time such that the uplink receiver circuitry is coupled to the uplink antenna 232 for reception of transmissions over the wireless transmission link 250 at the same time that the downlink transmitter is coupled to the downlink antenna 212. Conversely, the operations of the two transceivers 210 and 230 may be coordinated in time such that the downlink receiver is coupled to the downlink antenna 212 for reception of transmissions over the wireless transmission link 250 at the same time that the uplink transmitter is coupled to the uplink antenna 232. In some embodiments, there is close time synchronization with a minimal guard time between changes in duplex direction.
[0028] The UE transceiver 230 and the base station transceiver 210 are configured to communicate via the wireless data communication link 250, and cooperate with a suitably configured RF antenna arrangement 212 / 232 that can support a particular wireless communication protocol and modulation scheme. In some illustrative embodiments, the UE transceiver 210 and the base station transceiver 210 are configured to support industry standards such as the Long Term Evolution (LTE) and emerging 5G standards, and the like. It is understood, however, that the present disclosure is not necessarily limited in application to a particular standard and associated protocols. Rather, the UE transceiver 230 and the base station transceiver 210 may be configured to support alternate, or additional, wireless data communication protocols, including future standards or variations thereof.
[0029] In accordance with various embodiments, the BS 202 may be an evolved node B (eNB) , a serving eNB, a target eNB, a femto station, or a pico station, for example. In some embodiments, the UE 204 may be embodied in various types of user devices such as a mobile phone, a smart phone, a personal digital assistant (PDA) , tablet, laptop computer, wearable computing device, etc. The processor modules 214 and 236 may be implemented, or realized, with a general purpose processor, a content addressable memory, a digital signal processor, an application specific integrated circuit, a field programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. In this manner, a processor may be realized as a microprocessor, a controller, a microcontroller, a state machine, or the like. A processor may also be implemented as a combination of computing devices, e.g., a combination of a digital signal processor and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a digital signal processor core, or any other such configuration.
[0030] Furthermore, the steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in firmware, in a software module executed by processor modules 214 and 236, respectively, or in any practical combination thereof. The memory modules 216 and 234 may be realized as RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. In this regard, memory modules 216 and 234 may be coupled to the processor modules 210 and 230, respectively, such that the processors modules 210 and 230 can read information from, and write information to, memory modules 216 and 234, respectively. The memory modules 216 and 234 may also be integrated into their respective processor modules 210 and 230. In some embodiments, the memory modules 216 and 234 may each include a cache memory for storing temporary variables or other intermediate information during execution of instructions to be executed by processor modules 210 and 230, respectively. Memory modules 216 and 234 may also each include non-volatile memory for storing instructions to be executed by the processor modules 210 and 230, respectively.
[0031] The network communication module 218 generally represents the hardware, software, firmware, processing logic, and / or other components of the base station 202 that enable bi-directional communication between base station transceiver 210 and other network components and communication nodes configured to communication with the base station 202. For example, network communication module 218 may be configured to support internet or WiMAX traffic. In a typical deployment, without limitation, network communication module 218 provides an 802.3 Ethernet interface such that base station transceiver 210 can communicate with a conventional Ethernet based computer network. In this manner, the network communication module 218 may include a physical interface for connection to the computer network (e.g., Mobile Switching Center (MSC) ) . The terms “configured for, ” “configured to” and conjugations thereof, as used herein with respect to a specified operation or function, refer to a device, component, circuit, structure, machine, signal, etc., that is physically constructed, programmed, formatted and / or arranged to perform the specified operation or function.
[0032] The Open Systems Interconnection (OSI) Model (referred to herein as, “open system interconnection model” ) is a conceptual and logical layout that defines network communication used by systems (e.g., wireless communication device, wireless communication node) open to interconnection and communication with other systems. The model is broken into seven subcomponents, or layers, each of which represents a conceptual collection of services provided to the layers above and below it. The OSI Model also defines a logical network and effectively describes computer packet transfer by using different layer protocols. The OSI Model may also be referred to as the seven-layer OSI Model or the seven-layer model. In some embodiments, a first layer may be a physical layer. In some embodiments, a second layer may be a Medium Access Control (MAC) layer. In some embodiments, a third layer may be a Radio Link Control (RLC) layer. In some embodiments, a fourth layer may be a Packet Data Convergence Protocol (PDCP) layer. In some embodiments, a fifth layer may be a Radio Resource Control (RRC) layer. In some embodiments, a sixth layer may be a Non Access Stratum (NAS) layer or an Internet Protocol (IP) layer, and the seventh layer being the other layer.
[0033] Various example embodiments of the present solution are described below with reference to the accompanying figures to enable a person of ordinary skill in the art to make and use the present solution. As would be apparent to those of ordinary skill in the art, after reading the present disclosure, various changes or modifications to the examples described herein can be made without departing from the scope of the present solution. Thus, the present solution is not limited to the example embodiments and applications described and illustrated herein. Additionally, the specific order or hierarchy of steps in the methods disclosed herein are merely example approaches. Based upon design preferences, the specific order or hierarchy of steps of the disclosed methods or processes can be re-arranged while remaining within the scope of the present solution. Thus, those of ordinary skill in the art will understand that the methods and techniques disclosed herein present various steps or acts in a sample order, and the present solution is not limited to the specific order or hierarchy presented unless expressly stated otherwise.
[0034] Systems and Methods for Enhancements related to Non-Terrestrial Network (NTN)
[0035] A self-organizing network (SON) , which may encompass solutions for network self-configuration and self-optimization, can be an automation technology designed to make the planning, configuration, management, optimization and healing of mobile radio access networks simpler and faster. The goal of SON technology is to achieve objectives of network self-configuration, self-optimization, and / or self-healing. Self-configuration may refer to an automated deployment of newly added network elements and a determination of appropriate parameter configurations for these elements. In an initial network deployment phase, self-configuration technology may enable plug-and-play deployment of base stations. As network operational data accumulates, self-optimization and self-healing can be achieved to some extent with assistance of artificial intelligence algorithms. Self-optimization may involve automatically optimizing various aspects such as coverage, capacity, and user perception while the network is running, without manual intervention. Examples may include load balancing, handover optimization, automatic neighbor relations, coverage and capacity optimization, inter-cell interference coordination, and energy savings. Self-healing may refer to an automation of fault management and fault correction processes to maintain a normal operation of the network.
[0036] Self-organizing network (SON) and minimization of drive test (MDT) functionalities supported by 5G NR may include mobility robustness optimization (MRO) , mobility load balancing (MLB) , random access channel (RACH) optimization, MDT, and / or L2 measurement. Mobility robustness optimization (MRO) may detect and correct mobility-related issues, including connection failures caused by intra-system or inter-system mobility, unnecessary inter-system handovers, and / or inter-system ping-pong handovers. MRO may also provide methods to differentiate these issues from new radio (NR) coverage-related problems and other mobility-unrelated issues. Mobility load balancing (MLB) may refer to the uniform distribution of load between cells and cell areas, transferring part of the traffic from congested cells or congested areas of cells, and / or removing part of the traffic from a cell, cell area, operator, or different system, to achieve network energy saving.
[0037] A minimization of drive-test (MDT) may primarily involve obtaining relevant parameters needed for network optimization by either reporting measurement reports from mobile terminals or collecting measurement results from a base station side, aiming to reduce the operational costs of network optimization and maintenance for operators. Compared to traditional drive tests, the MDT offers advantages such as energy saving, reduced drive test expenses, and shortened optimization cycles, resulting in higher user satisfaction. Additionally, the MDT can collect measurement information from entire areas (e.g., narrow roads, forests, private premises) that traditional drive tests cannot capture.
[0038] Considering the tangible commercial interests and the stability and technological maturity, enhancements to SON / MDT for certain new features are being considered, such as, MRO enhancement for lower-layer triggered mobility (LTM) , conditional handover (CHO) with candidate secondary cell groups (SCGs) and subsequent conditional primary cell of a SCG (pScell) addition and change (CPAC) , SON / MDT enhancements for intra NTN mobility, and / or network slicing.
[0039] From the perspective of global network coverage, more than 80%of land areas and 95%of sea areas are not covered by ground cellular networks. The 5G network can be built not only to provide high network speeds, but also ubiquitous mobile network access. However, in remote areas such as mountainous areas, deserts, and the ocean, building and maintaining a 5G terrestrial network can be extremely expensive, which makes it impossible to provide 5G network coverage in those areas. Fortunately, the development of aerospace technology enables the satellite-based broadband communication system to provide radio coverage to large or even global areas at a much lower cost. As such, the 5G network can deeply integrate with the satellite communication system to constitute a convergent communication network that provides seamless coverage on the planet, meeting various service requirements anywhere in the world.
[0040] A non-terrestrial network (NTN) can be a terminal-satellite direct communication technology based on the new radio (NR) interface technology and can be also an important supplement to terrestrial cellular communication technology. With the integration of the satellite communication network and the ground 5G network, the NTN can provide ubiquitous coverage without being restricted by terrain and landform, and connect the sky, earth, sea, and other spaces to form an integrated ubiquitous access network that enables on-demand access in all scenarios. It can be seen that non-terrestrial networks (NTN) have been studied, but SON and MDT functions currently do not account for potential NTN deployments. Supporting the MRO for NTN can be beneficial, particularly in addressing mobility issues related to NTN, such as time-based and / or location-based CHO. The present application provides possible solutions on how to support the SON / MDT for NTN.
[0041] How to indicate that cells are NTN cells
[0042] The user equipment (UE) may send an uplink (UL) message to the gNB or the base station. The UL message may comprise information related to a non-terrestrial network (NTN) .
[0043] In some embodiments, the information can be included in at least one of: a radio link failure report when a radio link failure is detected; a successful handover report when a successful handover is detected; a report of logged measurement results; a report of the connection failure; a successful PSCell change or addition report; a report of mobility history information or a new report that is stored when a satellite switch procedure is performed.
[0044] In certain embodiments, the UE may receive a request for the UL message from the gNB or BS. The UE may send the UL message according to the request to the gNB or BS.
[0045] In some embodiments, the information may include an indication that a cell related to at least one of the wireless communication device or the wireless communication node, is part of the NTN. The information may comprise at least one of: frequency information of the cell, or an indication of whether the cell is part of the NTN.
[0046] In some embodiments, the cell may comprise at least one of: a serving cell that performs a logged measurement in a logged measurement report; at least one neighbor cell that performs the logged measurement in the logged measurement report; a cell at which the last measurement results was taken, where connection establishment failure or connection resume failure happened in a connection failure report; at least one neighbor cell at which the last measurement results was taken, where connection establishment failure or connection resume failure happened in a connection failure report; a primary cell (PCell) in which radio link failure (RLF) is detected or a target PCell of a failed handover in a radio link failure report; at least one candidate target cell for conditional handover at a time of connection failure in a radio link failure report; a candidate target cell for conditional handover that the wireless communication device selected for conditional handover (CHO) in a radio link failure report; a PCell in which radio link failure (RLF) is detected or a source PCell of a failed handover in an evolved universal terrestrial radio access (E-UTRA) radio link failure report; at least one neighbor E-UTRA cell that the last measurement results were taken, when radio link failure or handover failure happened in a radio link failure report; at least one neighbor new radio (NR) cell that the last measurement results were taken, when radio link failure or handover failure happened in a radio link failure report; a source PCell of a last handover in a radio link failure report; a PCell in which the wireless communication device failed to perform fast master cell group (MCG) recovery procedure or the wireless communication device successfully performed fast MCG recovery procedure in a radio link failure report; a cell in which the wireless communication device comes back to connected after connection failure and after failing to perform reestablishment in a radio link failure report; a cell in which a re-establishment attempt was made after connection failure in a radio link failure report; a target PCell of a handover for which a successful handover report was generated in a successful handover report; a target E-UTRA PCell of a handover in which the successful handover triggers a successful handover report; at least one neighboring NR cell that the last measurement results were taken when a successful handover is executed in a successful handover report; a source PCell of a handover in which the successful handover triggers a successful handover report; a target PCell of a handover in which the successful handover triggers a successful handover report; at least one neighbor cell that the last measurement was taken when a successful primary cell of a secondary cell group (SCG) (PSCell) change or addition is executed; a PCell to which the wireless communication device was connected when a successful PSCell change or addition in a successful PSCell report; a source PSCell of a PSCell change in which a successful PSCell change in a successful PSCell report; a target PSCell of a PSCell change in which the successful PSCell change in a successful PSCell report; or a recently visited cell in mobility history information.
[0047] In a current report (e.g., radio link failure (RLF) report, successful handover report (SHR) report, connection failure report (connEstFailReport) , logged mesaurement report (logMeasReport) , SuccessPSCell report) , only the cell identity (ID) can be used to indicate identity characteristics of a cell. To indicate that the cells in the report are NTN cells, the frequency information (e.g., carrierFreq IE) can be also added in the report to indicate identity characteristics of a cell.
[0048] The RLF report may include / record information about multiple cells, including a source cell of a last handover (previousPCellId IE) , a cell where RLF was detected (failedPCellId IE) , a cell where reconnection occurred (reconnectCellId IE) , a cell where re-establishment occurred (reestablishmentCellId IE) , cells related to CHO (choCellId IE) , and / or the pScell where the UE performs master cell group (MCG) recovery (pSCellId IE) . To indicate whether these cells are NTN cells, relevant frequency information (e.g., carrierFreq IE) can be provided along with the cell ID in a message.
[0049] The SHR report may include / record some information about multiple cells, including a source PCell of a successful handover (sourcePCellId IE) , and / or a target PCell of a successful handover (targetPCellId IE) . To indicate whether these cells are NTN cells, relevant frequency information (e.g., carrierFreq IE) can be provided along with the cell ID in a message.
[0050] The ConnEstFail report may include / record the last measurement results taken in the cell, to indicate that the cell is an NTN cell, the frequency information (e.g., carrierFreq IE) can be provided. In some embodiments, to indicate the cell is an NTN cell, the frequency information (e.g., carrierFreq IE) can be provided together with the cell identifier in a LogMeas report and a SuccessPSCell report.
[0051] In some embodiments, an indication (e.g., 1 bit information) regarding whether the cell is an NTN cell can be added in the report. In a current report (e.g., RLF report, SHR report, ConnEstFail Report, LogMeas Report, SuccessPSCell Report) , only the cell ID can be used to indicate the identity characteristics of a cell. To indicate the cells in the report are NTN cells, an indication regarding whether the cell is an NTN cell can be added in the report.
[0052] The RLF report may include / record information about multiple cells, including a source cell of the last handover (previousPCellId IE) , a cell where RLF was detected (failedPCellId IE) , a cell where reconnection occurred (reconnectCellId IE) , a cell where re-establishment occurred (reestablishmentCellId IE) , cells related to CHO (choCellId IE) , and / or the pScell where UE performs MCG recovery (pSCellId IE) . To indicate whether these cells are NTN cells, relevant indication regarding whether the cell is an NTN cell can be provided along with the cell ID in a message.
[0053] The SHR report may include / record some information about multiple cells, including a source PCell of a successful handover (sourcePCellId IE) , and / or a target PCell of a successful handover (targetPCellId IE) . To indicate whether these cells are NTN cells, relevant indication regarding whether the cell is an NTN cell can be provided along with the cell ID in a message.
[0054] The ConnEstFail report may include / record the last measurement results taken in the cell, to indicate the cell is an NTN cell, the indication regarding whether the cell is an NTN cell can be provided. To indicate that the cell is an NTN cell, the indication regarding whether the cell is an NTN cell can be provided together with the cell identifier in the LogMeas report and the SuccessPSCell report.
[0055] NTN configuration for self-optimization
[0056] The user equipment (UE) may send an uplink (UL) message to the gNB or the base station. The UL message may comprise information related to a non-terrestrial network (NTN) . To help network self-optimization, the information may include at least one NTN related measurement parameter.
[0057] In some embodiments, the information can be included in at least one of: a radio link failure report when a radio link failure is detected; a successful handover report when a successful handover is detected; a report of logged mesaurement results; a report of the connection failure; a successful PSCell change or addition report; a report of mobility history information or a new report that is stored when a satellite switch procedure is performed.
[0058] In certain embodiments, the UE may receive a request for the UL message from the gNB or BS. The UE may send the UL message according to the request to the gNB or BS.
[0059] In some embodiments, the at least one NTN related measurement parameter may comprise at least one of: an indication of a type of a NTN related measurement that is performed in RRC_IDLE state and / or RRC_INACTIVE state, wherein the NTN related measurement is a location-based measurement or a time-based measurement; an indication of a distance threshold that is used in location-based measurement initiation in RRC_IDLE state and / or RRC_INACTIVE state; an indication of a reference location of a serving cell at a time reference that is used in location-based measurement initiation in RRC_IDLE state and / or RRC_INACTIVE state; a list of terrestrial network (TN) coverage area information that is used to assist skipping TN measurements for NTN user equipment (UEs) in RRC_IDLE and / or RRC_INACTIVE state; or time information regarding when a cell provided by an NTN system ceases serving the area the cell is currently covering.
[0060] In some embodiments, the information may include at least one NTN related parameter. The at least one NTN related parameter may comprise at least one of: time information regarding when a cell provided by an NTN system ceases serving the area the cell is currently covering; an indication of whether a last executed handover was an intra-NTN handover; an indication of whether a connection failure is due to a failure in an intra-NTN handover or an intra-NTN radio link; or a list of NTN neighbor cells.
[0061] In some embodiments, a type / indication / parameter can be added to the RLF report regarding whether the last executed handover before the last detected connection failure was an intra-NTN handover. For example, a value can be added in the lastHO-Type IE. If the field is set the value (e.g., ntnho) , the last executed handover can be between NTN cells. In some embodiments, some types / indications / parameters can be added to the RLF report regarding whether the connected failure is due to an intra-NTN radio link failure or intra-NTN handover failure. In some embodiments, some values / indications can be added in a connectionFailureType IE.If the field is set the value (e.g., ntnrlf, ntnhof) , the connected failure can be due to the intra-NTN radio link failure or intra-NTN handover failure.
[0062] In some embodiments, since the measurement results in RRC_IDLE state and / or RRC_INACTIVE state may be included in a logged measurement report, to help gNB with network optimization, the information about measurement results in RRC_IDLE state and / or RRC_INACTIVE state for NTN cells may be contained in a logged measurement report in the UL message.
[0063] In some embodiments, an indication of a type of a NTN related measurement that is performed in RRC_IDLE state and / or RRC_INACTIVE state. The NTN related measurement can be a location-based measurement or a time-based measurement.
[0064] In some embodiments, an indication of a distance threshold that is used in a location-based measurement initiation in RRC_IDLE state and / or RRC_INACTIVE state can be carried from UE to the network in the UL message.
[0065] In some embodiments, an indication of a reference location of a serving cell of an NTN earth moving system at a time reference that is used in location-based measurement initiation in RRC_IDLE state and / or RRC_INACTIVE state can be carried from UE to the network in the UL message.
[0066] In some embodiments, an indication of a reference location of a serving cell provided via an NTN quasi-earth fixed system at a time reference that is used in location-based measurement initiation in RRC_IDLE state and / or RRC_INACTIVE state can be carried from UE to the network in the UL message.
[0067] In some embodiments, a list of terrestrial network (TN) coverage area information that is used to assist skipping TN measurements for NTN user equipment (UEs) in RRC_IDLE and / or RRC_INACTIVE state can be carried from UE to the network in the UL message. For example, a reference location and a distance radius from the reference location can be used to define a TN coverage area.
[0068] In some embodiments, time information regarding when a cell provided by an NTN system ceases serving the area the cell is currently covering can be carried from UE to the network in the UL message.
[0069] In some embodiments, at least one parameter for the UE to access NR via NTN access can be carried from UE to the network in the UL message. The at least one parameter can be comprising at least one of: Ephemeris data, common TA parameters, k_offset, or validity duration for UL synchronization information and epoch. In some embodiments, a list of NTN neighbor cells including ntn-Config, carrier frequency, and / or PhysCellId, can be carried from UE to the network in the UL message.
[0070] Satellite information
[0071] The user equipment (UE) may send an uplink (UL) message to the gNB or the base station. The UL message may comprise information related to a non-terrestrial network (NTN) . The information may include satellite information.
[0072] In some embodiments, the information can be included in at least one of: a radio link failure report when a radio link failure is detected; a successful handover report when a successful handover is detected; a report of logged mesaurement results; a report of the connection failure; a successful PSCell change or addition report; a report of mobility history information or a new report that is stored when a satellite switch procedure is performed.
[0073] In certain embodiments, the UE may receive a request for the UL message from the gNB or BS. The UE may send the UL message according to the request to the gNB or BS.
[0074] In some embodiments, the satellite information may comprise at least one of: an indication of an absolute time when a satellite is going to start serving a cell, ephemeris information of a satellite when a satellite is going to start serving a cell, the epoch time of a satellite for the NTN assistance information of a cell.
[0075] In some embodiments, the cell may comprise at least one of: a serving cell that performs a logged measurement in a logged measurement report; at least one neighbor cell that performs the logged measurement in the logged measurement report; a cell at which the last measurement results was taken, where connection establishment failure or connection resume failure happened in a connection failure report; at least one neighbor cell at which the last measurement results was taken, where connection establishment failure or connection resume failure happened in a connection failure report; a primary cell (PCell) in which radio link failure (RLF) is detected or a target PCell of a failed handover in a radio link failure report; at least one candidate target cell for conditional handover at a time of connection failure in a radio link failure report; a candidate target cell for conditional handover that the wireless communication device selected for conditional handover (CHO) in a radio link failure report; a PCell in which radio link failure (RLF) is detected or a source PCell of a failed handover in an evolved universal terrestrial radio access (E-UTRA) radio link failure report; at least one neighbor E-UTRA cell that the last measurement results were taken, when radio link failure or handover failure happened in a radio link failure report; at least one neighbor new radio (NR) cell that the last measurement results were taken, when radio link failure or handover failure happened in a radio link failure report; a source PCell of a last handover in a radio link failure report; a PCell in which the wireless communication device failed to perform fast master cell group (MCG) recovery procedure or the wireless communication device successfully performed fast MCG recovery procedure in a radio link failure report; a cell in which the wireless communication device comes back to connected after connection failure and after failing to perform reestablishment in a radio link failure report; a cell in which a re-establishment attempt was made after connection failure in a radio link failure report; a target PCell of a handover for which a successful handover report was generated in a successful handover report; a target E-UTRA PCell of a handover in which the successful handover triggers a successful handover report; at least one neighboring NR cell that the last measurement results were taken when a successful handover is executed in a successful handover report; a source PCell of a handover in which the successful handover triggers a successful handover report; a target PCell of a handover in which the successful handover triggers a successful handover report; at least one neighbor cell that the last measurement was taken when a successful primary cell of a secondary cell group (SCG) (PSCell) change or addition is executed; a PCell to which the wireless communication device was connected when a successful PSCell change or addition in a successful PSCell report; a source PSCell of a PSCell change in which a successful PSCell change in a successful PSCell report; a target PSCell of a PSCell change in which the successful PSCell change in a successful PSCell report; or a recently visited cell in mobility history information.
[0076] In some embodiments, Ephemeris can be represented in the format of position and velocity state vectors in the earth-centered earth-fixed (ECEF) coordinate system, or in the format of orbital parameters in the earth-centered inertial (ECI) coordinate system.
[0077] In some embodiments, the epoch time of the satellite can be provided by SIB1 message before. The epoch time may comprise a starting time of a DL sub-frame, indicated by a system frame number (SFN) and a sub-frame number signaled together with the assistance information in a message.
[0078] The information for time-based / location-based CHO
[0079] The user equipment (UE) may send an uplink (UL) message to the gNB or the base station. The UL message may comprise information related to a non-terrestrial network (NTN) . Since NTN supports time-based CHO and location-based CHO, to help network optimization, the information may include time-based conditional handover (CHO) information or location-based CHO information.
[0080] In some embodiments, the information can be included in at least one of: a radio link failure report when a radio link failure is detected; a successful handover report when a successful handover is detected; a report of logged mesaurement results; a report of the connection failure; a report of mobility history information or a new report that is stored when a satellite switch procedure is performed.
[0081] In certain embodiments, the UE may receive a request for the UL message from the gNB or BS. The UE may send the UL message according to the request to the gNB or BS.
[0082] In some embodiments, the time-based information may comprise at least one of: an indication of an absolute time when a radio link failure (RLF) or handover failure is caused by time-based CHO; an indication of the absolute time when a successful handover is detected by time-based CHO; an indication of a time threshold that is used for time-based CHO; an indication of a duration that is used for defining a leaving condition for time-based CHO; an indication of a last executed handover before a last detected connection failure is a time-based CHO; an indication of a last executed handover before a last detected connection failure is a time-based CHO that is performed via random access channel (RACH) -less; an indication of whether a connected failure is due to a time-based CHO; or an indication of whether a connected failure is due to a time-based CHO that is performed via RACH-less.
[0083] In some embodiments, the location-based CHO information may comprise at least one of:an indication of a location of the wireless communication device when a radio link failure (RLF) or handover failure is caused by location-based CHO; an indication of a location of the wireless communication device when a successful handover is detected by location-based CHO; an indication of coarse location of the wireless communication device when a radio link failure (RLF) or handover failure is caused by location-based CHO; an indication of coarse location of the wireless communication device when a successful handover is detected by location-based CHO; an indication of one or more reference locations that are used for location-based CHO; an indication of one or more distance thresholds that are used for location-based CHO; an indication of a distance between the wireless communication device and the one or more reference locations when the RLF, the handover failure, or the successful handover is detected by location-based CHO; an indication of a last executed handover before a last detected connection failure is a location-based CHO; or an indication of whether a connected failure is due to a location-based CHO.
[0084] In some embodiments, the location information may comprise at least one of: a location estimate using one of the geographic shapes, a velocity estimate using one of the velocity shapes, the UTC time when the location estimate is valid.
[0085] In some embodiments, the coarse location information may contains the Latitude degrees and longitude degrees information. The coarse location information may meet the granularity accuracy requirement of approximately 2 kilometers.
[0086] In some embodiments, reference locations that are used for location-based CHO can be carried from UE to the network in the UL message. The reference locations can be used for condEventD1 and condEventD2. There can be two kinds of reference locations. One can be associated to a serving cell (e.g., referenceLocation1) and the other can be associated to a candidate target cell (e.g., referenceLocation2) .
[0087] In some embodiments, distance thresholds that are used for location-based CHO can be carried from UE to the network in the UL message. There can be two kinds of distance thresholds. One (e.g., distanceThreshFromReference1) can be used to compare the distance between UE and a reference location (e.g., referenceLocation1) . The other (e.g., distanceThreshFromReference2) can be used to compare the distance between UE and a reference location (e.g., referenceLocation2) .
[0088] In some embodiments, a distance between UE and a reference location (e.g., referencelocation1) when the radio link failure or / and handover failure or / and successful handover is detected by location-based CHO can be carried from UE to the network in the UL message. In some embodiments, a distance between UE and a reference location (e.g., referencelocation2) when the radio link failure or / and handover failure or / and successful handover is detected by location-based CHO can be carried from UE to the network in the UL message.
[0089] RACH-less handover for NTN
[0090] The user equipment (UE) may send an uplink (UL) message to the gNB or the base station. The UL message may comprise information related to a non-terrestrial network (NTN) . Since NTN system supports RACH-less handover, to help network optimisation, the information may include random access channel (RACH) -less handover information.
[0091] In some embodiments, the information can be included in at least one of: a radio link failure report when a radio link failure is detected; a successful handover report when a successful handover is detected; a report of logged mesaurement results; a report of the connection failure; or a new report that is stored when a satellite switch procedure is performed.
[0092] In certain embodiments, the UE may receive a request for the UL message from the gNB or BS. The UE may send the UL message according to the request to the gNB or BS.
[0093] The RACH-less handover information may comprise at least one of: an indication of a last executed handover being a RACH-less handover; an indication of whether a connected failure is due to a RACH-less handover failure; or at least one RACH-less handover related parameter. In some embodiments, the at least one RACH-less handover related parameter may comprise at least one of: an indication of reference signal received power (RSRP) for synchronization signal block (SSB) selection for a pre-allocated uplink grant; an initial value of a configured grant retransmission timer used for an initial uplink transmission of the RACH-less handover; a set of demodulation reference signal (DMRS) ports for SSB to physical uplink shared channel (PUSCH) mapping for the RACH-less handover; a number of DMRS sequences for SSB to PUSCH mapping for the RACH-less handover; a threshold of the RSRP configured for SSB selection for the pre-allocated uplink grant for the RACH-less handover; a number of SSBs per pre-allocated uplink grant PUSCH for the RACH-less handover; or a SSB subset for SSB to configured grant (CG) PUSCH mapping within a CG configuration for the RACH-less handover.
[0094] In some embodiments, a type / indication / parameter of the last executed handover before the last detected connection failure can be added in the RLF report. Since a RACH-less HO is supported for an NTN system, a type / indication / parameter of the last executed handover about RACH-less HO can be added in the RLF report. For example, a value / indication / parameter can be added in the lastHO-Type IE. If the field is set the value (e.g., rachlessho) , the last executed handover can be a RACH-less handover.
[0095] In some embodiments, a type / indication / parameter can be added to the RLF report regarding whether the connected failure is due to a RACH-less handover failure. For example, a value can be added in the connectionFailureType IE. If the field is set the value (e.g., rachlessho) , the connected failure can be due to a RACH-less handover failure.
[0096] In some embodiments, the parameters of RACH-less handover can be recorded in the RLF report. In some embodiments, a reference signal received power (RSRP) for SSB selection for the pre-allocated uplink grant can be carried from the UE to the network in the UL message. In some embodiments, an initial value of the configured grant retransmission timer used for the initial uplink transmission of RACH-less handover can be carried from the UE to the network in the UL message.
[0097] In some embodiments, a set of demodulation reference signal (DMRS) ports for SSB to physical uplink shared channel (PUSCH) mapping for RACH-less handover can be carried from the UE to the network in the UL message. In some embodiments, a number of DMRS sequences for SSB to PUSCH mapping for RACH-less handover can be carried from the UE to the network in the UL message. In some embodiments, a RSRP threshold configured for SSB selection for the pre-allocated uplink grant for RACH-less handover can be carried from the UE to the network in the UL message. In some embodiments, a number of SSBs per pre-allocated uplink grant PUSCH for RACH-less handove can be carried from the UE to the network in the UL message. In some embodiments, a SSB subset for SSB to CG PUSCH mapping within one CG configuration for RACH-less handover can be carried from the UE to the network in the UL message.
[0098] Satellite switch with re-synchronization
[0099] The user equipment (UE) may send an uplink (UL) message to the gNB or the base station. The UL message may comprise information related to a non-terrestrial network (NTN) . Satellite switch procedure may be performed in NTN system, but there is no related information in the message from UE to network for network optimization. To help gNB optimize the procedure of satellite switch, the information regarding a satellite switch procedure may be included in the UL message.
[0100] In some embodiments, the information can be included in at least one of: a radio link failure report when a radio link failure is detected; a successful handover report when a successful handover is detected; a report of mobility history information or a new report that is stored when a satellite switch procedure is performed.
[0101] In certain embodiments, the UE may receive a request for the UL message from the gNB or BS. The UE may send the UL message according to the request to the gNB or BS.
[0102] In some embodiments, the information regarding the satellite switch procedure may comprise at least one of: an indicator if a random access procedure is initiated for the satellite switch with a re-synchronization procedure; a cause of radio link failure (RLF) to indicate whether the RLF is due to a consecutive satellite switch with a re-synchronization procedure; or at least one parameter regarding the satellite switch with a re-synchronization procedure.
[0103] In some embodiments, the at least one parameter regarding the satellite switch with a re-synchronization procedure may comprise at least one of: an indication of a time since a last satellite switch with a re-synchronization execution until a loss of UL synchronization due to the satellite switch with a re-synchronization procedure; an indication of an absolute time when the UL synchronization is lost due to the satellite switch with a re-synchronization procedure; an indication of a validity duration for NTN related assistance information; a number of latest consecutive satellite switch with a re-synchronization procedure failure; an indication of an absolute time when the satellite switch with a re-synchronization procedure is obtained; an indication of a time since a first loss of UL synchronization due to the satellite switch with the re- synchronization procedure until the UL synchronization is obtained; or an indication of a physical cell identifier (PCI) of a source satellite; an indication of a PCI of a target satellite; an indication of a type of satellite switch that is a soft satellite switch; an indication of a type of satellite switch that is a hard satellite switch; an indication of whether the satellite switch is performed via a re-synchronization procedure; a time offset between the SSB from source and target satellite at the uplink time synchronization reference point; time information on when the target satellite is going to start serving the area currently covered by the serving satellite; the time information on when a cell provided via NTN system is going to stop serving the area the cell is currently covering; or an indicator of whether the satellite switch is performed via a re-synchronization procedure without random access procedure.
[0104] In some embodiments, the information may include a cause of radio link failure (RLF) to indicate whether the RLF is due to a satellite switch with a re-synchronization procedure. In some embodiments, a RLF cause can be added to the RLF report regarding whether the radio link failure is due to the satellite switch with re-sync procedure. For example, a RLF cause can be added in the rlf-Cause IE. If the field is set the value (e.g., satelliteswitchresync) , the radio link failure can be due to the satellite switch with a re-synchronization procedure.
[0105] In some embodiments, the information may introduce a new indicator for which the RA report is triggered. For example, a new indicator (e.g., satelliteswitch) is used in case of satellite switch with re-synchronization related RA procedure in the cell.
[0106] A duration of stay in an NTN cell
[0107] The user equipment (UE) may send an uplink (UL) message to the gNB or the base station. The UL message may comprise information related to a non-terrestrial network (NTN) . Since the size of NTN cells is much larger than the size of TN cells, the duration of stay in an NTN cell may be much longer than that in an TN cell. To help gNB optimise the configuration for NTN cells, the duration of stay in an NTN cell may be included in the UL message.
[0108] In some embodiments, the information can be included in at least one of: a radio link failure report when a radio link failure is detected; a successful handover report when a successful handover is detected; a report of logged measurement results; a report of the connection failure; a report of mobility history information or a new report that is stored when a satellite switch procedure is performed.
[0109] In certain embodiments, the UE may receive a request for the UL message from the gNB or BS. The UE may send the UL message according to the request to the gNB or BS.
[0110] In some embodiments, the information includes a duration of stay in an NTN cell.
[0111] Area configuration for logged MDT
[0112] A user equipment (UE) may receive configuration information for optimizing network performance from a gNB or a base station. Since the size of NTN cell is much larger than TN cell, considering energy saving, the area configuration for logged measurement may be enhanced. In certain embodiments, the user equipment (UE) may send an uplink (UL) message to the gNB or the base station after or before receiving the configuration information. The UL message may comprise information related to a non-terrestrial network (NTN) .
[0113] In some embodiments, the configuration information may include a logged measurement configuration for at least one NTN cell. The logged measurement configuration may comprise at least one of: a list of tracking area codes for a tracking area identity in area configuration for logged measurement; an area configuration for an NTN system, wherein the area configuration includes a reference location and a distance threshold; or at least one coordinate point to mark area configuration for logged measurement. The present application provides an area configuration for an NTN system. There can be a reference location and a distance threshold. When the distance between the UE and the reference location is shorter than the distance threshold, the UE can perform the logged measurement. The present application provides one or more coordinate points to mark an area configuration for logged measurement. In certain embodiments, the present application provides an area configuration for NTN system. There can be a reference location and a distance threshold. When the distance between the UE and the reference location is shorter than the distance threshold, the UE may skip the logged measurement.
[0114] In some embodiments, different from a terrestrial network, the network may broadcast multiple tracking area codes (TACs) per public land mobile network (PLMN) in an NR NTN cell. In legacy, the tracking area identity may comprise a PLMN identity and a tracking area code in area configuration for a logged MDT, which may not be suitable for non-terrestrial network (NTN) systems.
[0115] In some embodiments, a tracking area code list for tracking area identity in the area configuration for logged MDT can be introduced. The tracking area identity may comprise a PLMN identity and a list of tracking area codes. In some embodiments, a list of tracking area code for the measured cell can be included / recorded in the logged MDT report.
[0116] It should be understood that one or more features from the above / following implementation examples are not exclusive to the specific implementation examples, but can be combined in any manner (e.g., in any priority and / or order, concurrently or otherwise) .
[0117] FIG. 3 illustrates a flow diagram of a method 300 for self-organizing networks (SON) and / or minimization of drive test (MDT) enhancements for intra -non-terrestrial network (NTN) mobility. The method 300 may be implemented using any one or more of the components and devices detailed herein in conjunction with FIGs. 1–2. In overview, the method 300 may be performed by a UE, in some embodiments. Additional, fewer, or different operations may be performed in the method 300 depending on the embodiment. At least one aspect of the operations is directed to a system, method, apparatus, or a computer-readable medium.
[0118] A wireless communication device (e.g., a user equipment (UE) ) may send an uplink (UL) message (e.g., UEinformationresponse message) to a wireless communication node (e.g., a gNB or a base station (BS) ) . The UL message may comprise information related to a non-terrestrial network (NTN) . In some embodiments, the wireless communication device (e.g., a user equipment (UE) ) may receive configuration information (e.g., LoggedMeasurementConfiguration) for optimizing network performance from the wireless communication node (e.g., a gNB or a base station (BS) ) .
[0119] In some embodiments, the information may include an indication that a cell related to at least one of the wireless communication device or the wireless communication node, is part of the NTN. In some embodiments, the information may comprise at least one of: frequency information of the cell, or an indication of whether the cell is part of the NTN. In some embodiments, the cell may comprise at least one of: a serving cell that performs a logged measurement in a logged measurement report; at least one neighbor cell that performs the logged measurement in the logged measurement report; a cell at which the last measurement results was taken, where connection establishment failure or connection resume failure happened in a connection failure report; at least one neighbor cell at which the last measurement results was taken, where connection establishment failure or connection resume failure happened in a connection failure report; a primary cell (PCell) in which radio link failure (RLF) is detected or a target PCell of a failed handover in a radio link failure report; at least one candidate target cell for conditional handover at a time of connection failure in a radio link failure report; a candidate target cell for conditional handover that the wireless communication device selected for conditional handover (CHO) in a radio link failure report; a PCell in which radio link failure (RLF) is detected or a source PCell of a failed handover in an evolved universal terrestrial radio access (E-UTRA) radio link failure report; at least one neighbor E-UTRA cell that the last measurement results were taken, when radio link failure or handover failure happened in a radio link failure report; at least one neighbor new radio (NR) cell that the last measurement results were taken, when radio link failure or handover failure happened in a radio link failure report; a source PCell of a last handover in a radio link failure report; a PCell in which the wireless communication device failed to perform fast master cell group (MCG) recovery procedure or the wireless communication device successfully performed fast MCG recovery procedure in a radio link failure report; a cell in which the wireless communication device comes back to connected after connection failure and after failing to perform reestablishment in a radio link failure report; a cell in which a re-establishment attempt was made after connection failure in a radio link failure report; a target PCell of a handover for which a successful handover report was generated in a successful handover report; a target E-UTRA PCell of a handover in which the successful handover triggers a successful handover report; at least one neighboring NR cell that the last measurement results were taken when a successful handover is executed in a successful handover report; a source PCell of a handover in which the successful handover triggers a successful handover report; a target PCell of a handover in which the successful handover triggers a successful handover report; at least one neighbor cell that the last measurement was taken when a successful primary cell of a secondary cell group (SCG) (PSCell) change or addition is executed; a PCell to which the wireless communication device was connected when a successful PSCell change or addition in a successful PSCell report; a source PSCell of a PSCell change in which a successful PSCell change in a successful PSCell report; a target PSCell of a PSCell change in which the successful PSCell change in a successful PSCell report; or a recently visited cell in mobility history information.
[0120] In some embodiments, the information may include at least one NTN related measurement parameter. The at least one NTN related measurement parameter may comprise at least one of: an indication of a type of a NTN related measurement that is performed in RRC_IDLE state and / or RRC_INACTIVE state, wherein the NTN related measurement is a location-based measurement or a time-based measurement; an indication of a distance threshold that is used in location-based measurement initiation in RRC_IDLE state and / or RRC_INACTIVE state; an indication of a reference location of a serving cell at a time reference that is used in location-based measurement initiation in RRC_IDLE state and / or RRC_INACTIVE state; a list of terrestrial network (TN) coverage area information that is used to assist skipping TN measurements for NTN user equipment (UEs) in RRC_IDLE and / or RRC_INACTIVE state; or time information regarding when a cell provided by an NTN system ceases serving the area the cell is currently covering.
[0121] In some embodiments, the information may include at least one NTN related parameter. The at least one NTN related parameter may comprise at least one of: time information regarding when a cell provided by an NTN system ceases serving the area the cell is currently covering; an indication of whether a last executed handover was an intra-NTN handover; an indication of whether a connection failure is due to a failure in an intra-NTN handover or an intra-NTN radio link; or a list of NTN neighbor cells.
[0122] In some embodiments, the information may include time-based conditional handover (CHO) information or location-based CHO information. In some embodiments, the time-based information may comprise at least one of: an indication of an absolute time when a radio link failure (RLF) or handover failure is caused by time-based CHO; an indication of the absolute time when a successful handover is detected by time-based CHO; an indication of a time threshold that is used for time-based CHO; an indication of a duration that is used for defining a leaving condition for time-based CHO; an indication of a last executed handover before a last detected connection failure is a time-based CHO; an indication of a last executed handover before a last detected connection failure is a time-based CHO that is performed via random access channel (RACH) -less; an indication of whether a connected failure is due to a time-based CHO; or an indication of whether a connected failure is due to a time-based CHO that is performed via RACH-less. In some embodiments, the location-based CHO information may comprise at least one of: an indication of a location of the wireless communication device when a radio link failure (RLF) or handover failure is caused by location-based CHO; an indication of a location of the wireless communication device when a successful handover is detected by location-based CHO; an indication of coarse location of the wireless communication device when a radio link failure (RLF) or handover failure is caused by location-based CHO; an indication of coarse location of the wireless communication device when a successful handover is detected by location-based CHO; an indication of one or more reference locations that are used for location-based CHO; an indication of one or more distance thresholds that are used for location-based CHO; an indication of a distance between the wireless communication device and the one or more reference locations when the RLF, the handover failure, or the successful handover is detected by location-based CHO; an indication of a last executed handover before a last detected connection failure is a location-based CHO; or an indication of whether a connected failure is due to a location-based CHO.
[0123] In some embodiments, the configuration information may include a logged measurement configuration for at least one NTN cell. The logged measurement configuration may comprise at least one of: a list of tracking area codes for a tracking area identity in area configuration for logged measurement; an area configuration for an NTN system, wherein the area configuration includes a reference location and a distance threshold; or at least one coordinate point to mark area configuration for logged measurement. The present application provides an area configuration for an NTN system. There can be a reference location and a distance threshold. When the distance between the UE and the reference location is shorter than the distance threshold, the UE can perform the logged measurement. The present application provides one or more coordinate points to mark an area configuration for logged measurement. In certain embodiments, the present application provides an area configuration for NTN system. There can be a reference location and a distance threshold. When the distance between the UE and the reference location is shorter than the distance threshold, the UE may skip the logged measurement.
[0124] In some embodiments, the information may include random access channel (RACH) -less handover information. The RACH-less handover information may comprise at least one of: an indication of a last executed handover being a RACH-less handover; an indication of whether a connected failure is due to a RACH-less handover failure; or at least one RACH-less handover related parameter.
[0125] In some embodiments, the at least one RACH-less handover related parameter may comprise at least one of: an indication of reference signal received power (RSRP) for synchronization signal block (SSB) selection for a pre-allocated uplink grant; an initial value of a configured grant retransmission timer used for an initial uplink transmission of the RACH-less handover; a set of demodulation reference signal (DMRS) ports for SSB to physical uplink shared channel (PUSCH) mapping for the RACH-less handover; a number of DMRS sequences for SSB to PUSCH mapping for the RACH-less handover; a threshold of the RSRP configured for SSB selection for the pre-allocated uplink grant for the RACH-less handover; a number of SSBs per pre-allocated uplink grant PUSCH for the RACH-less handover; or a SSB subset for SSB to configured grant (CG) PUSCH mapping within a CG configuration for the RACH-less handover.
[0126] In some embodiments, the information may include information regarding a satellite switch procedure. In some embodiments, the information regarding the satellite switch procedure may comprise at least one of: an indicator if a random access procedure is initiated for the satellite switch with a re-synchronization procedure; a cause of radio link failure (RLF) to indicate whether the RLF is due to a consecutive satellite switch with a re-synchronization procedure; or at least one parameter regarding the satellite switch with a re-synchronization procedure. The at least one parameter regarding the satellite switch with a re-synchronization procedure may comprise at least one of: an indication of a time since a last satellite switch with a re-synchronization execution until a loss of UL synchronization due to the satellite switch with a re-synchronization procedure; an indication of an absolute time when the UL synchronization is lost due to the satellite switch with a re-synchronization procedure; an indication of a validity duration for NTN related assistance information; a number of latest consecutive satellite switch with a re-synchronization procedure failure; an indication of an absolute time when the satellite switch with a re-synchronization procedure is obtained; an indication of a time since a first loss of UL synchronization due to the satellite switch with the re-synchronization procedure until the UL synchronization is obtained; or an indication of a physical cell identifier (PCI) of a source satellite; an indication of a PCI of a target satellite; an indication of a type of satellite switch that is a soft satellite switch; an indication of a type of satellite switch that is a hard satellite switch; an indication of whether the satellite switch is performed via a re-synchronization procedure; an indicator of whether the satellite switch is performed via a re-synchronization procedure without random access procedure; an indication of a time offset between a synchronization signal block (SSB) from a source satellite and a target satellite at a uplink time synchronization reference point; an indication of time information on when a target satellite is going to start serving an area currently covered by a serving satellite; or an indication of time information on when a cell provided via an NTN system is going to stop serving an area the cell is currently covering.
[0127] In some embodiments, the information may include satellite information of a first cell. The satellite information may comprise at least one of: an indication of an absolute time when a satellite is going to start serving the first cell; ephemeris information of a satellite when a satellite is going to start serving the first cell; or an indication of an epoch time of a satellite for NTN assistance information of the first cell. In some embodiments, the first cell may comprise at least one of: a serving cell that performs a logged measurement in a logged measurement report; at least one neighbor cell that performs the logged measurement in the logged measurement report; a cell at which the last measurement results was taken, where connection establishment failure or connection resume failure happened in a connection failure report; at least one neighbor cell at which the last measurement results was taken, where connection establishment failure or connection resume failure happened in the connection failure report; a primary cell (PCell) in which radio link failure (RLF) is detected or a target PCell of a failed handover in a radio link failure report; a candidate target cells for conditional handover at a time of connection failure in the radio link failure report; a candidate target cell for conditional handover that the wireless communication device selected for conditional handover (CHO) in the radio link failure report; a PCell in which radio link failure (RLF) is detected or a source PCell of a failed handover in an evolved universal terrestrial radio access (E-UTRA) radio link failure report; at least one neighbor E-UTRA cell that the last measurement results were taken, when radio link failure or handover failure happened in the radio link failure report; at least one neighbor new radio (NR) cell that the last measurement results were taken, when radio link failure or handover failure happened in the radio link failure report; a source PCell of a last handover in the radio link failure report; a PCell in which the wireless communication device failed to perform fast master cell group (MCG) recovery procedure or the wireless communication device successfully performed fast MCG recovery procedure in the radio link failure report; a cell in which the wireless communication device comes back to connected after connection failure and after failing to perform reestablishment in the radio link failure report; a cell in which a re-establishment attempt was made after connection failure in the radio link failure report; a target PCell of a handover for which a successful handover report was generated in a successful handover report; a target E-UTRA PCell of a handover in which the successful handover triggers the successful handover report; at least one neighboring NR cell that the last measurement results were taken when a successful handover is executed in the successful handover report; a source PCell of a handover in which the successful handover triggers the successful handover report; a target PCell of a handover in which the successful handover triggers the successful handover report; at least one neighbor cell that the last measurement was taken when a successful primary cell of a secondary cell group (SCG) (PSCell) change or addition is executed; a PCell to which the wireless communication device was connected when the successful PSCell change or addition in a successful PSCell report; a source PSCell of a PSCell change in which the successful PSCell change in the successful PSCell report; a target PSCell of a PSCell change in which the successful PSCell change in the successful PSCell report; or recently visited cell (s) in mobility history information.
[0128] In some embodiments, the information can be included in at least one of: a radio link failure report when a radio link failure is detected; a successful handover report when a successful handover is detected; a report that is stored when a satellite switch procedure is performed; a report of a logged measurement result; a report of a connection failure; or a report of mobility history information. In some embodiments, the information may include a duration of stay in an NTN cell.
[0129] In some embodiments, the wireless communication device may receive a request for the UL message from the wireless communication node. The wireless communication device may send the UL message according to the request to the wireless communication node.
[0130] In some embodiments, a wireless communication node (e.g., a gNB or a base station (BS) ) may receive an uplink (UL) message from a wireless communication device (e.g., a user equipment (UE) ) . The UL message may comprise information related to a non-terrestrial network (NTN) . In some embodiments, the wireless communication node (e.g., a gNB or a base station (BS) ) may send configuration information for optimizing network performance to the wireless communication device (e.g., a user equipment (UE) ) .
[0131] While various embodiments of the present solution have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. Likewise, the various diagrams may depict an example architectural or configuration, which are provided to enable persons of ordinary skill in the art to understand example features and functions of the present solution. Such persons would understand, however, that the solution is not restricted to the illustrated example architectures or configurations, but can be implemented using a variety of alternative architectures and configurations. Additionally, as would be understood by persons of ordinary skill in the art, one or more features of one embodiment can be combined with one or more features of another embodiment described herein. Thus, the breadth and scope of the present disclosure should not be limited by any of the above-described illustrative embodiments.
[0132] It is also understood that any reference to an element herein using a designation such as "first, " "second, " and so forth does not generally limit the quantity or order of those elements. Rather, these designations can be used herein as a convenient means of distinguishing between two or more elements or instances of an element. Thus, a reference to first and second elements does not mean that only two elements can be employed, or that the first element must precede the second element in some manner.
[0133] Additionally, a person having ordinary skill in the art would understand that information and signals can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits and symbols, for example, which may be referenced in the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.
[0134] A person of ordinary skill in the art would further appreciate that any of the various illustrative logical blocks, modules, processors, means, circuits, methods and functions described in connection with the aspects disclosed herein can be implemented by electronic hardware (e.g., a digital implementation, an analog implementation, or a combination of the two) , firmware, various forms of program or design code incorporating instructions (which can be referred to herein, for convenience, as "software" or a "software module) , or any combination of these techniques. To clearly illustrate this interchangeability of hardware, firmware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware or software, or a combination of these techniques, depends upon the particular application and design constraints imposed on the overall system. Skilled artisans can implement the described functionality in various ways for each particular application, but such implementation decisions do not cause a departure from the scope of the present disclosure.
[0135] Furthermore, a person of ordinary skill in the art would understand that various illustrative logical blocks, modules, devices, components and circuits described herein can be implemented within or performed by an integrated circuit (IC) that can include a general purpose processor, a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a field programmable gate array (FPGA) or other programmable logic device, or any combination thereof. The logical blocks, modules, and circuits can further include antennas and / or transceivers to communicate with various components within the network or within the device. A general purpose processor can be a microprocessor, but in the alternative, the processor can be any conventional processor, controller, or state machine. A processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other suitable configuration to perform the functions described herein.
[0136] If implemented in software, the functions can be stored as one or more instructions or code on a computer-readable medium. Thus, the steps of a method or algorithm disclosed herein can be implemented as software stored on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that can be enabled to transfer a computer program or code from one place to another. A storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer.
[0137] In this document, the term "module" as used herein, refers to software, firmware, hardware, and any combination of these elements for performing the associated functions described herein. Additionally, for purpose of discussion, the various modules are described as discrete modules; however, as would be apparent to one of ordinary skill in the art, two or more modules may be combined to form a single module that performs the associated functions according embodiments of the present solution.
[0138] Additionally, memory or other storage, as well as communication components, may be employed in embodiments of the present solution. It will be appreciated that, for clarity purposes, the above description has described embodiments of the present solution with reference to different functional units and processors. However, it will be apparent that any suitable distribution of functionality between different functional units, processing logic elements or domains may be used without detracting from the present solution. For example, functionality illustrated to be performed by separate processing logic elements, or controllers, may be performed by the same processing logic element, or controller. Hence, references to specific functional units are only references to a suitable means for providing the described functionality, rather than indicative of a strict logical or physical structure or organization.
[0139] Various modifications to the embodiments described in this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the scope of this disclosure. Thus, the disclosure is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the novel features and principles disclosed herein, as recited in the claims below.
Claims
1.A method comprising:sending, by a wireless communication device to a wireless communication node, an uplink (UL) message,wherein the UL message comprises information related to a non-terrestrial network (NTN) .2.The method of claim 1, comprising:receiving, by the wireless communication device from the wireless communication node, configuration information for optimizing network performance.3.The method of claim 1, wherein the information includes an indication that a cell related to at least one of the wireless communication device or the wireless communication node, is part of the NTN.4.The method of claim 3, wherein the information comprises at least one of: frequency information of the cell, or an indication of whether the cell is part of the NTN.5.The method of claim 3, wherein the cell comprises at least one of:a serving cell that performs a logged measurement in a logged measurement report;at least one neighbor cell that performs the logged measurement in the logged measurement report;a cell at which the last measurement results was taken, where connection establishment failure or connection resume failure happened in a connection failure report;at least one neighbor cell at which the last measurement results was taken, where connection establishment failure or connection resume failure happened in a connection failure report;a primary cell (PCell) in which radio link failure (RLF) is detected or a target PCell of a failed handover in a radio link failure report;at least one candidate target cell for conditional handover at a time of connection failure in a radio link failure report;a candidate target cell for conditional handover that the wireless communication device selected for conditional handover (CHO) in a radio link failure report;a PCell in which radio link failure (RLF) is detected or a source PCell of a failed handover in an evolved universal terrestrial radio access (E-UTRA) radio link failure report;at least one neighbor E-UTRA cell that the last measurement results were taken, when radio link failure or handover failure happened in a radio link failure report;at least one neighbor new radio (NR) cell that the last measurement results were taken, when radio link failure or handover failure happened in a radio link failure report;a source PCell of a last handover in a radio link failure report;a PCell in which the wireless communication device failed to perform fast master cell group (MCG) recovery procedure or the wireless communication device successfully performed fast MCG recovery procedure in a radio link failure report;a cell in which the wireless communication device comes back to connected after connection failure and after failing to perform reestablishment in a radio link failure report; a cell in which a re-establishment attempt was made after connection failure in a radio link failure report;a target PCell of a handover for which a successful handover report was generated in a successful handover report;a target E-UTRA PCell of a handover in which the successful handover triggers a successful handover report;at least one neighboring NR cell that the last measurement results were taken when a successful handover is executed in a successful handover report;a source PCell of a handover in which the successful handover triggers a successful handover report;a target PCell of a handover in which the successful handover triggers a successful handover report;at least one neighbor cell that the last measurement was taken when a successful primary cell of a secondary cell group (SCG) (PSCell) change or addition is executed;a PCell to which the wireless communication device was connected when a successful PSCell change or addition in a successful PSCell report;a source PSCell of a PSCell change in which a successful PSCell change in a successful PSCell report;a target PSCell of a PSCell change in which the successful PSCell change in a successful PSCell report; ora recently visited cell in mobility history information.6.The method of claim 1, wherein the information includes at least one NTN related measurement parameter.7.The method of claim 6, wherein the at least one NTN related measurement parameter comprises at least one of:an indication of a type of a NTN related measurement that is performed in RRC_IDLE state and / or RRC_INACTIVE state, wherein the NTN related measurement is a location-based measurement or a time-based measurement;an indication of a distance threshold that is used in location-based measurement initiation in RRC_IDLE state and / or RRC_INACTIVE state;an indication of a reference location of a serving cell at a time reference that is used in location-based measurement initiation in RRC_IDLE state and / or RRC_INACTIVE state;a list of terrestrial network (TN) coverage area information that is used to assist skipping TN measurements for NTN user equipment (UEs) in RRC_IDLE and / or RRC_INACTIVE state; ortime information regarding when a cell provided by an NTN system ceases serving the area the cell is currently covering.8.The method of claim 1, wherein the information includes at least one NTN related parameter.9.The method of claim 8, wherein the at least one NTN related parameter comprises at least one of:an indication of whether a last executed handover was an intra-NTN handover;an indication of whether a connection failure is due to a failure in an intra-NTN handover or an intra-NTN radio link;time information regarding when a cell provided by an NTN system ceases serving an area the cell is currently covering; ora list of NTN neighbor cells.10.The method of claim 1, wherein the information includes time-based conditional handover (CHO) information or location-based CHO information.11.The method of claim 10, wherein the time-based information comprises at least one of:an indication of an absolute time when a radio link failure (RLF) or handover failure is caused by time-based CHO;an indication of the absolute time when a successful handover is detected by time-based CHO;an indication of a time threshold that is used for time-based CHO;an indication of a duration that is used for defining a leaving condition for time-based CHO;an indication of a last executed handover before a last detected connection failure is a time-based CHO;an indication of a last executed handover before a last detected connection failure is a time-based CHO that is performed via random access channel (RACH) -less;an indication of whether a connected failure is due to a time-based CHO; oran indication of whether a connected failure is due to a time-based CHO that is performed via RACH-less.12.The method of claim 10, wherein the location-based CHO information comprises at least one of:an indication of a location of the wireless communication device when a radio link failure (RLF) or handover failure is caused by location-based CHO;an indication of coarse location of the wireless communication device when a radio link failure (RLF) or handover failure is caused by location-based CHO;an indication of a location of the wireless communication device when a successful handover is detected by location-based CHO;an indication of coarse location of the wireless communication device when a successful handover is detected by location-based CHO;an indication of one or more reference locations that are used for location-based CHO;an indication of one or more distance thresholds that are used for location-based CHO;an indication of a distance between the wireless communication device and the one or more reference locations when the RLF, the handover failure, or the successful handover is detected by location-based CHO;an indication of a last executed handover before a last detected connection failure is a location-based CHO; oran indication of whether a connected failure is due to a location-based CHO.13.The method of claim 2, wherein the configuration information includes a logged measurement configuration for at least one NTN cell.14.The method of claim 13, wherein the logged measurement configuration comprises at least one of:a list of tracking area codes for a tracking area identity in area configuration for logged measurement;an area configuration for an NTN system, wherein the area configuration includes a reference location and a distance threshold; orat least one coordinate point to mark area configuration for logged measurement.15.The method of claim 1, wherein the information includes random access channel (RACH) -less handover information.16.The method of claim 15, wherein the RACH-less handover information comprises at least one of:an indication of a last executed handover being a RACH-less handover;an indication of whether a connected failure is due to a RACH-less handover failure; orat least one RACH-less handover related parameter.17.The method of claim 16, wherein the at least one RACH-less handover related parameter comprises at least one of:an indication of reference signal received power (RSRP) for synchronization signal block (SSB) selection for a pre-allocated uplink grant;an initial value of a configured grant retransmission timer used for an initial uplink transmission of the RACH-less handover;a set of demodulation reference signal (DMRS) ports for SSB to physical uplink shared channel (PUSCH) mapping for the RACH-less handover;a number of DMRS sequences for SSB to PUSCH mapping for the RACH-less handover;a threshold of the RSRP configured for SSB selection for the pre-allocated uplink grant for the RACH-less handover;a number of SSBs per pre-allocated uplink grant PUSCH for the RACH-less handover; ora SSB subset for SSB to configured grant (CG) PUSCH mapping within a CG configuration for the RACH-less handover.18.The method of claim 1, wherein the information includes information regarding a satellite switch procedure.19.The method of claim 18, wherein the information regarding the satellite switch procedure comprises at least one of:an indicator if a random access procedure is initiated for the satellite switch with a re-synchronization procedure;a cause of radio link failure (RLF) to indicate whether the RLF is due to a consecutive satellite switch with a re-synchronization procedure; orat least one parameter regarding the satellite switch with a re-synchronization procedure.20.The method of claim 19, wherein the at least one parameter regarding the satellite switch with a re-synchronization procedure comprises at least one of:an indication of a time since a last satellite switch with a re-synchronization execution until a loss of UL synchronization due to the satellite switch with a re-synchronization procedure;an indication of an absolute time when the UL synchronization is lost due to the satellite switch with a re-synchronization procedure;an indication of a validity duration for NTN related assistance information;a number of latest consecutive satellite switch with a re-synchronization procedure failure;an indication of an absolute time when the satellite switch with a re-synchronization procedure is obtained;an indication of a time since a first loss of UL synchronization due to the satellite switch with the re-synchronization procedure until the UL synchronization is obtained;an indication of a physical cell identifier (PCI) of a source satellite;an indication of a PCI of a target satellite;an indication of a type of satellite switch that is a soft satellite switch;an indication of a type of satellite switch that is a hard satellite switch;an indication of whether the satellite switch is performed via a re-synchronization procedure;an indicator of whether the satellite switch is performed via a re-synchronization procedure without random access procedure;an indication of a time offset between a synchronization signal block (SSB) from a source satellite and a target satellite at a uplink time synchronization reference point;an indication of time information on when a target satellite is going to start serving an area currently covered by a serving satellite; oran indication of time information on when a cell provided via an NTN system is going to stop serving an area the cell is currently covering.21.The method of claim 1, the information includes satellite information of a first cell.22.The method of claim 21, wherein the satellite information comprises at least one of:an indication of an absolute time when a satellite is going to start serving the first cell;ephemeris information of a satellite when a satellite is going to start serving the first cell; oran indication of an epoch time of a satellite for NTN assistance information of the first cell.23.The method of claim 21, wherein the first cell comprises at least one of:a serving cell that performs a logged measurement in a logged measurement report; at least one neighbor cell that performs the logged measurement in the logged measurement report;a cell at which the last measurement results was taken, where connection establishment failure or connection resume failure happened in a connection failure report;at least one neighbor cell at which the last measurement results was taken, where connection establishment failure or connection resume failure happened in the connection failure report;a primary cell (PCell) in which radio link failure (RLF) is detected or a target PCell of a failed handover in a radio link failure report;a candidate target cells for conditional handover at a time of connection failure in the radio link failure report;a candidate target cell for conditional handover that the wireless communication device selected for conditional handover (CHO) in the radio link failure report;a PCell in which radio link failure (RLF) is detected or a source PCell of a failed handover in an evolved universal terrestrial radio access (E-UTRA) radio link failure report;at least one neighbor E-UTRA cell that the last measurement results were taken, when radio link failure or handover failure happened in the radio link failure report;at least one neighbor new radio (NR) cell that the last measurement results were taken, when radio link failure or handover failure happened in the radio link failure report;a source PCell of a last handover in the radio link failure report;a PCell in which the wireless communication device failed to perform fast master cell group (MCG) recovery procedure or the wireless communication device successfully performed fast MCG recovery procedure in the radio link failure report;a cell in which the wireless communication device comes back to connected after connection failure and after failing to perform reestablishment in the radio link failure report; a cell in which a re-establishment attempt was made after connection failure in the radio link failure report;a target PCell of a handover for which a successful handover report was generated in a successful handover report;a target E-UTRA PCell of a handover in which the successful handover triggers the successful handover report;at least one neighboring NR cell that the last measurement results were taken when a successful handover is executed in the successful handover report;a source PCell of a handover in which the successful handover triggers the successful handover report;a target PCell of a handover in which the successful handover triggers the successful handover report;at least one neighbor cell that the last measurement was taken when a successful primary cell of a secondary cell group (SCG) (PSCell) change or addition is executed;a PCell to which the wireless communication device was connected when the successful PSCell change or addition in a successful PSCell report;a source PSCell of a PSCell change in which the successful PSCell change in the successful PSCell report;a target PSCell of a PSCell change in which the successful PSCell change in the successful PSCell report; ora recently visited cell in mobility history information.24.The method of claim 1, wherein the information is included in at least one of:a radio link failure report when a radio link failure is detected;a successful handover report when a successful handover is detected;a new report that is stored when a satellite switch procedure is performed;a report of a logged measurement result;a report of a connection failure; ora report of mobility history information.25.The method of claim 1, wherein the information includes a duration of stay in an NTN cell.26.The method of claim 1, comprising:receiving, by the wireless communication device from the wireless communication node, a request for the UL message; andsending, by the wireless communication device to the wireless communication node, the UL message according to the request.27.A method comprising:receiving, by a wireless communication node from a wireless communication device, an uplink (UL) message,wherein the UL message comprises information related to a non-terrestrial network (NTN) .28.A non-transitory computer readable medium storing instructions, which when executed by at least one processor, cause the at least one processor to perform the method of any one of claims 1-27.29.An apparatus comprising:at least one processor configured to perform the method of any one of claims 1-27.
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