Management of ephemeris, time, delay, and ta for ntn

Abstract

A method for operating a user equipment (UE), the method comprising: receiving system information, the system information comprising: information corresponding to location coordinates of a non-terrestrial network (NTN) gateway, information corresponding to a processing delay between the UE and a base station (BS), and information corresponding to a reference point location; determining a timing advance based on a timing difference between the reference point location and the BS; transmitting a timing advance report based on the determined timing advance.

Description

Technical Field

[0001] This disclosure generally relates to wireless communication systems, and more specifically, to the management of ephemeris, time, delay, and TA for NTN. Background Technology

[0002] To meet the increased demand for wireless data services since the deployment of fourth-generation (4G) communication systems, efforts have been focused on developing improved fifth-generation (5G) or near-5G communication systems. 5G or near-5G communication systems are also referred to as "super-4G networks" or "post-Long Term Evolution (LTE) systems." 5G communication systems are considered to be implemented in higher frequency (mmWave) bands, such as the 60GHz band, to achieve higher data rates. To reduce radio wave propagation loss and increase transmission distance, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive MIMO technologies have been discussed for 5G communication systems. Furthermore, improvements to the system network are being developed based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, motion networks, cooperative communication, coordinated multipoint (CoMP), and receiver interference cancellation. In 5G systems, hybrid frequency shift keying (FSK) and Fair quadrature amplitude modulation (FQAM) and sliding window superposition coding (SWSC) have been developed as advanced coding and modulation (ACM), as well as filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) as advanced access technologies.

[0003] The Internet, a human-centric network of connections where humans generate and consume information, is now evolving into the Internet of Things (IoT), in which distributed entities, such as things, exchange and process information without human intervention. The Internet of Everything (IoE) has emerged, combining IoT technology with big data processing through connections to cloud servers. Because IoT implementation requires technological elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology, sensor networks, machine-to-machine (M2M) communication, and machine-type communication (MTC) have recently been researched. This IoT environment can provide intelligent Internet technology services, creating new value for human life by collecting and analyzing data generated between connected things. Through the convergence and combination of existing information technology (IT) and various industrial applications, IT can be applied to a wide range of fields, including smart homes, smart buildings, smart cities, smart or connected cars, smart grids, healthcare, smart devices, and advanced medical services.

[0004] Correspondingly, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, MTC, and M2M communication can be implemented through beamforming, MIMO, and array antennas. The application of cloud RAN, as a big data processing technology, can also be seen as an example of the integration between 5G and 10T technologies.

[0005] As mentioned above, various services can be provided based on the development of wireless communication systems, and therefore a method that makes it easy to provide such services is needed. Summary of the Invention

[0006] [Technical Solution]

[0007] This disclosure relates to wireless communication systems, and more specifically, to user equipment (UE). The UE includes a transceiver and a processor operatively connected to the transceiver. The transceiver is configured to receive system information, including information corresponding to location coordinates of a non-terrestrial network (NTN) gateway, information corresponding to a processing delay between the UE and a base station (BS), and information corresponding to a reference point location. The processor is configured to determine a timing advance based on a timing difference between the reference point location and the BS. The transceiver is also configured to transmit a timing advance report based on the determined timing advance. Attached Figure Description

[0008] To more fully understand this disclosure and its advantages, reference is now made to the following description in conjunction with the accompanying drawings, wherein like reference numerals denote like parts:

[0009] Figure 1 An exemplary wireless network according to an embodiment of this disclosure is shown;

[0010] Figure 2 An exemplary gNB according to an embodiment of this disclosure is shown;

[0011] Figure 3 An exemplary UE according to an embodiment of this disclosure is shown;

[0012] Figure 4 An exemplary wireless transmission path according to an embodiment of this disclosure is shown;

[0013] Figure 5 An exemplary wireless reception path according to an embodiment of this disclosure is shown;

[0014] Figure 6 An example of distance estimation according to an embodiment of this disclosure is shown;

[0015] Figure 7 An example of a management mechanism for ephemeris, time, and delay according to an embodiment of this disclosure is shown;

[0016] Figure 8 An example of operation for ephemeris, time and delay management according to an embodiment of this disclosure is shown;

[0017] Figure 9 An example of a general UE network process for ephemeris, time, and delay management according to an embodiment of this disclosure is shown;

[0018] Figure 10 A flowchart illustrating an exemplary gNB process supporting ephemeris and TA management according to an embodiment of this disclosure is shown;

[0019] Figure 11 A flowchart illustrating an exemplary UE process supporting ephemeris and TA management according to an embodiment of this disclosure is shown;

[0020] Figure 12 A proposed architecture for supporting time, ephemeris, and other aspects management of NTN is shown according to an embodiment of this disclosure;

[0021] Figure 13 A proposed architecture for supporting time, ephemeris, and other aspects management of NTN is shown according to an embodiment of this disclosure;

[0022] Figure 14 An example of the mechanism of a flexible cell reselection framework according to an embodiment of the present disclosure is shown;

[0023] Figure 15 An example of implementing flexible QoS operation according to an embodiment of this disclosure is shown;

[0024] Figure 16 An exemplary overall UE network procedure for a flexible cell reselection framework in an NTN according to an embodiment of this disclosure is shown;

[0025] Figure 17 An exemplary overall UE network procedure for a flexible cell reselection framework in an NTN according to an embodiment of this disclosure is shown;

[0026] Figure 18 An exemplary UE procedure for a flexible cell reselection framework in an NTN according to an embodiment of this disclosure is shown;

[0027] Figure 19 An exemplary network process for a flexible cell reselection framework in an NTN according to an embodiment of this disclosure is shown;

[0028] Figure 20 A flowchart of a method for operating a UE according to an embodiment of the present disclosure is shown;

[0029] Figure 21A flowchart of another method that can be performed by a BS according to an embodiment of this disclosure is shown;

[0030] Figure 22 A base station (BS) according to an embodiment of the present disclosure is shown; and

[0031] Figure 23 A user equipment (UE) according to an embodiment of this disclosure is shown. Detailed Implementation

[0032] This disclosure relates to wireless communication systems, and more specifically, to the management of ephemeris, time, delay, and timing advance (TA) of an NTN. Furthermore, while some elements of this disclosure are useful for both terrestrial networks (TN) and non-terrestrial networks (NTN), certain elements significantly enhance the performance of the NTN.

[0033] According to embodiments of this disclosure, a user equipment (UE) is provided. The UE includes a transceiver configured to receive system information, including: information corresponding to the location coordinates of a non-terrestrial network (NTN) gateway, information corresponding to a processing delay between the UE and a base station (BS), and information corresponding to a reference point location. The UE also includes a processor operatively connected to the transceiver. The processor is configured to determine a timing advance based on a timing difference between the reference point location and the BS. The transceiver is further configured to transmit a timing advance report based on the determined timing advance.

[0034] In one implementation, the transceiver is configured to: autonomously send a timing advance report when a condition is met or when random access is performed; periodically send a timing advance report; or send a timing advance report in response to a command from the BS.

[0035] In one implementation, the transceiver is configured to send a timing advance report via a Radio Resource Control (RRC) message or via a Media Access Control (MAC) control element (CE).

[0036] In one implementation, the system information includes long-term ephemeris data, wherein changes to the long-term ephemeris data are transmitted via flags.

[0037] In one implementation, the transceiver is configured to receive position and velocity data included in system information at a first cycle and a second cycle, respectively.

[0038] In one implementation, when the system information includes the parameter disable-s-IntraSearchP, the processor is configured to search for neighboring cells.

[0039] In one implementation, the system information includes neighbor cell selection information. Based on the neighbor cell selection information, the processor is configured to prioritize incoming cells over outgoing cells.

[0040] In one implementation, the system information further includes elliptical cell information, which includes the center, minor axis or minor semi-axis, and major axis or major semi-axis of the serving cell's interior area. The processor is also configured to determine whether the UE is within the serving cell's interior area based on the elliptical cell information and the UE's location. When the UE is outside the serving cell's interior area and signal measurements from neighboring cells meet a threshold, the processor is configured to send a measurement report or select a neighboring cell as the serving cell.

[0041] According to another embodiment of this application, a base station (BS) is provided. The BS includes a processor configured to: generate system information, including: information corresponding to the location coordinates of a non-terrestrial network (NTN) gateway, information corresponding to a processing delay between a UE and the base station BS, and information corresponding to a reference point location. The BS also includes a transceiver operatively connected to a transceiver. The transceiver is configured to: transmit the system information; and receive a timing advance report based on timing advance, wherein the timing advance is based on the timing difference between the reference point location and the base station.

[0042] In one implementation, the transceiver is configured to: autonomously receive timing advance reports when conditions are met or when random access is performed; periodically receive timing advance reports; or receive timing advance reports in response to commands from the BS.

[0043] In one implementation, the transceiver is configured to receive timing advance reports via Radio Resource Control (RRC) messages or via Media Access Control (MAC) control elements (CE).

[0044] In one implementation, the system information includes long-term ephemeris data, wherein changes to the long-term ephemeris data are transmitted via flags.

[0045] In one implementation, the transceiver is configured to transmit position and velocity data included in system information at a first cycle and a second cycle, respectively.

[0046] In one implementation, the parameter disable-s-IntraSearchP, included in the system information, is used to search for neighboring cells.

[0047] In one implementation, the system information includes neighboring cell selection information that indicates that entering a cell takes precedence over leaving a cell.

[0048] In one implementation, the system information further includes elliptical cell information, which includes the center, minor axis or minor semi-axis, and major axis or major semi-axis of the serving cell's interior area. When an indication is received that the user equipment (UE) is outside the serving cell's interior area and when the signal measurement of a neighboring cell meets a threshold, a measurement report is received or a neighboring cell is selected as the serving cell.

[0049] According to another embodiment of this disclosure, a method for operating a UE is provided. The method includes: receiving system information, which includes: information corresponding to the location coordinates of a non-terrestrial network (NTN) gateway, information corresponding to a processing delay between the UE and a base station (BS), and information corresponding to a reference point location; determining a timing advance based on the timing difference between the reference point location and the BS; and sending a timing advance report based on the determined timing advance.

[0050] In one implementation, the method further includes: autonomously sending a timing advance report when a condition is met or when random access is performed; periodically sending a timing advance report; or sending a timing advance report in response to a command from the BS.

[0051] In one implementation, the method further includes sending a timing advance report via a Radio Resource Control (RRC) message or via a Media Access Control (MAC) control unit (CE).

[0052] In one implementation, the system information includes long-term ephemeris data, wherein changes to the long-term ephemeris data are transmitted via flags.

[0053] Other technical features will be obvious to those skilled in the art based on the following figures, description and claims.

[0054] Before proceeding with the following detailed description, it may be advantageous to define certain words and phrases used throughout this patent document. The term “connection” and its derivatives refer to any direct or indirect communication between two or more elements, whether or not these elements are physically in contact with each other. The terms “transmit,” “receive,” and “communicate,” and their derivatives include both direct and indirect communication. The terms “include” and “comprise,” and their derivatives, mean non-restrictive inclusion. The term “or” is inclusive, meaning and / or. The phrase “associated with,” and its derivatives, mean including, being included within, interconnected with, including, being included in, connected to or connected with, linked to or connected with, capable of communicating with, cooperating with, intertwined, juxtaposed, proximate, bound to or bound with, having, possessing the characteristics of, having a relationship to or with, etc. The term “controller” refers to any device, system, or part thereof that controls at least one operation. Such a controller may be implemented in hardware, or a combination of hardware and software and / or firmware. The functionality associated with any particular controller can be centralized or distributed, local or remote. When the phrase "at least one" is used with a list of items, it means that different combinations of one or more of the listed items can be used, and only one item in the list may be required. For example, "at least one of A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C.

[0055] Furthermore, the various functions described below can be implemented or supported by one or more computer programs, each computer program being formed by computer-readable program code and included in a computer-readable medium. The terms "application program" and "program" refer to one or more computer programs, software components, instruction sets, procedures, functions, objects, classes, examples, associated data, or portions thereof suitable for implementation in appropriate computer-readable program code. The phrase "computer-readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer-readable medium" includes any type of medium accessible by a computer, such as read-only memory (ROM), random access memory (RAM), hard disk drive, optical disc (CD), digital video disc (DVD), or any other type of storage. "Non-transitory" computer-readable medium excludes wired, wireless, optical, or other communication links that transmit transient electrical or other signals. Non-transitory computer-readable medium includes media that can permanently store data, as well as media that can store data and subsequently rewrite it, such as rewritable optical discs or erasable storage devices.

[0056] Definitions of certain other words and phrases are provided in this patent document in general. Those skilled in the art will understand that, in many (if not most) examples, such definitions apply to the prior and future use of the words and phrases thus defined.

[0057] Fifth-generation (5G) or new radio (NR) mobile communications has recently gained momentum with a global surge of technical activity from industry and academia regarding various candidate technologies. The driving forces behind 5G / NR mobile communications include a wide range of antenna technologies, from traditional cellular bands to higher frequencies, to provide beamforming gain and support increased capacity; new waveforms that flexibly adapt to various services / applications with different needs (e.g., new radio access technologies (RAT)); and new multiple access schemes that support a large number of connections.

[0058] The following discussion Figures 1 to 21 The various embodiments used to describe the principles of this disclosure in this patent document are merely illustrative and should not be construed as limiting the scope of this disclosure in any way. Those skilled in the art will understand that the principles of this application can be implemented in any suitably arranged system or apparatus.

[0059] The following documents are incorporated herein by reference, as if fully set forth herein: 3GPP, TR 38.811v15.2.0, “Study on NR to support non-terminal networks”; 3GPP, TR 38.821v16.0.0, “Solutions for NR to support non-terrestrial networks (NTN)”; 3GPP, TS38.212v15.8.0, “5G; NR; Multiplexing and channel coding”; 3GPP, TS 38.211v15.8.0, “5G; NR; Physical channels and modulation”; 3GPP TS 38.321 v16.2.0, “NR; Medium Access Control (MAC) protocol specification”; and 3GPP TS 38.331v16.2.0, “NR; Radio Resource Control (RRC) Protocol Specification”.

[0060] The following Figures 1-3 Various implementations of orthogonal frequency division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) communication technologies are described in wireless communication systems. Figures 1-3 The description does not imply any limitation on the physical or architectural aspects of the different implementation methods that can be achieved. Different implementations of this disclosure can be implemented in any suitably arranged communication system.

[0061] Figure 1 An exemplary wireless network according to an embodiment of this disclosure is shown. Figure 1 The embodiments of the wireless network 100 shown are for illustrative purposes only. Other embodiments of the wireless network 100 may be used without departing from the scope of this disclosure.

[0062] like Figure 1 As shown, the wireless network 100 includes gNB 101 (e.g., a base station BS), gNB 102, and gNB 103. gNB 101 communicates with gNB 102 and gNB 103. gNB 101 also communicates with at least one network 130, such as the Internet, a proprietary Internet Protocol (IP) network, or other data network.

[0063] gNB 102 provides wireless broadband access to network 130 to multiple first user equipments (UEs) within its coverage area 120. The multiple first UEs include: UE 111, which may be located in a small business; UE 112, which may be located in an enterprise (E); UE 113, which may be located in a WiFi hotspot (HS); UE 114, which may be located in a first residence (R); UE 115, which may be located in a second residence (R); and UE 116, which may be a sports device (M), such as a cellular phone, wireless laptop computer, wireless PDA, etc. gNB 103 provides wireless broadband access to network 130 to multiple second UEs within its coverage area 125. The multiple second UEs include UE 115 and UE 116. In some implementations, one or more of gNBs 101-103 may communicate with each other and with UEs 111-116 using 5G / NR, LTE, LTE-A, WiMAX, WiFi or other wireless communication technologies.

[0064] Depending on the network type, the term "base station" or "BS" can refer to any component (or set of components) configured to provide wireless access to a network, such as a transmitting point (TP), a transmitting-receiving point (TRP), an enhanced base station (eNodeB or eNB), a 5G base station (gNB), a macro cell, a femtocell, a WiFi access point (AP), or other wireless-enabled equipment. A base station can provide wireless access according to one or more wireless communication protocols, such as 5G 3GPP New Radio Interface / Access (NR), Long Term Evolution (LTE), LTE Advanced (LTE-A), High Speed ​​Packet Access (HSPA), Wi-Fi 802.11a / b / g / n / ac, etc. For convenience, the terms "BS" and "TRP" are used interchangeably in this patent document to refer to network infrastructure components that provide wireless access to remote terminals. Furthermore, depending on the network type, the term "user equipment" or "UE" can refer to any component such as a "mobile station," "subscriber station," "remote terminal," "wireless terminal," "receiving point," or "user equipment." For convenience, the terms “user equipment” and “UE” are used in this patent document to refer to a remote wireless device that wirelessly accesses a BS, whether the UE is a mobile device (e.g., a mobile phone or smartphone) or is generally considered to be a fixed device (e.g., a desktop computer or a vending machine).

[0065] The dashed lines indicate the approximate extent of coverage areas 120 and 125, which are shown as approximately circular for illustrative and explanatory purposes only. It should be clearly understood that coverage areas associated with the gNB, such as coverage areas 120 and 125, may have other shapes, including irregular shapes, depending on the configuration of the gNB and variations in the radio environment associated with natural and man-made obstacles.

[0066] As described in more detail below, one or more of UEs 111-116 include circuitry, programming, or a combination thereof for receiving system information, which includes: information corresponding to the location coordinates of a non-terrestrial network (NTN) gateway; information corresponding to the processing delay between the UE and the base station (BS); information corresponding to a reference point location; determining timing advance based on the timing difference between the reference point location and the BS; and sending a timing advance report based on the determined timing advance. One or more of gNBs 101-103 include circuitry, programming, or a combination thereof for generating system information, which includes: information corresponding to the location coordinates of a non-terrestrial network (NTN) gateway; information corresponding to the processing delay between the user equipment (UE) and the base station; information corresponding to a reference point location; sending system information; and receiving a timing advance report based on the timing advance, wherein the timing advance is based on the timing difference between the reference point location and the base station.

[0067] As discussed in more detail below, the wireless network 100 may have communications facilitated via one or more communication satellites 104, which may be in orbit above the Earth. The communication satellites 104 may communicate directly with BSs 102 and 103 to provide network access, for example, when BSs 102 and 103 are located remotely, or when network access needs to be facilitated in addition to conventional forward and / or backhaul connections. Various UEs (e.g., as shown in UE 116) are capable of at least some direct communication and / or positioning with the communication satellites 104, such as receiving location information or coordinates.

[0068] although Figure 1 An example of a wireless network is shown, but more can be found on... Figure 1 Various modifications can be made. For example, the wireless network can include any number of gNBs and any number of UEs. Furthermore, gNB 101 can communicate directly with any number of UEs and provide those UEs with wireless broadband access to network 130. Similarly, each gNB 102-103 can communicate directly with network 130 and provide UEs with direct wireless broadband access to network 130. Additionally, gNBs 101, 102, and / or 103 can provide access to other or additional external networks, such as external telephone networks or other types of data networks.

[0069] Figure 2 An exemplary gNB 102 according to an embodiment of this disclosure is shown. Figure 2 The embodiment of gNB 102 shown is for illustrative purposes only. Figure 1 gNBs 101 and 103 can have the same or similar configurations. However, gNBs have multiple configurations, and Figure 2 This disclosure is not intended to limit the scope to any particular implementation of gNB.

[0070] like Figure 2 As shown, gNB 102 includes multiple antennas 205a-205n, multiple radio frequency (RF) transceivers 210a-210n, transmit (TX) processing circuitry 215, and receive (RX) processing circuitry 220. gNB 102 also includes a controller / processor 225, a memory 230, and a backhaul or network interface 235.

[0071] RF transceivers 210a-210n receive input RF signals from antennas 205a-205n, such as signals transmitted by a UE in network 100. RF transceivers 210a-210n down-convert the input RF signals to generate IF or baseband signals. The IF or baseband signals are sent to RX processing circuitry 220, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. RX processing circuitry 220 sends the processed baseband signals to controller / processor 225 for further processing.

[0072] TX processing circuit 215 receives analog or digital data (e.g., voice data, web data, email, or interactive video game data) from controller / processor 225. TX processing circuit 215 encodes, multiplexes, and / or digitizes the output baseband data to generate a processed baseband or IF signal. RF transceivers 210a-210n receive the processed baseband or IF signal from TX processing circuit 215 and up-convert the baseband or IF signal into an RF signal transmitted via antennas 205a-205n.

[0073] The controller / processor 225 may include one or more processors or other processing devices that control the overall operation of the gNB 102. For example, the controller / processor 225 may control the reception of forward channel signals and the transmission of reverse channel signals via RF transceivers 210a-210n, RX processing circuitry 220, and TX processing circuitry 215, according to known principles. The controller / processor 225 may also support additional functions, such as more advanced wireless communication functions. For example, the controller / processor 225 may support beamforming or directional routing operations, wherein the output / input signals from / to multiple antennas 205a-205n are weighted differently to effectively manipulate the output signals in the desired direction. The controller / processor 225 may support any of a variety of other functions in the gNB 102.

[0074] The controller / processor 225 can also execute programs and other processes residing in the memory 230, such as an operating system. The controller / processor 225 can move data into or out of the memory 230 as needed during execution.

[0075] The controller / processor 225 is also coupled to a backhaul or network interface 235. The backhaul or network interface 235 allows the gNB 102 to communicate with other devices or systems via a backhaul connection or over a network. Interface 235 can support communication via any suitable wired or wireless connection. For example, when the gNB 102 is implemented as part of a cellular communication system (e.g., a system supporting 5G / NR, LTE, or LTE-A), interface 235 can allow the gNB 102 to communicate with other gNBs via a wired or wireless backhaul connection. When the gNB 102 is implemented as an access point, interface 235 can allow the gNB 102 to communicate with a larger network (e.g., the Internet) via a wired or wireless local area network or via a wired or wireless connection. Interface 235 includes any suitable architecture supporting communication over a wired or wireless connection, such as an Ethernet or RF transceiver.

[0076] The memory 230 is coupled to the controller / processor 225. A portion of the memory 230 may include RAM, while another portion of the memory 230 may include flash memory or other ROM.

[0077] although Figure 2 An example of gNB 102 is shown, but it is possible to compare it with other models. Figure 2 Various changes can be made. For example, gNB 102 can include any number of Figure 2 Each component shown. As a particular example, an access point may include multiple interfaces 235. As another particular example, although shown as a single example including TX processing circuitry 215 and a single example including RX processing circuitry 220, gNB 102 may include multiple examples of each (e.g., one example per RF transceiver). Furthermore, Figure 2 The various components can be combined, subdivided, or omitted, and additional components can be added as needed.

[0078] Figure 3 An exemplary UE 116 according to an embodiment of this disclosure is shown. Figure 3 The implementation of UE 116 shown is for illustrative purposes only. Figure 1 UEs 111-115 can have the same or similar configurations. However, UEs have multiple configurations, and Figure 3 This disclosure is not intended to limit the scope to any particular implementation of the UE.

[0079] like Figure 3As shown, UE 116 includes an antenna 305, a radio frequency (RF) transceiver 310, a TX processing circuit 315, a microphone 320, and a receive (RX) processing circuit 325. UE 116 also includes a speaker 330, a processor 340, an input / output (I / O) interface (IF) 345, a touchscreen 350, a display 355, and a memory 360. The memory 360 includes an operating system (OS) 361 and one or more applications 362.

[0080] RF transceiver 310 receives an input RF signal transmitted by a gNB of network 100 from antenna 305. RF transceiver 310 down-converts the input RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is sent to RX processing circuitry 325, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. RX processing circuitry 325 transmits the processed baseband signal to speaker 330 (e.g., for voice data) or processor 340 for further processing (e.g., for web browsing data).

[0081] The TX processing circuit 315 receives analog or digital voice data from the microphone 320 or other output baseband data (such as web data, email, or interactive video game data) from the processor 340. The TX processing circuit 315 encodes, multiplexes, and / or digitizes the output baseband data to generate a processed baseband or IF signal. The RF transceiver 310 receives the processed baseband or IF signal from the TX processing circuit 315 and up-converts the baseband or IF signal into an RF signal transmitted via the antenna 305.

[0082] Processor 340 may include one or more processors or other processing devices and executes OS 361 stored in memory 360 to control the overall operation of UE 116. For example, processor 340 may control the reception of forward channel signals and the transmission of reverse channel signals through RF transceiver 310, RX processing circuitry 325, and TX processing circuitry 315 according to known principles. In some embodiments, processor 340 includes at least one microprocessor or microcontroller.

[0083] Processor 340 is also capable of executing other processes and programs residing in memory 360, such as a process for receiving system information, including: information corresponding to the location coordinates of the non-terrestrial network (NTN) gateway; information corresponding to the processing delay between the UE and the base station (BS); information corresponding to the reference point location; determining timing advance based on the timing difference between the reference point location and the BS; and sending a timing advance report based on the determined timing advance. Processor 340 may move data into or out of memory 360 as needed during execution. In some embodiments, processor 340 is configured to execute application 362 based on OS 361 or in response to signals received from gNB or operator. Processor 340 is also coupled to I / O interface 345, which provides UE 116 with the ability to connect to other devices such as laptop computers and handheld computers. I / O interface 345 is the communication path between these accessories and processor 340.

[0084] The processor 340 is also connected to the touchscreen 350 and the display 355. The operator of the UE 116 can use the touchscreen 350 to input data into the UE 116. The display 355 may be a liquid crystal display, a light-emitting diode display, or other display capable of displaying text and / or at least limited graphics, such as from a website.

[0085] The memory 360 is coupled to the processor 340. A portion of the memory 360 may include random access memory (RAM), and another portion of the memory 360 may include flash memory or other read-only memory (ROM).

[0086] although Figure 3 An example of UE 116 is shown, but it is possible to modify it. Figure 3 Make various changes. For example, Figure 3 The various components can be combined, subdivided, or omitted, and additional components can be added as needed. As a specific example, processor 340 can be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). Furthermore, although... Figure 3 The UE 116 is shown configured as a mobile phone or smartphone, but the UE can be configured to operate as other types of mobile or fixed devices.

[0087] To meet the increased demand for wireless data services since the deployment of 4G communication systems, and to enable various vertical applications, 5G / NR communication systems have been developed and are currently being deployed. 5G / NR communication systems are considered to be implemented in higher frequency (mmWave) bands (e.g., 28 GHz or 60 GHz bands) to achieve higher data rates, or in lower frequency bands (e.g., 6 GHz) to achieve robust coverage and motion support. To reduce radio wave propagation loss and increase transmission distance, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive MIMO technologies are discussed in 5G / NR communication systems.

[0088] In addition, in 5G / NR communication systems, system network improvements are being developed based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, motion networks, cooperative communication, coordinated multipoint (CoMP), and receiver interference cancellation.

[0089] The discussion of 5G systems and their associated frequency bands is for reference only, as some embodiments of this disclosure can be implemented in 5G systems. However, this application is not limited to 5G systems or their associated frequency bands, and embodiments of this application can be used in conjunction with any frequency band. For example, aspects of this disclosure can also be applied to the deployment of 5G communication systems, 6G, or even newer versions using terahertz (THz) frequency bands.

[0090] The communication system includes downlink (DL) and uplink (UL). Downlink (DL) refers to the transmission from the base station or one or more transmission points to the UE, and uplink (UL) refers to the transmission from the UE to the base station or to one or more receiving points.

[0091] The time unit used for DL ​​or UL signaling on a cell is called a time slot, and it can include one or more symbols. Symbols can also be used as additional time units. Frequency (or bandwidth (BW)) units are called resource blocks (RBs). An RB includes multiple subcarriers (SCs). For example, a time slot can have a duration of 0.5 milliseconds or 1 millisecond and include 14 symbols, and an RB can include 12 SCs with inter-SC spacing of 15 kHz or 30 kHz, and so on.

[0092] DL signals include data signals that transmit information content, control signals that transmit DL control information (DCI), and reference signals (RS), also known as pilot signals. The gNB transmits data information or DCI via the corresponding Physical DL Shared Channel (PDSCH) or Physical DL Control Channel (PDCCH). PDSCH or PDCCH can be transmitted on a variable number of time slot symbols, each consisting of one time slot symbol. For simplicity, the DCI format received by the UE via scheduled PDSCH is referred to as the DL DCI format, and the DCI format transmitted via the Physical Uplink Shared Channel (PUSCH) from the UE is referred to as the UL DCI format.

[0093] The gNB transmits one or more of several types of RS, including Channel State Information RS (CSI-RS) and Demodulation RS (DMRS). CSI-RS is primarily used by the UE to perform measurements and provide CSI to the gNB. For channel measurements, the Non-Zero Power CSI-RS (NZP CSI-RS) resource is used. For Interference Measurement Reporting (IMR), the CSI Interference Measurement (CSI-IM) resource associated with the Zero Power CSI-RS (ZP CSI-RS) configuration is used. The CSI process includes both NZP CSI-RS and CSI-IM resources.

[0094] The UE can determine the CSI-RS transmission parameters via DL control signaling or higher-layer signaling (such as Radio Resource Control (RRC) signaling) from the gNB. The transmission example of CSI-RS can be indicated by DL control signaling or configured by higher-layer signaling. DM-RS is transmitted only in the BW of the corresponding PDCCH or PDSCH, and the UE can use DMRS to demodulate data or control information.

[0095] Figure 4 and Figure 5 Exemplary wireless transmit and receive paths according to this disclosure are illustrated. In the following description, transmit path 400 may be described as being implemented in a gNB (e.g., gNB 102), while receive path 500 may be described as being implemented in a UE (e.g., UE 116). However, it will be understood that receive path 500 may be implemented in a gNB, and transmit path 400 may be implemented in a UE. In some embodiments, receive path 500 is configured to support codebook designs and structures of systems with 2D antenna arrays as described in embodiments of this disclosure.

[0096] like Figure 4The transmission path 400 shown includes a channel coding and modulation block 405, a serial-to-parallel (S-to-P) block 410, an N-size inverse fast Fourier transform (IFFT) block 415, a parallel-to-serial (P-to-S) block 420, a cyclic prefix addition block 425, and an up-converter (UC) 430. For example... Figure 5 The receiver path 500 shown includes a downconverter (DC) 555, a cyclic prefix removal block 560, a serial-to-parallel (S-to-P) block 565, a fast Fourier transform (FFT) block of size N, a parallel-to-serial (P-to-S) block 575, and a channel decoding and demodulation block 580.

[0097] like Figure 4 As shown, the channel coding and modulation block 405 receives a set of information bits, applies coding (e.g., low-density parity-check (LDPC) coding), and modulates the input bits (e.g., using quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM)) to produce a frequency domain modulated symbol sequence.

[0098] Serial-to-parallel block 410 converts (e.g., demultiplexes) serial modulated symbols into parallel data to generate N parallel symbol streams, where N is the IFFT / FFT size used in gNB 102 and UE 116. IFFT block 415 of size N performs an IFFT operation on the N parallel symbol streams to generate a time-domain output signal. Parallel-to-serial block 420 converts (e.g., multiplexes) the parallel time-domain output symbols from IFFT block 415 of size N to generate a serial time-domain signal. Cyclic prefix addition block 425 inserts a cyclic prefix into the time-domain signal. Upconverter 430 modulates (e.g., upconverts) the output of cyclic prefix addition block 425 to an RF frequency for transmission over a wireless channel. The signal can also be filtered at baseband before conversion to the RF frequency.

[0099] The transmitted RF signal from gNB 102 reaches UE 116 after passing through the wireless channel, and performs the opposite operation at UE 116 as at gNB 102.

[0100] like Figure 5 As shown, downconverter 555 downconverts the received signal to the baseband frequency, and cyclic prefix removal block 560 removes the cyclic prefix to generate a serial time-domain baseband signal. Serial-to-parallel block 565 converts the time-domain baseband signal into a parallel time-domain signal. FFT block 570 of size N performs the FFT algorithm to generate N parallel frequency-domain signals. Parallel-to-serial block 575 converts the parallel frequency-domain signals into a sequence of modulated data symbols. Channel decoding and demodulation block 580 demodulates and decodes the modulated symbols to recover the original input data stream.

[0101] Each of gNBs 101-103 can perform actions similar to those sent to UEs 111-116 in the downlink. Figure 4 The transmission path 400 shown can achieve a similar effect to that received from UE 111-116 in the uplink. Figure 5 The receive path 500 is shown. Similarly, each of UEs 111-116 can implement a transmit path 400 for sending to gNBs 101-103 in the uplink and a receive path 500 for receiving from gNBs 101-103 in the downlink.

[0102] Figure 4 and Figure 5 Each component can be implemented using only hardware or a combination of hardware and software / firmware. As a specific example, Figure 4 and Figure 5 At least some components can be implemented in software, while others can be implemented in configurable hardware, or a combination of software and configurable hardware. For example, FFT block 570 and IFFT block 415 can be implemented as configurable software algorithms, where the value of size N can be modified according to the implementation method.

[0103] Furthermore, although described as using FFT and IFFT, this is merely exemplary and should not be construed as limiting the scope of this disclosure. Other types of transforms, such as Discrete Fourier Transform (DFT) and Inverse Discrete Fourier Transform (IDFT) functions, can be used. It will be understood that for DFT and IDFT functions, the value of variable N can be any integer (e.g., 1, 2, 3, 4, etc.), while for FFT and IFFT functions, the value of variable N can be any integer that is a power of 2 (e.g., 1, 2, 4, 8, 16, etc.).

[0104] although Figure 4 and Figure 5 An example of a wireless transmit and receive path is shown, but it is possible to modify it further. Figure 4 and Figure 5 Make various changes. For example, Figure 4 and Figure 5 The various components can be combined, subdivided, or omitted, and additional components can be added as needed. Furthermore, Figure 4 and Figure 5 This example illustrates the types of send and receive paths that can be used in a wireless network. Any other suitable architecture can be used to support wireless communication in a wireless network.

[0105] Non-terrestrial networks (NTNs) refer to networks or network segments that utilize RF resources on communication satellites (or unmanned aerial vehicle (UAV) system platforms) (e.g., Communication Satellite 104). Given their ability to provide broad coverage and reliable service, NTNs are envisioned to universally ensure service availability and continuity. For example, NTNs can support communication services in unserved areas not covered by conventional terrestrial networks, in areas experiencing limited or unreliable communication, for equipment and passengers on mobile vehicle platforms, and for future rail / sea / air communication, etc.

[0106] In NTN, the cell may be in motion, leading to inaccurate platform location awareness at the UE and various types of propagation and processing delays in the system. Knowledge of the various delays and predictions in the platform ephemeris data can be used to make more accurate timing adjustment (TA) estimates, resulting in better pre-compensation at the UE.

[0107] Figure 6 An example 600 of distance estimation according to an embodiment of the present disclosure is shown. Figure 6 The implementation of Example 600 for distance estimation shown is for illustrative purposes only. Figure 6 This disclosure is not intended to limit the scope to any particular implementation of the distance estimation example 600.

[0108] like Figure 6 As shown, the UE is attempting to estimate its distance to the antenna / spacecraft platform (e.g., a satellite). This distance estimate can then be used for any timing pre-compensation at the UE. This knowledge can also be used to determine, report, and utilize appropriate timing advance.

[0109] The air interface / spacecraft platform acquires its own GNSS-based position at time t1. This information reaches the gNB via the NTN gateway. The gNB places the satellite (whose position may have changed) in the appropriate System Information (SI). The UE receives the satellite position at time tN and can now compare the satellite position at time tN with its own position. Although Figure 6 The image shows an air / spacecraft platform moving from left to right, but such a platform could also be stationary relative to a point on the Earth's surface.

[0110] Figure 7 Example 700 of a management mechanism for ephemeris, time and delay according to an embodiment of this disclosure is shown. Figure 7 The implementation of Example 700, which illustrates the management mechanism for ephemeris, time, and delay, is for illustrative purposes only. Figure 7 This disclosure is not intended to limit the scope of any particular implementation of the example 700 of the ephemeris, time, and delay management mechanism.

[0111] like Figure 7As shown, the gNB receives information such as ephemeris, time, NTN type, component delay, and component measurement, and sends information about transmission, signaling, and / or configuration of ephemeris, time, and delay.

[0112] Figure 8 Example 800 of operation for ephemeris, time and delay management according to an embodiment of this disclosure is shown. Figure 8 The implementation of the exemplary operation 800 for ephemeris, time and delay management shown is for illustrative purposes only. Figure 8 This disclosure is not intended to limit the scope to any particular implementation of the exemplary operation 800 for ephemeris, time, and delay management.

[0113] like Figure 8 As shown, the air interface / spacecraft platform obtains its position and time and provides relevant ephemeris information and time to the NTN GW and / or gNB. Entities such as the platform, NTN GW, OAM, and / or user interface provide delay details to the gNB. The gNB uses system information to transmit relevant delays, times, etc., to the UE. The gNB configures and / or instructs the UE to perform TA and time reporting via broadcast, multicast / multicast, RRC, MAC, and / or PHY signaling. The UE uses the information provided by the gNB to adjust its TA. The UE reports its time and TA to each configured gNB. The gNB adjusts the TA and sends appropriate MAC / PHY commands to the UE to make any adjustments. The gNB sends time / TA report requests via system information, multicast / multicast, RRC, MAC, or PHY signaling, and the UE provides such reports.

[0114] Table 1 specifies examples of various moments and delays associated with one or more embodiments of this disclosure.

[0115] [Table 1]

[0116]

[0117]

[0118]

[0119] Table 1 Examples of time and delay aspects in NTN

[0120] Figure 9 Example 900 of a general UE network process for ephemeris, time and delay management according to an embodiment of this disclosure is shown. Figure 9 The implementation of the exemplary overall UE network procedure 900 for ephemeris, time, and latency management shown is for illustrative purposes only. Figure 9This disclosure is not intended to limit the scope to any particular implementation of the exemplary general UE network procedure 900 for ephemeris, time, and latency management.

[0121] In operation F9S1, in the exemplary method, an airborne or spacecraft platform such as a satellite / HAPS (referred to as the “Platform” or box 811), an NTN gateway, and a gNB exchange one or more delays as shown in the exemplary Table 1.

[0122] In F9S2 operation, in an exemplary method, the platform transmits selected ephemeris data (e.g., position (x, y, z) and velocity (Vx, Vy, vz)) and time to the NTN gateway using real-time signaling. In another method, orbital parameters including time (“epochs”) are sent by the platform. In yet another implementation, reference point coordinates (e.g., corresponding to the cell center) are also specified by the platform. Alternatively, the NTN GW, OAM system, application server, or entity within the gNB, or an entity connected to the gNB, may provide reference point coordinates to the gNB based on the selected ephemeris data and known satellite beam parameters (e.g., beam coverage) and time. In yet another method, orbital parameters including time (“epochs”) are used to specify the platform's location.

[0123] In Operation F9S3, in the exemplary method, the NTN-GW uses the history of the selected ephemeris data and knowledge of propagation and processing delays to predict the time at which the UE will receive this information from the gNB via the NTN-GW and the platform at a reference point in the cell, and subsequently specifies the selected ephemeris data. In an alternative approach, the NTN-GW does not perform this prediction but instead forwards the received, originally selected ephemeris data and the time received from the platform to the gNB.

[0124] In operation F9S4, in the exemplary method, the gNB uses the history of the selected ephemeris data and knowledge about propagation and processing delays to predict the time at which the UE will receive this information from the gNB via the NTN GW and the platform at a reference point in the cell, and then specifies the selected ephemeris data. In an alternative approach, the gNB does not perform this prediction but instead uses the original or modified selected ephemeris data and time from the NTN GW.

[0125] In F9S5 operation, in an exemplary method, the gNB specifies one or more times, selected ephemeris data associated with the one or more times, and reference point location coordinates associated with the one or more times to the NTN GW for eventual transmission to the UE. In another embodiment of this disclosure, the gNB also specifies the location coordinates of one or more NTN-GWs (generally referred to as "coordinates" for simplicity in this disclosure). For example, typically one NTN-GW is sufficient for a given NTN cell until a feeder link handover is required. In an exemplary implementation, the time suitability of the NTN-GW for a given UE or set of UEs is also determined by the gNB and potentially transmitted to the UE by the gNB. In embodiments of this disclosure, the gNB constructs one or more SIBs to transmit one or more times, selected ephemeris data associated with the one or more times, reference point location coordinates associated with the one or more times, and / or NTN-GW location coordinates to the NTN GW, such that different information can be transmitted at different configurable periods. For example, longer-term or event-based information such as NTN-GW location coordinates is transmitted less frequently, while more real-time information such as short-term ephemeris data is transmitted more frequently. Furthermore, in the exemplary method, certain system information, such as NTN-GW coordinates, is transmitted using multicast / multicast signaling, wherein a subset of UEs in the cell (rather than all UEs in the cell) receives the selected NTN-GW information.

[0126] In operation F9S5, in embodiments of this disclosure, the gNB specifies to the UE via broadcast, multicast / multicast signaling and / or UE-specific RRC signaling which parameters to use directly and which parameters to estimate to facilitate pre-compensation, TA calculation and TA reporting.

[0127] Examples of times that the gNB can specify include the current time observed by the gNB, the time provided by the platform (i.e., the time when the platform's position is determined / obtained from the GNSS), and / or the time provided by the NTN-GW, as well as the expected reception time of the SIB at the reference point. In embodiments of this disclosure, time can be fully adequate (e.g., hours, minutes, seconds, etc.). In another embodiment of this disclosure, time can be expressed in a compact manner (e.g., by avoiding larger time scales such as hours and minutes).

[0128] In embodiments of this disclosure, during operation F9S1, as part of the configuration signaling exchange or via configuration of the OAM system, server, or user interface, the NTN-GW and gNB are configured with instructions on which entity (i.e., the platform, gNB, NTN-GW, or a new entity) will make such a prediction of the platform ephemeris at a future time, and with an identifier for such a future time such as one or more of the following: (i) the time when the gNB creates the SIB message, (ii) the time when the NTN-GW receives the SIB from the gNB, (iii) the time when the platform receives the SIB, (iv) the time when the reference point in the cell receives the SIB, and (v) the time when the UE receives the SIB.

[0129] In operation F9S6, in an exemplary method, the NTN-GW sends one or more times, selected ephemeris data associated with one or more times, reference point coordinates associated with one or more times, and a selected delay to the platform, and the platform sends this information to the UE on the access / service link.

[0130] In F9S7 operation, the UE obtains the received time, ephemeris data, reference point coordinates, and delay.

[0131] In operation F9S8, the UE determines an appropriate timing advance as part of pre-compensation for timing (and frequency) adjustments. In an exemplary embodiment of this disclosure, depending on a specific pre-compensation method, the UE uses (i) the reference point location and the gNB, and (ii) the timing difference between the UE's location and the gNB, to estimate the timing adjustments required for its uplink transmission. In the exemplary method, the UE assumes that the gNB-to-UE delay and the UE-to-gNB delay are symmetrical when the periodicity of information updates related to time, ephemeris numbers, reference point coordinates, and delay is sufficiently fast to meet accuracy requirements. In another method, the UE assumes that the gNB-to-UE delay and the UE-to-gNB delay are asymmetrical when calculating the timing advance. More specifically, the UE may utilize or predict time and ephemeris data at the moment when its transmission is expected to be received by the gNB.

[0132] In an exemplary implementation, the UE uses the following formula to estimate the reception time at the gNB.

[0133] t_gNB=t_ue+2*

[0134] t_gNB_to_ue_delay_observed+t_ue_to_platform_adjustment+t_platform_to_gNB_adjustment

[0135] In the above formula, t_ue_to_platform_adjustment and t_platform_to_gNB_adjustment reflect the timing adjustments caused by delay asymmetry due to the different locations of the platform (and potentially the UE) during transmissions from gNB to UE and from UE to gNB. In an exemplary implementation, the total TA applied by the UE is calculated as (2*t_gNB_to_ue_delay_observed+t_ue_to_platform_adjustment+t_platform_to_gNB_adjustment) in the formula.

[0136] In F9S9 operation, the UE uses pre-compensation (e.g., UE-autonomous, network-assisted, or network-indicated) to perform uplink transmissions. In an exemplary implementation, the gNB uses broadcast or multicast / multicast signaling to indicate the type of pre-compensation method supported or permitted in the cell. Furthermore, in the exemplary implementation, the parameters to be used by the UE and the conditions under which such parameters apply are implicitly defined (e.g., via specifications in the standard) or explicitly configured by the gNB.

[0137] In operation F9S10, in one exemplary method, the gNB configures the TA report to the UE via dedicated RRC signaling. In another exemplary method, the gNB may broadcast or multicast parameters or indicators to configure the UE using the relevant TA report. In one implementation, the gNB may configure the UE to report the complete TA (i.e., the TA covering both the gNB-to-UE delay and the UE-to-gNB delay). In another implementation, the gNB may configure the UE to report an incremental TA relative to a reference point. In yet another implementation, the TA may be specified relative to the minimum common delay based on the NTN type (e.g., a delay calculated based on the platform type such as GEO / LEO / HAPS and the minimum distance between the platform and the UE).

[0138] In F9S11 operation, the UE sends a TA report to the gNB. In one approach, the UE can send a TA report autonomously when certain conditions are met (e.g., when the absolute or relative TA exceeds a certain amount, or when random access is performed during handover or non-handover). In another approach, the UE sends a TA report periodically (e.g., every X milliseconds). In yet another approach, the gNB can command the UE to send a TA report, and the UE responds with a TA.

[0139] In F9S11 operation, TA reports are sent by gNB in ​​RRC messages (e.g., measurement reports and RRC recovery) or at each low layer of the configuration (e.g., UCI or MAC control elements).

[0140] For long-term ephemeris data (i.e., data valid for periods longer than minutes or hours), in F9S12 operation, the network uses various mechanisms (e.g., broadcast, multicast / multicast, or unicast signaling in the NTN, pre-provisioning to the UE in the SIM, or non-NTN signaling (e.g., using a traditional cellular network or Wi-Fi network). Changes to long-term ephemeris data can be communicated using a valueFlag associated with a specific version of the long-term ephemeris data. In the exemplary method, the UE only searches for new long-term ephemeris data when the valueFlag changes in the appropriate SIB. The updated data can be delivered incrementally (i.e., changing only specific parameters or completely replacing old data). In the exemplary method, the periodicity of the valueFlag, the periodicity of the long-term ephemeris data, and the periodicity of changing the long-term ephemeris data are controlled independently.

[0141] Several approaches are possible for the time specified in the steps above. In one approach, the time is absolute (e.g., UTC or GNSS-based time). In another approach, to reduce overhead, only the time with higher granularity (e.g., minutes and seconds or seconds) is specified, while skipping the time with lower granularity (e.g., hours or hours and minutes). In yet another approach, absolute time is sent periodically, while incremental or granular time is sent more frequently. In yet another approach, when multiple times are specified in a single message, one time can be selected as the reference time and can be specified as an absolute time with all granularities (e.g., hours, minutes, seconds, etc.) or with a selected granularity (e.g., seconds only), and other non-reference times can be incremental times relative to that reference time.

[0142] In an exemplary implementation, in addition to the timing for gNB-to-UE transmission, the timing for UE-to-gNB transmission can also be specified. For example, suitable entities (e.g., gNB, platform, and NTN-GW, where gNB is a conventional choice) can specify the time and location at which a UE signal is expected at the platform, NTN-GW, and / or gNB. This information enables the UE to accurately calculate the UE-to-platform delay and the platform-to-NTN-GW delay.

[0143] Several methods are possible for the platform position and speed specified in the steps above. First, the position and speed can be sent at the same or different periods. For example, the position can be sent in one period, but the speed in another. The values ​​of position and speed may change to different degrees from one moment to the next. Therefore, if the quantity does not change rapidly, it can be sent less frequently. Conversely, if the quantity changes rapidly, it needs to be sent more frequently so that the UE's understanding of the platform's position and speed is accurate. Furthermore, in one method, absolute values ​​are used. In another method, absolute values ​​are sent at some periodicity, and the changes in values ​​are sent more frequently. In yet another method, when multiple positions and multiple speeds are specified in a single message, a set of values ​​is selected as a reference, and other non-reference values ​​are specified as increments relative to that reference time. Additionally, if a newer position is specified but a newer speed is not, the previously specified speed is used.

[0144] Figure 10 A flowchart of an exemplary gNB process 1000 supporting ephemeris and TA management according to an embodiment of this disclosure is shown. Figure 10 The implementation of the exemplary gNB process 1000 for ephemeris and TA management shown is for illustrative purposes only. Figure 10 This disclosure is not intended to limit the scope to any particular implementation of the exemplary gNB process 1000 that supports ephemeris and TA management.

[0145] In Operation F10S1, the gNB transmits ephemeris data with a relatively long time correlation in the system information. This data can be included in an existing SIB from version 16, or in a new SIB from version 17 and above. This SIB is transmitted at a period known to the UE in the cell, and it can be fixed or configurable. In an exemplary implementation, the gNB specifies the NTN-GW coordinates so that the UE can estimate the UE-gNB round-trip delay (RTD) or round-trip time (RTT). Transmitting the NTN-GW coordinates relative to the feeder link delay is a better alternative due to its higher accuracy and more efficient signaling. Where appropriate, information about more than one NTN-GW is specified (e.g., to support anticipated changes in the NTN-GW). In another implementation, in Operation F10S1, the gNB specifies the total processing delay between the UE and the gNB, reflecting the processing delay in both directions from the UE to the gNB and from the gNB to the UE. The total processing latency includes one or more of the following: platform (e.g., satellite) processing time, NTN-GW processing time, gNB processing time, and gNB-NTN-GW transmission latency. In an exemplary method, the gNB may transmit its coordinates in the SIB.

[0146] Prior to operating F10S1, in embodiments of this disclosure, the gNB exchanges messages with its NTN-GW and platform to obtain regular platform and NTN-GW processing times. In another approach, the gNB may obtain these times from OAM or other systems. The gNB also obtains or estimates the gNB-NTN-GW transmission delay.

[0147] In Operation F10S2, the gNB transmits data with relatively short time correlation in its system information. This data may be included in an existing SIB from version 16, or in a new SIB from version 17 and above. This SIB is transmitted at a period known to the UEs in the cell, and it may be fixed or configurable. In an exemplary implementation, compared to the information presented in Operation F10S1, the gNB transmits ephemeris data or selected elements in Earth-Centered Earth-Fixed (ECEF) Cartesian position coordinates (Px, Py, and Pz coordinates) more frequently, and optionally transmits instantaneous velocities (Vx, Vy, and Vz) (derived from the ephemeris data).

[0148] In an exemplary embodiment of this disclosure, the absolute values ​​of position and velocity are represented in one SIB, and increment values ​​(i.e., values ​​relative to the absolute values) are specified in another SIB in a compact representation to reduce the number of openings.

[0149] In another example, different numbers of bytes are used to represent Px, Py, Pz, Vx, Vy, and Vz, instead of using the same number of bits for these parameters. In particular, parameters whose changes from one SIB example to the next are not expected to be significant can be represented by fewer bits.

[0150] In yet another example, the size (i.e., the number of bytes) of Px, Py, Pz, Vx, Vy, and Vz is determined by considering the sensitivity of the position and velocity estimation accuracy. In this case, more bits are used.

[0151] In embodiments of this disclosure, one or more of (Px, Py, Pz, Vx, Vy, and Vz) are encoded using a formula such as the following equation (1) to reduce the number of bits in the SIB:

[0152] Equation (1):

[0153] TV = α*IV + β

[0154] In equation (1), TV is the actual value of the quantity, and IV is the indicated value specified in the SIB.

[0155] The expected ranges of (Px, Py, Pz, Vx, Vy, and Vz) are used to determine α and β. In special cases, β can be 0 and therefore is not used. α and β are signaled in the SIB or predefined in the specification.

[0156] In the exemplary method, when signaling is sent in the SIB, α and β are transmitted at a lower frequency compared to IV. Furthermore, α and β can be different for all (Px, Py, Pz, Vx, Vy, and Vz), or the same α and β can be shared for multiple quantities.

[0157] In another exemplary approach, one or more tables are defined in the standard to represent the relationship between TV and IV for a given quantity. The IV can then be a simple index of the table entries.

[0158] Information in operations F10S1 and F10S2 is sent at a fixed or configurable period (in this case, the period is specified in the SIB). This period can be equal to, longer than, or shorter than the 160ms SIB1 period supported by R16.

[0159] Platform ephemeris data or position and velocity data specified by the gNB can correspond to the time at which the gNB creates the relevant SIB. In embodiments of this disclosure, such data can correspond to a future time, such as the time when the UE at the cell center will receive such an SIB. The UE can know this time through a procedure defined in the specification, or the gNB can provide an indication of using the future time in an appropriate SIB.

[0160] In an exemplary method, the gNB utilizes real-time platform ephemeris data or position and velocity data provided by the NTN-GW, along with historical data, to predict platform ephemeris data or position and velocity data at a target future time.

[0161] In embodiments of this disclosure, during operation F10S1 or F10S2, the gNB broadcasts the coordinates of a reference point in the cell so that the UE can estimate the delay from the reference point to the gNB. In another embodiment, the UE can use these coordinates to determine the relative TA for reporting. This information can be used by UEs without timing pre-compensation capabilities, UEs without GNSS, and UEs temporarily lacking GNSS visibility. In another embodiment of this disclosure, the gNB broadcasts the delay from the reference point to the gNB, which can be used by UEs without timing pre-compensation capabilities, UEs without GNSS, and UEs temporarily lacking GNSS visibility. This delay can also be used by the UE to report an incremental TA relative to the reference point TA.

[0162] In embodiments of this disclosure, during operation F10S1 or operation F10S2, the gNB includes a value flag indicating whether long-term NTN data (e.g., selected elements in the platform ephemeris) has been changed to avoid unnecessary SI processing at the UE.

[0163] In embodiments of this disclosure, if comprehensive long-term platform ephemeris data is provided to the UE in a file (e.g., on a SIM or via an air interface update), the current or latest version number of such file is broadcast by the gNB so that the UE can obtain updated ephemeris data (e.g., via application layer signaling).

[0164] In embodiments of this disclosure, if comprehensive long-term platform ephemeris data is provided to the UE in a file (e.g., on a SIM or via an air interface update), time and coordinates are represented in a compact manner to reduce file size. For example, the complete time and complete coordinates can be specified in a limited number of records in the file, and incremental time and coordinates can be specified in the remaining records in the file.

[0165] When operations F10S1 and F10S2 are related to the platform ephemeris, operations F10S3 through F10S9 are related to the management of timing advance (TA).

[0166] In operation F10S3, in an exemplary embodiment of this disclosure, the type of TA report that the gNB transmits to the UE via unicast signaling (e.g., RRC reconfiguration message), broadcast signaling (e.g., SIB processed by all UEs in the cell), or multicast / multicast signaling (e.g., a message processed by a subset of UEs in the cell) is configured for the UE.

[0167] In embodiments of this disclosure, TA reporting can be asynchronous or on-demand, wherein the gNB can send a PHY indication (e.g., DCI) or a MAC indication (e.g., MAC CE) to the UE to obtain TA reporting from the UE.

[0168] In another embodiment of this disclosure, the TA report may be periodic, wherein the gNB configures the periodicity of the TA report to the UE.

[0169] In another embodiment of this disclosure, the reporting of the TA can be implicit or rule-based, wherein the UE sends a TA when the TA changes (i.e., the difference between the previously reported TA and the currently estimated TA) exceeding a threshold. In this case, in an exemplary method, the gNB configures the threshold to the UE. In another exemplary method, the threshold is predefined in the specification.

[0170] In one embodiment of this disclosure, the TA is reported absolute (i.e., complete TA), and in another embodiment, incremental TA is reported.

[0171] In another embodiment of this disclosure, the (full or incremental) TA may be an index of a table entry or a formula such as equation (1), where TV is the (full or incremental) TA estimated by the UE, and IV is the TA value included in the TA report.

[0172] One or more TA reporting methods can be used simultaneously for a given UE. Furthermore, one or more TA reporting methods can be mandatory for the UE.

[0173] In operation F10S4, the gNB checks whether it wants to use asynchronous TA reporting. If so, operation F10S5 is executed. Otherwise, operation F10S6 is executed.

[0174] In F10S5 operation, the gNB determines whether it needs or wants to send a command to the UE to obtain an asynchronous or on-demand TA report. For example, if a long time has passed since the last TA report was received, or if the UE's UL appears to be out of sync or missing sync during each gNB determination process, the gNB can request the UE to send a TA report via PHY or MAC signaling.

[0175] In operation F10S6, the gNB checks whether periodic TA reports have been configured for the UE. If not, operation F10S8 is performed. If so, in operation F10S7, the gNB observes the periodic timer value, and if the timer is about to expire, the gNB waits for an incoming TA report from the UE.

[0176] In operation F10S8, the gNB checks whether a TA report has been received from the UE. If not, the gNB proceeds to operation F10S1. If yes, the gNB processes the received TA report from the UE in operation F10S9 and sends any TA adjustments if necessary. Furthermore, if a timer for periodic TA reporting has expired, it is restarted to prepare for a new TA report.

[0177] In an exemplary implementation, during operation F10S8, the gNB can receive an indication from the UE that the UE currently lacks GNSS visibility. In an exemplary method, this indication can be specified in the TA report itself. In this case, a single bit can indicate the lack of such GNSS visibility at the current moment. In another method, a TA report value itself (e.g., all 0s or all 1s or any other suitable bit pattern) can indicate the lack of GNSS visibility. The gNB can decide to accommodate a larger time difference between DL and UL (e.g., between (i) UL resource allocation and UL data transmission, and (ii) between DL transmission and ACK / NACK transmission in UL).

[0178] The TA report itself can be received by the gNB via PHY, MAC, or RRC signaling, or it can be received together with UL data in the appropriate header.

[0179] In another embodiment of this disclosure, during operation F10S8, the gNB receives indications of lack of GNSS visibility via PHY signaling (e.g., as UCI), MAC signaling (e.g., as part of MAC CE), or RRC signaling, or along with UL data in an appropriate header. In a particular embodiment, the gNB may then allow for a longer time margin between DL and UL processing.

[0180] Figure 11 A flowchart of an exemplary UE process 1100 supporting ephemeris and TA management according to an embodiment of this disclosure is shown. Figure 11 The implementation of the exemplary UE procedure 1100 that supports ephemeris and TA management shown is for illustrative purposes only. Figure 11 This disclosure is not intended to limit the scope to any particular implementation of the exemplary UE procedure 1100 that supports ephemeris and TA management.

[0181] In operation F11S1, the UE receives comprehensive long-term ephemeris data via SIM provisioning or NTN (e.g., in an SIB). In an exemplary embodiment of this disclosure, the UE receives this data from an application server or OAM system via a terrestrial network (TN) such as a cellular network or a WiFi network. In another embodiment of this disclosure, if comprehensive long-term platform ephemeris data is provided to the UE in a file (e.g., on a SIM or via an air interface update via a TN or NTN), the time and coordinates are represented in a compact manner to reduce the file size. For example, the complete time and complete coordinates can be specified in a limited number of records in the file, and incremental time and coordinates can be specified in the remaining records in the file.

[0182] In operation F11S2, UE processing includes one or more SIBs containing ephemeris data with relatively long time correlations. This data may be included in existing SIBs from version 16 or in new SIBs from version 17 and above. These SIBs are transmitted at periods known to the UE in the cell and may be fixed or configurable. In an exemplary implementation, the UE utilizes NTN-GW coordinates to estimate the UE-gNB RTD or RTT; see equation (E2) below. In another implementation, in operation F11S2, the UE receives the total processing delay between the UE and the gNB and utilizes this delay in equation (E2). The total processing delay includes one or more of the following: platform (e.g., satellite) processing time, NTN-GW processing time, gNB processing time, and gNB-NTN-GW transmission delay. The UE may also receive gNB coordinates from the SIB.

[0183] In Operation F11S3, the UE receives data with relatively short temporal correlation in the system information. This data may be included in an existing SIB from version 16, or in a new SIB from version 17 and above. This SIB is transmitted at a period known to the UE in the cell, and it may be fixed or configurable. In an exemplary implementation, the UE receives ephemeris data or selected elements in Earth-centered fixed (ECEF) Cartesian position coordinates (Px, Py, and Pz) more frequently than the information presented in Operation F11S2, and optionally receives instantaneous velocities (Vx, Vy, and Vz) (already derived from the ephemeris data). Where applicable, the UE uses a formula defined in a specification such as Equation (1) to obtain one or more of (Px, Py, Pz, Vx, Vy, and Vz). In another exemplary approach, the UE uses one or more tables defined in a standard to represent the relationship between TV and IV for a given quantity in Equation (1).

[0184] In an exemplary embodiment of this disclosure, the UE performs a predictive estimate of the platform's current position and / or velocity by considering the difference between the time associated with such information and the time when the UE uses such information. For example, the UE may perform linear or nonlinear extrapolation to more accurately estimate the platform's position and velocity at the time when such information is needed.

[0185] In embodiments of this disclosure, if the gNB has broadcast the coordinates of a reference point in the cell during operation F11S1 or F11S3, the UE can use the reference point coordinates to estimate the delay from the reference point to the gNB when needed. In another embodiment, the UE uses the reference point coordinates to determine the relative TA for TA reporting. This information can be used by UEs without timing pre-compensation capabilities, UEs without GNSS, and UEs temporarily lacking GNSS visibility. In another embodiment of this disclosure, if the gNB has broadcast the delay from the reference point to the gNB, UEs without timing pre-compensation capabilities, UEs without GNSS, and UEs temporarily lacking GNSS visibility can use this delay for timing pre-compensation. This delay can also be used by the UE to report an incrementing TA relative to the reference point TA.

[0186] If, during operation F11S2 or F11S3, the gNB has already included a value flag indicating whether long-term NTN data (e.g., selected elements of the platform ephemeris) has changed, the UE uses this flag to determine whether to obtain the long-term NTN data. For example, if the value flag stored in the UE matches the value flag sent by the gNB, the UE already has the latest long-term data, and the UE skips processing of the SI that includes the long-term NTN data. Conversely, if these value flags do not match, the UE performs further processing of the system information to obtain new long-term NTN data.

[0187] In embodiments of this disclosure, if comprehensive long-term platform ephemeris data is provided to the UE in a file (e.g., on a SIM or via an air interface update), and if the current or latest version number of such file is broadcast by a gNB, then if the version number associated with its currently stored data does not match the version number being broadcast by the gNB, the UE obtains updated ephemeris data (e.g., via application layer signaling).

[0188] exist Figure 11 In this context, operations F11S1, F11S2, and F11S3 are related to the platform's ephemeris, while operations F11S4 through F11S10 are related to the management of the TA.

[0189] In operation F11S4, in an exemplary embodiment of this disclosure, the UE obtains the type of TA report configuration from the gNB via unicast signaling (e.g., RRC reconfiguration message), broadcast signaling (e.g., SIB processed by all UEs in the cell), or multicast / multicast signaling (e.g., a message processed by a subset of UEs in the cell).

[0190] In embodiments of this disclosure, where TA reporting is configured to be asynchronous or on-demand, the UE expects to receive a PHY indication (e.g., DCI) or a MAC indication (e.g., MAC CE) from the gNB for TA reporting.

[0191] In another embodiment of this disclosure, if the UE is configured for periodic reporting of TA, the UE receives periodic TA reports.

[0192] In another embodiment of this disclosure, the reporting of the TA can be implicit or rule-based, wherein the UE is expected to send a TA when the TA changes (i.e., the difference between the previously reported TA and the currently estimated TA) exceeding a threshold. In this case, in the exemplary method, the UE receives the threshold from the gNB.

[0193] In one embodiment of this disclosure, if the UE stores a TA report of type: (i) an absolute or complete TA report, or (ii) an incremental TA report.

[0194] In another embodiment of this disclosure, the (full or incremental) TA may be an index of a table entry or a formula such as equation (1), where TV is the (full or incremental) TA estimated by the UE, and IV is the TA value included in the TA report.

[0195] One or more TA reporting methods can be used simultaneously for a given UE. Furthermore, one or more TA reporting methods can be mandatory for the UE.

[0196] In operation F11S5, the UE checks whether the asynchronous TA report has been configured by the gNB. If so, operation F11S6 is executed. Otherwise, operation F11S7 is executed.

[0197] In operation F11S6, the UE checks whether the gNB has sent a command to perform an asynchronous TA report or an on-demand TA report. If the UE has received such a command from the gNB, it sends a TA report to the gNB and proceeds with operation F11S7.

[0198] In operation F11S7, the UE checks whether the periodic TA report has been configured by the gNB. If not, operation F11S9 is performed. If so, in operation F11S8, the UE observes the periodic timer value, and if the timer expires, the UE sends a TA report to the gNB, resets the periodic timer, and performs operation F11S9.

[0199] In an exemplary embodiment of this disclosure, during operation F11S9, the UE with GNSS capability checks whether GNSS is available. If it is not available, the UE performs operation F11S10. Otherwise, the UE performs operation F11S11.

[0200] In operation F11S10, the UE sends a "GNSS unavailable" indication to the gNB and proceeds to operation F11S11.

[0201] In operation F11S11, the UE checks whether the gNB has sent a TA command. If not, the UE performs operation F11S1. If the gNB has sent a TA command, the UE assumes that the TA command adjusts its UL timing and performs operation F11S1.

[0202] exist Figure 11 In this process, the UE sends a TA report to the gNB via PHY, MAC, or RRC signaling, or sends a TA report along with UL data in the appropriate header.

[0203] Figure 12 A proposed architecture 1200 for supporting time, ephemeris, and other aspects management of NTN according to an embodiment of this disclosure is shown. Figure 12 The implementation of the proposed architecture 1200 for supporting time, ephemeris, and other aspects of NTN management shown is for illustrative purposes only. Figure 12 This disclosure is not intended to limit the scope to any particular implementation of the proposed architecture 1200 that supports time, ephemeris, and other aspects of NTN management.

[0204] Figure 12 The structure shown is suitable for transparent payloads and integrated gNBs. The integrated gNB combines the functions of gNB-DU (gNB distributed unit) and gNB-CU (gNB central unit).

[0205] One or more network functions and an access network (e.g., TN using cellular access or WiFi access or NTN) can be used to provide short-term and long-term NTN data to the UE.

[0206] exist Figure 12In this context, the Network Platform (NP) is the NTN entity that carries space-based (e.g., satellite) or air-based (e.g., HAPS) bearers. The Network Infrastructure (NI) consists of the NTN platform and the NTN Gateway. The NTN Infrastructure Controller (NIC) is a controller for specific implementations of the NTN infrastructure (e.g., satellite / HAPS and NTN-GW). The NIC acts as an agent for the NI and connects to traditional 5G Network Functions (NFs). The NIC exchanges long-term and latency-insensitive information with the appropriate 5G NF. For example, the NIC provides the IP address and (latitude and longitude) location of the NTN-GW to the gNB or gNB-NTN. The NIC obtains information about the platform through the NTN-GW. The Application Server (AS) provides long-term NTN data, such as long-term satellite ephemeris, to the NTN UE via a wired or wireless connection. This data may, for example, be appropriately stored in the Universal Subscriber Identity Module (USIM) or the UE's memory. The gNB-NTN is an optional logical function within the gNB that connects to the NI for NI-related signaling. For example, gNB-NTN exchanges real-time or near-real-time NTN data with NTN-GW, such as satellite (position, velocity, and time) vectors. Additionally, gNB-NTN exchanges long-term data with NTN-GW or NIC, such as information about selected orbital parameters and NTN-GW capabilities or processing. NTN-GW capabilities include the ability to modify (P, V, T) parameters provided by the platform.

[0207] The NTN-GW has two connections with the gNB or gNB-NTN: (i) a control plane connection for exchanging signaling messages such as gNB and NTN-GW processing capabilities (e.g., modifications to raw (P, V, T) data) and (P, V, T) parameters, and (ii) NR-Uu waveforms to be transmitted in the cell or received from all NTN UEs in the cell.

[0208] The eNTN-GW implements the traditional NTN-GW functions and supports NR baseband signals instead of NR RF signals. To enhance reliability, a wired interface based on high-speed fiber optics can be used instead of a wireless interface, employing protocols such as eCPRI between the gNB and the eNTN-GW.

[0209] The transmission of CP signaling and NR-specific signals (e.g., RF or baseband signals) between NTN-GW (or eNTN-GW) and gNB (or gNB-NTN) may initially be implementation-specific (i.e., beyond the 3GPP scope) and may be opened up in the future based on industry interests.

[0210] The feeder link also has two connections between the platform and the gNB or gNB-NTN: (i) a control plane connection for exchanging signaling messages including (P, V, T) parameters; and (ii) NR-Uu waveforms to be transmitted in the cell or received from all UEs in the cell.

[0211] Typically, the following connections can be wired (e.g., fiber optic in an IP network or metropolitan area Ethernet network) or wireless (e.g., using a microwave dish antenna): (i) Nnic-NTN-gw, (ii) NgNB-nic, (iii) NgNB-ntn-gw, (iv) Nnic-mgmt.

[0212] gNB-DU can be in the same position as NTN-GW / eNTN-GW, or in a different position from NTN-GW / eNTN-GW.

[0213] Figure 13 A proposed architecture 1300 for supporting time, ephemeris, and other aspects management of NTN according to an embodiment of this disclosure is shown. Figure 13 The implementation of the proposed architecture 1300 for supporting time, ephemeris, and other aspects of NTN management shown is for illustrative purposes only. Figure 13 This disclosure is not intended to limit the scope to any particular implementation of the proposed architecture 1300 that supports the management of time, ephemeris, and other aspects of NTN.

[0214] Figure 13 The architecture shown applies to transparent payloads and depolymerized or decomposed gNBs. The depolymerized gNB has two separate entities, gNB-DU and gNB-CU.

[0215] In an exemplary embodiment of this disclosure, information regarding the transmit power and receive power (e.g., receive sensitivity) of the NTN platform is transmitted to the gNB by an entity. This entity may be the NTN platform, NTN-GW, NTN controller, OAM, or application server. In this exemplary method, the power transmitted by the platform can be used by the gNB to inform it what is being broadcast in the SIB.

[0216] In embodiments of this disclosure, when a gNB broadcasts ephemeris data to the serving cell and neighboring cells, it only includes different satellite ephemeris data, rather than copying the same satellite ephemeris for multiple cells to reduce signaling overhead. For example, if multiple cells belong to the same satellite, the ephemeris data for that satellite is not repeated for all of them.

[0217] In embodiments of this disclosure, the UE utilizes time delay-related information broadcast by the gNB to facilitate its operation in the following situations: (i) the UE has GNSS capability but currently does not have accurate or reliable GNSS-based location (e.g., due to poor GNSS visibility), (ii) the UE has GNSS capability but does not have pre-compensation capability, and (iii) the UE does not have GNSS capability.

[0218] In embodiments of this disclosure, for the cases specified above, the UE utilizes delay information broadcast by the gNB to determine timer settings at each protocol layer, such as drx-HARQ-RTT-TimerUL, drx-HARQ-RTT-TimerDL, ra-ResponseWindow, ra-ContentionResolutionTimer, and sr-ProhibitTimer. When the UE has reliable / accurate knowledge of its specific UE-to-gNB delay, the UE can add an offset before these timers start, or existing timer values ​​(e.g., depending on the definition in version 16) can be incremented by the UE-to-gNB delay amount; both methods are equivalent. In exemplary embodiments of this disclosure, UEs without reliable GNSS-based self-localization estimate their UE-to-gNB delay by using delay information broadcast by the gNB for the three cases described above. Details of the "delay information" are given below.

[0219] In one approach, the delay information includes the gNB-to-reference point delay estimated by the gNB, where the reference point delay may correspond to the delay between the gNB and the average location (e.g., the cell center). In another approach, the reference point corresponds to the location within the cell with the minimum propagation delay. The one-way delay or round-trip delay is specified by the gNB.

[0220] In the exemplary method, the delay includes only the propagation delay. In another method, the delay is a total delay that includes one or more of the following: processing delay (e.g., NTN platform processing and NTN-GW processing) and transmission delay (e.g., NTN-GW-gNB transmission delay). In an exemplary embodiment of this disclosure, the gNB may indicate the type of delay it is broadcasting.

[0221] In another approach, the delay is divided into several parts, such as serving link delay, feeder link delay, and (optionally) other miscellaneous delays (e.g., processing and transmission delays). In this case, a UE without an accurate / reliable GNSS-based location can estimate the serving link delay using either an explicit serving link delay (if broadcast by the gNB) or the coordinates of a reference point (e.g., the cell center or a point associated with minimum delay). The feeder link delay can be explicitly broadcast, or the gNB can broadcast NTN-GW coordinates.

[0222] In an exemplary embodiment of this disclosure, the gNB may broadcast its own coordinates so that the UE can estimate the feeder link delay.

[0223] In an exemplary embodiment of this disclosure, if the UE's GNSS-based location is unavailable but the time at the UE is still accurate, the UE can estimate the UE-to-gNB delay by subtracting the SI transmission time broadcast by the gNB from the reception time of the relevant SI.

[0224] In an exemplary embodiment of this disclosure, when a UE reports its location to the network, it indicates, quantitatively or qualitatively, the confidence level of that location accuracy. For example, the UE may indicate that GNSS is currently not visible. The UE may indicate that the location corresponds to a recently known GNSS-based location.

[0225] In an exemplary embodiment of this disclosure, when the UE has accurate / reliable GNSS-based location available, the UE calculates the total delay between the UE and the gNB as follows.

[0226] Equation (E1):

[0227] UE-gNB Total Delay = "UE-specific UE-platform propagation delay" + "Common platform-NTN-GW propagation delay" + "Total Processing Delay"

[0228] In equation (E1), the UE estimates the UE-specific UE-platform propagation delay based on the platform coordinates broadcast in SI by the gNB and its own GNSS-based location. In an exemplary method, the distance between the UE and platform I is divided by the speed of light (e.g., 3 × 10⁸ m / s) to determine the propagation delay between the UE and the platform.

[0229] In the exemplary approach, in equation (E1), the “public platform-NTN-GW propagation delay” (also known as the “feeder link delay”) can be broadcast in the SI by the gNB. In another approach, the NTN-GW coordinates (or even the gNB coordinates as a proxy) and platform coordinates are used to determine the propagation delay between the platform and the NTN-GW, rather than the time-varying feeder link delay.

[0230] In equation (E1), the "total processing delay" is the sum of the following terms:

[0231] (i) Add two or more of the following: minimum or regular processing latency at the platform, NTN-GW, and gNB.

[0232] (ii) NTN-GW-gNB transmission delay, which can be specified as a minimum performance specification, part of the default assumptions, or broadcast by the gNB in ​​the SI.

[0233] The round-trip time (RTT) between the UE and gNB can be estimated by the UE (under the symmetry assumption) as follows:

[0234] Equation (E2):

[0235] UE-gNB RTT = 2 * UE-gNB Total Delay

[0236] In another embodiment of this disclosure, if the UE does not have pre-compensation capability, or if GNSS is currently unavailable (or a threshold time (X ms) has elapsed since the precise GNSS-based location became available), or if the UE does not have GNSS capability, the UE can use the following equation (E3) to estimate the total UE-gNB delay.

[0237] Equation (E3):

[0238] UE-gNB Total Delay = "Common Reference Point-platform propagation delay" + "Common platform-NTN-GW propagation delay" + "Total Processing Delay"

[0239] In equation (E3), the “common reference point-platform propagation delay” is the propagation delay between the common reference point (e.g., the center of the serving cell or another suitable point in a geographic area being illuminated by the cell beam) and the platform.

[0240] In the exemplary method, the “total processing latency” can be set to 0 in equation (E3).

[0241] Additional implementation methods for TA reports

[0242] In embodiments of this disclosure, during operation F9S6, the UE transmits a Reporting Acquisition (TA) in the MAC CE during the random access procedure based on such reporting being enabled or disabled by the gNB in ​​the SIB. For example, the gNB specifies the indicator taReportingEnabled in the SIB (e.g., SIB1, non-SIB2, or a new NTN SIB). If this indicator is 1 (or "0"), the UE reports a TA in the MAC CE during the RA procedure. In another exemplary method, TaReporting is not explicitly included in the SIB, and its presence or absence implies that the UE should or should not send a TA report to the gNB during the RA procedure.

[0243] In another embodiment of this disclosure, when the UE receives a TA report configuration via RRC signaling, this configuration (including enabled or disabled TA reports) replaces the TA report indicator that the UE has already received from the SIB.

[0244] In another embodiment of this disclosure, if the UE has moved to a new cell in any RRC state (e.g., due to cell reselection or handover), the UE uses a TA report configuration that includes enabling / disabling a TA report feedback indicator if such an indicator is implicitly received (e.g., whether an IE is present or not) or explicitly received. If no such indicator for the new cell is received via dedicated RRC signaling, the UE uses an indicator obtained via SIB.

[0245] In embodiments of this disclosure, the TA report configuration is specified by the gNB in ​​an SIB (e.g., an SIB for NTN or an enhanced SIB for a new NTN SIB) during operation F9S6 to store radio resources associated with specifying the TA report configuration to a number of UEs via dedicated signaling during operation F9S10.

[0246] In embodiments of this disclosure, the UE considers the priority of the MAC CE including the TA report to determine whether to send the MAC CE during the RA procedure (e.g., in msgA or msg3 / msg5) or later. In an exemplary method, if the UE cannot send the MAC CE in msgA, msg3, or msg4, the UE sends the MAC CE at a first opportune moment, where sufficient uplink resources are available for sending the MAC CE including the TA report at the first opportune moment.

[0247] In another embodiment of this disclosure, a MAC CE including a TA report is given a higher priority than a MAC CE including a power headroom report. In another method, a MAC CE including a TA report is given a lower priority than a MAC CE including a power headroom report.

[0248] In another approach, MAC CEs including TA reports and MAC CEs including power headroom reports are given equal priority, and the UE selects which MAC CE to send to the gNB. In yet another exemplary approach, if the UE's power headroom is less than a threshold (e.g., phrReportingThreshold), the UE prioritizes sending MAC CEs including power headroom reports over TAs that report MAC CEs.

[0249] In another embodiment of this disclosure, conventional cell reselection methods are unsuitable for NTNs with different types of beams, especially due to satellite motion and the very similar RSRP of the serving cell and neighboring cells. Therefore, NTNs require a new method to enhance the reliability of cell reselection.

[0250] Figure 14 An example of a flexible cell reselection framework mechanism 1400 according to an embodiment of this disclosure is shown. Figure 14 The implementation of the flexible cell reselection framework mechanism 1400 shown is for illustrative purposes only. Figure 14 This disclosure is not intended to limit the scope to any particular implementation of the Flexible Cell Reselection Framework 1400.

[0251] like Figure 14 As shown, the gNB receives information such as NTN / beam type and candidate triggers, and sends information about the selected trigger, the selected trigger combination, search criteria, and beam type.

[0252] Figure 15 An example of implementing flexible QoS operation 1500 according to an embodiment of this disclosure is shown. Figure 15 The implementation shown for the flexible QoS operation 1500 is for illustrative purposes only. Figure 15 This disclosure is not intended to limit the scope to any particular implementation of the Flexible QoS Operation 1500.

[0253] like Figure 15 As shown, the eNB / gNB identifies the NTN / beam type and available cell reselection triggers. The eNB / gNB selects a specific trigger and determines one or more trigger combinations. The eNB / gNB broadcasts the NTN / type and trigger combination. Where applicable, the UE avoids measurements to conserve power. When appropriate conditions are met, the UE evaluates the trigger combination and performs cell reselection.

[0254] Figure 16 An exemplary general UE network procedure 1600 for a flexible cell reselection framework in an NTN according to an embodiment of this disclosure is shown. Figure 16The implementation of the overall UE network procedure 1600 for the flexible cell reselection framework in NTN shown is for illustrative purposes only. Figure 16 This disclosure is not intended to limit the scope to any particular implementation of the overall UE network procedure 1600 for the flexible cell reselection framework in NTN.

[0255] In operation of F16S1, the gNB / eNB acquires a configuration including the beam type for each of its cells. In one approach, beam types are distinguished into three types: geostationary, quasi-geostationary (also known as maneuverable beams), and geomotion (i.e., fixed, non-maneuverable beams). For example, geostationary or geosynchronous satellites have geostationary beams that always illuminate the same geographic area. Non-geostationary or geosynchronous satellites (e.g., LEO and MEO) may have geomotion beams that move continuously at different times on a continuous basis and illuminate different geographic areas. Non-geostationary or non-geosynchronous satellites may have quasi-geostationary beams that illuminate a given geographic area for a period of time and then illuminate different geographic areas at different times.

[0256] In Operation F16S2, in an exemplary embodiment of this disclosure, the gNB / eNB sends one or more parameters in system information to help the UE conserve processing power and enable robust cell reselection. In an exemplary method, in Operation F16S2, the gNB / eNB sends one or more of the following parameters: disable-s-IntraSearchP, neighborSearchTimerCellReselection, and parameters associated with a combined trigger supporting cell reselection. In an exemplary implementation, disable-s-IntraSearchP indicates whether the UE should use or ignore the broadcast value of s-IntraSearchP to determine the need for neighbor cell measurements. In another method, disable-s-IntraSearchP indicates whether the UE should use the broadcast values ​​of s-IntraSearchP and IntraSearchQ to determine the need for neighbor cell measurements. In one implementation, the timer neighborSearchTimerCellReselection indicates how long the UE can skip neighbor cell measurements to conserve processing power and increase battery life. For example, when the beam type is quasi-earth fixed in a given NTN, the gNB / eNB transmits the parameters disable-s-IntraSearchP and neighborSearchTimerCellReselection, thereby (i) enabling the UE to detect neighboring cells even when the serving cell RSRP is strong, and (ii) avoiding measurements of neighboring cells after cell reselection to conserve battery life. In an exemplary implementation, the gNB / eNB implicitly or explicitly specifies combined triggering, allowing the UE to evaluate cell reselection triggering conditions. For details on combined triggering, see [link to documentation / document / etc.]. Figure 19 Related descriptions.

[0257] In another approach, the UE is made to not meet the condition "S" by selecting an appropriate s-IntraSearchP value within a specified range (e.g., a high s-IntraSearchP value). rxlev >S IntraSerachP and S qual >S IntraSerachQ "Skipping measurements, thus searching neighboring cells even when the serving cell signal measurement (e.g., RSRP) is good, achieves the effect of disabling s-IntraSearchP. To ensure that the UE does not meet the condition from the s-IntraSearchQ perspective..." rxlev >S IntraSerachP and S qual >S IntraSerachQIn one approach, s-IntraSearchQ may not exist in the system information, making s-IntraSearchP the sole determinant of the condition. In another approach, a suitable s-IntraSearchQ value within a specified range can be selected (e.g., a high s-IntraSearchQ value).

[0258] In F16S3 operation, the UE uses received parameters such as disable-s-IntraSearchP, neighborSearchTimerCellReselection, and parameters related to combined triggering to determine whether it should measure neighboring cells and when it should perform cell reselection.

[0259] Figure 17 An exemplary general UE network procedure 1700 for a flexible cell reselection framework in an NTN according to an embodiment of this disclosure is shown. Figure 17 The implementation of the overall UE network procedure 1700 for the flexible cell reselection framework in NTN shown is for illustrative purposes only. Figure 17 This disclosure is not limited to any particular implementation of the overall UE network procedure 1700 for the flexible cell reselection framework in NTN.

[0260] In operation F17S1 (which is identical to operation F16S1), the gNB / eNB acquires a configuration including the beam type for each of its cells. In one approach, the beam type is distinguished into three types: geostationary, quasi-geostationary (also known as maneuverable beams), and geomotion (i.e., fixed, non-maneuverable beams). For example, geostationary or geosynchronous satellites have geostationary beams that always illuminate the same geographic area. Non-geostationary or geosynchronous satellites (e.g., LEO and MEO) may have geomotion beams that move continuously at different times on a continuous basis and illuminate different geographic areas. Non-geostationary or non-geosynchronous satellites may have quasi-geostationary beams that illuminate a given geographic area for a period of time and then illuminate different geographic areas at different times.

[0261] In an exemplary embodiment of this disclosure, during operation F17S2, the gNB / eNB transmits disable-s-IntraSearchP when needed (e.g., when the beam type is quasi-earth fixed in a given NTN). In an exemplary implementation, the gNB / eNB may transmit this parameter in SIB2, which typically transmits s-IntraSearchP. In another implementation, the gNB / eNB transmits disable-s-IntraSearchP in an SIB other than SIB2. For example, a new SIB defined for the NTN may carry disable-s-IntraSearchP.

[0262] In F17S3 operation, the gNB / eNB transmits the `neighborSearchTimerCellReselection` (when needed) and parameters related to combined triggering for cell reselection in a new SIB, which may be specifically defined for the NTN. In an exemplary implementation, the gNB / eNB transmits `neighborSearchTimerCellReselection` when the beam type is quasi-earth fixed in a given NTN. In an exemplary implementation, the gNB / eNB implicitly or explicitly specifies combined triggering, allowing the UE to evaluate cell reselection triggering conditions. For details on combined triggering, see [link to documentation / reference]. Figure 19 Related descriptions.

[0263] In operation F17S4 (which is the same as operation F16S3), the UE uses received parameters such as disable-s-IntraSearchP, neighborSearchTimerCellReselection, and parameters related to combined triggering to determine whether it should measure neighboring cells and when it should perform cell reselection.

[0264] Figure 18 An exemplary UE procedure 1800 for a flexible cell reselection framework in an NTN according to an embodiment of this disclosure is shown. Figure 18 The implementation of the UE procedure 1800 in the flexible cell reselection framework in the NTN shown is for illustrative purposes only. Figure 18 This disclosure is not intended to limit the scope to any particular implementation of the UE procedure 1800 for the flexible cell reselection framework in NTN.

[0265] In Operation F18S1 (which is the same as Operations F16S1 and F17S1), the gNB / eNB obtains a configuration including the beam type for each of its cells. In one approach, the beam type is distinguished into three types: geostationary, quasi-geostationary (also known as maneuverable beams), and geomotion (i.e., fixed, non-maneuverable beams). For example, geostationary or geosynchronous satellites have geostationary beams that always illuminate the same geographic area. Non-geostationary or geosynchronous satellites (e.g., LEO and MEO) may have geomotion beams that move continuously at different times on a continuous basis and illuminate different geographic areas. Non-geostationary or non-geosynchronous satellites may have quasi-geostationary beams that illuminate a given geographic area for a period of time and then illuminate different geographic areas at different times.

[0266] In an exemplary embodiment of this disclosure, when operating F18S2 (which is similar to...) Figure 16 Operation F16S2, or Figure 17 In the combination of operations F17S2 and F17S3, the gNB / eNB sends one or more parameters in the system information to help the UE save some processing power and enable robust cell reselection. In the exemplary method, in operation F18S2, the gNB / eNB sends one or more of the following parameters: disable-s-IntraSearchP, neighborSearchTimerCellReselection, and parameters related to the combined triggering that supports cell reselection. For details on combined triggering, see [link to relevant documentation]. Figure 19 Related descriptions.

[0267] In operation F18S3, the UE determines that it needs to (i) search for neighboring cells and (ii) measure neighboring cells. In an exemplary implementation, the UE processes conventional parameters such as s-IntraSearchP and s-IntraSearchQ in system information (e.g., SIB2), as well as new parameters such as disable-s-IntraSearchP and neighborSearchTimerCellReselection defined by this disclosure, and decides whether to search for neighboring cells.

[0268] In one exemplary implementation, during operation F18S3, if the gNB has already specified disable-s-IntraSearchP and neighborSearchTimerCellReselection in the system information, the UE starts or restarts the timer after performing cell reselection. Furthermore, if the timer value is less than neighborSearchTimerCellReselection, the UE skips neighbor cell search and avoids measuring neighbor cells. In the exemplary method, when this timer is not running, the UE ignores the value of s-IntraSearchP based on the parameter disable-s-IntraSearchP and searches for neighbor cells. The UE can then detect incoming NTN cells and perform cell reselection when appropriate conditions are met.

[0269] In F18S4 operation, when the UE is searching for and measuring neighboring cells, the UE evaluates one or more trigger conditions and performs cell reselection when one or more trigger conditions are met.

[0270] Figure 19 An exemplary network procedure 1900 for a flexible cell reselection framework in an NTN according to an embodiment of the present disclosure is shown. Figure 19 The implementation of the network procedure 1900 for the flexible cell reselection framework in NTN shown is for illustrative purposes only. Figure 19 This disclosure is not intended to limit the scope to any particular implementation of the network procedure 1900 for the flexible cell reselection framework in NTN.

[0271] In an exemplary embodiment of this disclosure, during operation F19S1, the gNB / eNB makes a decision regarding a specific combination of triggers. The gNB / eNB also determines which conditions the UE should use to assess the need for cell reselection. The given conditions utilize the specific combination of triggers.

[0272] In an exemplary embodiment of this disclosure, in operation F19S2, the gNB specifies one or more of the following in the system information: (i) the number of trigger conditions N (e.g., N = 2); (ii) an identifier for a combined trigger for each trigger condition (e.g., a combined trigger that combines a single trigger of the time elapsed since the last cell reselection (TSLCR) and a neighboring cell signal measurement (NCSM)); and a combination method for the single triggers in the combined trigger (e.g., a logical function such as a logical AND function or a logical OR function); and (iii) a neighboring cell selection method (e.g., grade-based or non-grade-based). Following the description of operation F19S3, details of the trigger combinations and trigger conditions are given below.

[0273] In the exemplary method, the gNB / eNB can define two trigger conditions (i.e., N=2) for quasi-Earth fixed-beam trigger condition 1 and trigger condition 2. To define trigger condition 1, the gNB designates the TSLCR and NCSM as a single trigger and specifies a logical "AND" function to combine the TSLCR and NCSM. To define trigger condition 2, the gNB designates the Neighbor Serving Cell Signal Measurement (NSCSM) as a single trigger and a trigger combination (therefore, a logical combination function is not required in this example). The exemplary method described herein can be extended to any appropriate number of trigger conditions and any appropriate number of single triggers for a given trigger combination. Furthermore, for a single trigger based on a neighboring cell (which is part of a combined trigger), an offset based on satellite motion can be applied according to the decision of the gNB / eNB.

[0274] In another exemplary approach, the set of all conditions (and associated trigger combinations) is fully defined in the specification, and the gNB / eNB indicates in the system information which of these conditions the UE should use when performing cell reselection (e.g., conditions 1 and 3 out of a set of 5 conditions).

[0275] In yet another exemplary approach, the specification fully defines a set of all triggering conditions (and associated triggering combinations), and defines the applicability of a given triggering condition (e.g., conditions 1 and 3 applicable to earth-fixed beams). In this case, in the exemplary approach, the gNB / eNB indicates the "beam type" in the system information. The UE then utilizes the applicable conditions based on the beam type.

[0276] In another approach, triggering conditions applicable to both GNSS-capable and non-GNSS-capable UEs are identified, allowing the UE to assess the relevant triggering conditions based on its GNSS capabilities. This applicability of the GNSS capabilities of UEs for one or more relevant triggering conditions can be explicitly specified in the specification or identified by the gNB / eNB in ​​system information via appropriate indicators or flags for a given triggering condition.

[0277] In operation F19S3, the UE measures the quantity designated as the trigger and evaluates the applicable conditions for using one or more combined triggers. The UE performs cell reselection if any condition is met.

[0278] Single trigger and trigger combination

[0279] Different trigger values ​​are applicable to different types of beams. The following specifies individual triggers and trigger combinations related to cell reselection in NTN.

[0280] The one-way propagation delay (OPD) of the serving cell (OPDSC) is used as a trigger. The one-way propagation delay (OPD) between the NTN platform (e.g., satellite or HAPS) and the UE can be used as an indirect indicator of the distance between the NTN platform and the UE. When the OPD for the serving cell is large (e.g., for fixed earth beams), the UE is close to the edge of the serving cell. A large OPD indicates the need for cell reselection (e.g., for fixed earth beams). For example, "if (OPDSC > Threshold_PropagationDelayServingCell_CellReselection)" can be used as part of a combined trigger under trigger conditions. The UE can estimate the gNB-to-UE delay by observing the time difference between (i) the moment when the timestamped SIB is received at the UE and (ii) the moment when the timestamped SIB is created by the gNB. The UE can then calculate the OPDSC by subtracting the gNB-to-platform delay (e.g., total feeder link delay) from the gNB-to-UE delay. The OPDSC can be used as a useful trigger for both fixed earth beams and moving earth beams. In an exemplary embodiment of this disclosure, the gNB / eNB broadcasts Threshold_PropagationDelayServingCell_CellReselection in system information.

[0281] As a trigger, the distance between the UE and a given cell (i.e., the serving cell or a neighboring cell) can be defined as the distance between the UE and the cell center, where the cell center is a reference point in the center of the beam coverage area of ​​the serving cell and the neighboring cell.

[0282] The distance-to-platform in the serving cell (DTPSC) is used as the trigger. The distance between the NTN platform and the UE in the serving cell can be used as the trigger. When the DTPSC is large, the UE is close to the edge of the serving cell. A large distance indicates the need for cell reselection (e.g., for fixed earth beams). For example, "if (DTPSC > Threshold_Distance_ServingCell_CellReselection)" can be used as part of a combined trigger condition. A GNSS-capable UE can estimate the distance to the platform by utilizing its GNSS location and the platform GNSS location received in the system information. This distance can be used as a useful trigger for fixed earth beams. In an exemplary embodiment of this disclosure, the gNB / eNB broadcasts Threshold_Distance_ServingCell_CellReselection in the system information.

[0283] The time elapsed since the last cell reselection (TSLCR) is used as the trigger. The time elapsed since the last cell reselection can be used as a trigger (e.g., for quasi-earth fixed beams). For example, "if (TSLCR > Threshold_Time_CellReselection)" can be used as part of a combined trigger condition. When the UE performs a cell reselection to a new cell, the UE starts or restarts the TSLCR timer. In an exemplary embodiment of this disclosure, the gNB / eNB broadcasts Threshold_Time_CellReselection in the system information.

[0284] The TSLCR method is equivalent to the method in the case of quasi-Earth fixed beams (i.e., fixed beams for LEO), where time is represented as the service time or dwell time of a cell in a given geographic area. Using an absolute timestamp as the trigger is another equivalent of the TSLCR method.

[0285] The serving cell elevation angle (SCEA) is used as the trigger. The serving cell elevation angle can be used to trigger cell reselection. A large SCEA means the UE is close to the edge of the serving cell, thus indicating that cell reselection is needed. For example, "if (SCEA > Threshold_ServingElevationAngle_NTN)" can be used as part of a combined trigger condition. In this formula, the elevation angle is 90° when the NTN cell's satellite is directly overhead, and it increases as the NTN cell or beam continues to move away from the UE. In an exemplary embodiment of this disclosure, the gNB / eNB broadcasts Threshold_ServingElevationAngle_NTN in its system information.

[0286] The Neighboring Cell Elevation Angle (NCEA) is used as the trigger. The elevation angle of the neighboring cell can be used to trigger cell reselection. A large NCEA means that the UE is near the edge of an upcoming neighboring cell, thus indicating that cell reselection is required. For example, "if (NCEA > Threshold_NeighborElevationAngle_NTN)" can be used as part of a combined trigger condition. In this formula, the elevation angle is 90° when the satellite of the NTN cell is directly overhead, and it increases as the NTN cell or beam continues to move away from the UE. In an exemplary embodiment of this disclosure, the gNB / eNB broadcasts Threshold_NeighborElevationAngle_NTN in the system information.

[0287] Absolute Signal Measurement Difference (ASMD) is used as a trigger. The absolute difference between signal measurements of the serving cell and the neighboring cell can be used to trigger cell reselection. A small ASMD indicates that the UE is near the boundary between the upcoming neighboring cell and the serving cell, thus indicating that cell reselection is required. For example, "if for timeToTrigger, (ASMD<Threshold_AbsoluteDifference_ServingNeighbor_NTN)" can be used as part of a combined trigger under the triggering condition. The timeToTrigger can be set to zero. Exemplary signal measurements include RSRP, RSRQ and SINR. In an exemplary implementation of the present disclosure, the gNB / eNB broadcasts Threshold_AbsoluteDifference_ServingNeighbor_NTN in system information.

[0288] Neighboring Cell Signal Measurement (NCSM) is used as a trigger. Neighboring cell signal measurement can be used to trigger cell reselection. A strong NCSM indicates that the UE has a satisfactory radio environment with the neighboring cell. For example, "if for timeToTrigger, (NCSM>Threshold_SignalMesurement_Neighbor_NTN)" can be used as part of a combined trigger under the triggering condition. The timeToTrigger can be set to zero. Exemplary signal measurements include RSRP, RSRQ and SINR. In an exemplary implementation of the present disclosure, the gNB / eNB broadcasts Threshold_SignalMesurement_Neighbor_NTN in system information.

[0289] Neighboring and Serving Cell Signal Measurement (NSCSM) is used as a trigger. Both Neighboring Cell Signal Measurement (NCSM) and Serving Cell Signal Measurement (SCSM) can be used as part of the trigger for cell reselection. The combination of a strong NSM and a weak SCM indicates that the UE has a better radio channel environment with the neighboring cell than with the serving cell, so cell reselection is desired. For example, "if for timeToTrigger, ((NCSM-SCSM)>Threshold_SignalMesurement_Serving_Neighbor_NTN)" can be used as part of a combined trigger under the triggering condition. The timeToTrigger can be set to zero. Exemplary signal measurements include RSRP, RSRQ and SINR. In an exemplary implementation of the present disclosure, the gNB / eNB broadcasts Threshold_SignalMesurement_Serving_Neighbor_NTN in system information.

[0290] Enhancement triggered by a single neighboring cell

[0291] In exemplary embodiments of this disclosure, an offset based on satellite motion can be added to the conditions described above based on non-signal measurement neighbor cell triggering parameters (e.g., elevation angle, distance, and propagation delay) to encourage or prevent cell reselection for a given neighbor cell. For example, a positive offset is used to encourage cell reselection for a given neighbor cell when entering a neighbor cell. A zero offset will neither encourage nor prevent cell reselection for a neighbor cell. A negative offset can be used to prevent cell reselection for a given neighbor cell when leaving a neighbor cell.

[0292] The offset can be reversed depending on its position in the equation that defines the trigger condition; for example, a positive offset is used to prevent cell reselection of neighboring cells rather than to encourage cell reselection.

[0293] In another possible implementation, to prevent cell reselection for neighboring cells not specified in the neighbor list, the UE may be prevented from evaluating neighboring cells not in the neighbor list for cell reselection and handover purposes. In an exemplary method, the UE can still search for and measure neighboring cells not listed in the neighbor list to support Ad Hoc Network (SON) functionality and Drive Minimum Test (MDT).

[0294] In the exemplary method, the basic trigger "if (triggerQuantityForANeighbor>Threshold_TriggerQuantity)" can be modified to "if (triggerQuantityForANeighbor+Δ)>Threshold_TriggerQuantity)" to reflect the offset Δ based on satellite motion. In the exemplary method, within a given cell, the gNB / eNB broadcasts the Δ value of the target neighboring cell.

[0295] As a specific example, as part of a combined triggering condition, the basic trigger “if (NCEA>Threshold_NeighborElevationAngle_NTN)” can be modified to “if ((NCEA+Δ)>Threshold_NeighborElevationAngle_NTN)” to reflect the offset Δ based on satellite motion.

[0296] In an exemplary implementation, when the UE performs a search for neighboring cells not mentioned in the system information, in an exemplary method of preventing cell reselection of that neighboring cell, a default offset (e.g., a negative offset) can be defined and broadcast by the gNB / eNB. In another implementation, the default value can be explicitly defined in the specification.

[0297] Combined triggers and trigger conditions

[0298] In terrestrial networks (TN), cell reselection is typically based on RSRP and RSRQ. However, in NTNs, signal measurements such as RSRP can be similar for both the serving cell and neighboring cells. Therefore, to enhance the reliability of the cell reselection process, multiple triggers, including NTN-specific triggers, can be combined.

[0299] In embodiments of this disclosure, previously defined number-based individual partial triggers (i.e., single triggers) are combined in a flexible manner to create multiple combined triggers for a given triggering condition.

[0300] In embodiments of this disclosure, in order to create a combined trigger (“Trigger A”), the following logical AND function is used to combine a single trigger “OPDSC trigger” with a “NCSM trigger”.

[0301] For any neighboring cell, ["if (OPDSC>Threshold_PropagationDelayServingCell_CellReselection)"] AND

[0302] If for timeToTrigger, ((NSM+Δ)>Threshold_SignalMesurement_Neighbor_NTN)], then cell reselection is triggered, and the neighbor cell selection process is executed.

[0303] This combination trigger "A" applies to Earth motion beams. Using a satellite motion-based neighbor list prevents incorrect cell reselection (i.e., cell reselection of neighboring cells far from the UE).

[0304] The first part of the combined trigger "A" indicates that the UE is far from the center of the serving cell and close to the edge of the serving cell, indicating that cell reselection is required. The second part of the combined trigger indicates that neighboring cells can provide the UE with a suitable radio environment for communication.

[0305] In embodiments of this disclosure, in order to create a combined trigger (“Trigger B”), the following logical AND function is used to combine a single trigger “DTPSC trigger” with an “NCSM trigger”.

[0306] For any neighboring cell, ["if (DTPSC>Threshold_Distance_ServingCell_CellReselection)"] AND

[0307] If for timeToTrigger, ((NSM+Δ)>Threshold_SignalMesurement_Neighbor_NTN)], then cell reselection is triggered, and the neighbor cell selection process is executed.

[0308] This combination trigger "B" applies to Earth motion beams. Using a satellite motion-based neighbor list prevents incorrect cell reselection (i.e., cell reselection of neighboring cells far from the UE).

[0309] The first part of the combined trigger "B" indicates that the UE is far from the center of the serving cell and close to the edge of the serving cell, indicating that cell reselection is required. The second part of the combined trigger indicates that neighboring cells can provide the UE with a suitable radio environment for communication.

[0310] Combining trigger "B" is more direct than combining trigger "A" because it utilizes the distance itself rather than the propagation delay as a distance proxy.

[0311] In embodiments of this disclosure, in order to create a combined trigger (“Trigger C”), the following logic function is used to combine individual triggers of “TSCR trigger” and “NCSM trigger”.

[0312] For any neighboring cell, ["if (TSLCR > Threshold_Time_CellReselection)"] AND

[0313] If for timeToTrigger, ((NSM+Δ)>Threshold_SignalMesurement_Neighbor_NTN)], then cell reselection is triggered, and the neighbor cell selection process is executed.

[0314] This combination trigger "C" applies to both quasi-Earth fixed beams and Earth motion beams. A satellite motion-based neighbor list is used to prevent incorrect cell reselection (i.e., cell reselection of neighboring cells far from the UE).

[0315] The first part of the combined trigger "C" indicates that sufficient time has elapsed since the last cell reselection and that a suitable neighboring cell for cell reselection should arrive soon. The second part of the combined trigger indicates that the neighboring cell can provide the UE with a suitable radio environment for communication.

[0316] Even for UEs without GNSS capabilities, the combination trigger "C" is useful.

[0317] In embodiments of this disclosure, in order to create a combined trigger (“Trigger D”), the following logical AND function is used to combine a single trigger “SCEA trigger” with a “NCSM trigger”.

[0318] For any neighboring cell, ["if (SCEA>Threshold_ServingElevationAngle_NTN)"] AND

[0319] [For timeToTrigger, if ((NSM+Δ)>Threshold_SignalMesurement_Neighbor_NTN)], then cell reselection is triggered, and the neighbor cell selection process is executed.

[0320] This combination trigger "D" applies to both quasi-Earth fixed beams and Earth motion beams. A satellite motion-based neighbor list is used to prevent incorrect cell reselection (i.e., cell reselection of neighboring cells far from the UE).

[0321] The first part of the combined trigger "D" indicates that the UE is far from the center of the serving cell and close to the edge of the serving cell, indicating that cell reselection is required. The second part of the combined trigger indicates that neighboring cells can provide the UE with a suitable radio environment for communication.

[0322] In embodiments of this disclosure, in order to create a combined trigger (“Trigger E”), the following logical AND function is used to combine a single trigger “NCEA trigger” with a “NCSM trigger”.

[0323] For any neighboring cell, ["if (NCEA>Threshold_NeighborElevationAngle_NTN)"] AND

[0324] [For timeToTrigger, if ((NSM+Δ)>Threshold_SignalMesurement_Neighbor_NTN)], then cell reselection is triggered, and the neighbor cell selection process is executed.

[0325] This combination trigger "E" applies to both quasi-Earth fixed beams and Earth motion beams. A satellite motion-based neighbor list is used to prevent incorrect cell reselection (i.e., cell reselection of neighboring cells far from the UE).

[0326] The first part of the combined trigger "E" indicates that the UE is approaching a neighboring cell, indicating that cell reselection is required. The second part of the combined trigger indicates that the neighboring cell can indeed provide a suitable radio environment for communication to the UE.

[0327] In embodiments of this disclosure, in order to create a combined trigger (“trigger F”), the following logical AND function is used to combine individual triggers “SCEA trigger”, “NCEA trigger”, and “NCSM trigger”.

[0328] For any neighboring cell, ["if (SCEA>Threshold_ServingElevationAngle_NTN)"] AND

[0329] [“if (NCEA>Threshold_NeighborElevationAngle_NTN)”] AND

[0330] [For timeToTrigger, if ((NSM+Δ)>Threshold_SignalMesurement_Neighbor_NTN)], cell reselection is triggered, and the neighboring cell selection procedure is performed.

[0331] This combined trigger "F" applies to quasi-earth fixed beams and earth moving beams. The use of a neighbor list based on satellite motion prevents incorrect cell reselection (i.e., cell reselection to a neighboring cell far away from the UE).

[0332] The first part of combined trigger "F" indicates that the UE is moving away from the serving cell, the second part of combined trigger "F" indicates that the UE is approaching the incoming neighboring cell, indicating that cell reselection is required. The third part of combined trigger "F" indicates that the neighboring cell can indeed provide the UE with a radio environment suitable for communication.

[0333] In embodiments of the present disclosure, as a special case, to create a combined trigger ("Trigger G"), "ASMD trigger" is used as an independent individual trigger without being combined with any other individual triggers.

[0334] For any neighboring cell, [for timeToTrigger, if (ASMD<Threshold_AbsoluteDifference_ServingNeighbor_NTN)], cell reselection is triggered, and the neighboring cell selection procedure is performed. To prevent frequent cell reselection caused by a UE that satisfies the same trigger condition "G" within a short period of time after cell reselection, a timer such as "TriggerGTimer" is started after cell reselection. When the timer "TriggerGTimer" is running, the trigger condition "G" is not evaluated for the purpose of cell reselection. Note that other trigger conditions (i.e., non-trigger G conditions) are still evaluated by the UE.

[0335] This combined trigger "G" applies to earth fixed beams, quasi-earth fixed beams and earth moving beams. The use of a neighbor list based on satellite motion prevents incorrect cell reselection (i.e., cell reselection to a neighboring cell far away from the UE).

[0336] Compared to traditional cell reselection triggers, this trigger can accelerate cell reselection by allowing neighboring cells to be reselected weaker or stronger than the serving cell.

[0337] In embodiments of this disclosure, as a special case, in order to create a combined trigger (“trigger H”), the “NSCSM trigger” is used as a standalone single trigger, without being combined with any other single trigger.

[0338] For any neighboring cell, [if for timeToTrigger, ((NCSM-SCSM)>Threshold_SignalMesurement_Serving_Neighbor_TN)], then cell reselection is triggered, and the neighboring cell selection process is executed.

[0339] This combination trigger "H" applies to Earth-fixed beams, quasi-Earth-fixed beams, and Earth-motion beams. A satellite motion-based neighbor list is used to prevent incorrect cell reselection (i.e., cell reselection of neighboring cells far from the UE).

[0340] This trigger is intended to serve as a mechanism to correct cell reselection errors. For example, if a single trigger or a combination of triggers results in a cell reselection for an incorrect neighboring cell (which becomes the serving cell), but that neighboring cell is clearly superior to the serving cell, then a cell reselection for that superior candidate cell can be performed.

[0341] In embodiments of this disclosure, the gNB / eNB in ​​the system information specifies multiple trigger conditions. A trigger condition is associated with one of a combined trigger, and a combined trigger typically combines two or more individual triggers. As a special case, a combined trigger may have only one individual trigger.

[0342] In an exemplary embodiment of this disclosure, cell reselection is triggered when one or more triggering conditions are met for any neighboring cells. This means using a logical OR function to combine different triggering conditions. In another embodiment of this disclosure, a logical AND function can be used to combine multiple triggering conditions to make a cell reselection decision.

[0343] In one exemplary method, the neighboring cells evaluated for the triggering condition are explicitly specified in the system information. In another exemplary method, the neighboring cells evaluated by the UE for the triggering condition are detected autonomously by the UE and are not explicitly specified in the system information.

[0344] In an exemplary implementation of the method, the propagation delay difference between the serving cell and neighboring cells is combined with one or more other triggers (such as neighboring cell RSRP and time / timer) to create a more reliable combined trigger for cell reselection.

[0345] Neighboring cell selection method

[0346] In the exemplary method, when multiple neighboring cells meet the cell reselection triggering condition, the neighboring cell with the highest ranking is selected from these neighboring cells (see below for details).

[0347] In an exemplary embodiment of this disclosure, the cell ranking criterion Rs for the serving cell and the cell ranking criterion Rn for neighboring cells are calculated by taking into account the offset based on satellite motion:

[0348] R s =Q meas，s +Q hyst -Qoffset temp

[0349] R n =Q meas，n -Qoffset-Qoffset temp+Δ

[0350] (R s =Q meas,s +Q Hyst -Qoffset temp Rn = Q meas,n -Qoffset-Qoffset temp +Δ)

[0351] In an exemplary implementation, after cell reselection is triggered, cell reselection is performed on the neighboring cell with the highest ranking Rn without considering Rs and by setting Δ to zero.

[0352] In another exemplary implementation, after cell reselection is triggered, Δ is set to zero, and if (Rn>Rs) or (Rn>=Rs), reselection is performed on the neighboring cell with the highest ranking Rn.

[0353] In another exemplary implementation, after triggering cell reselection, if the configured Δ value is used for different neighboring cells, and if (Rn>Rs) or (Rn>=Rs), then reselection is performed on the neighboring cell with the highest ranking Rn.

[0354] In another exemplary embodiment of this disclosure, the cell ranking criterion Rn of neighboring cells is calculated by considering the offset based on satellite motion and the number of trigger conditions satisfied by neighboring cells (here referred to as NumTriggerConditions), where α is the excitation used to satisfy the trigger conditions specified by the gNB / eNB in ​​the system information:

[0355] Rn ＝ Q meas，n-Qoffset-Qoffset temp +Δ+(numTriggerConditions*α)

[0356] (Rn=Q meas,n -Qoffset-Qoffset temp +Δ+(nnmTriggerConditions*α))

[0357] In this case, after the triggering condition is met, cell reselection is performed on the neighboring cell with the highest ranking Rn without considering Rs.

[0358] In another approach, each triggering condition can have its own weight α.

[0359] Signaling based on satellite motion parameters

[0360] In embodiments of this disclosure, in operations F16S2, F17S2, F18S2 and / or F19S2, an offset based on satellite motion is specified for each neighboring cell.

[0361] In another embodiment of this disclosure, in operations F7S2, F8S2, F9S2 and / or F10S2, satellite motion-based offsets are specified for each group of adjacent cells to reduce overhead.

[0362] In another embodiment of this application, for quasi-Earth fixed beams, the type of neighboring cell is indicated based on the movement of neighboring cells using one or more of the following names: "Entering a Neighboring Cell," "Current Geographic Neighboring Cell," and "Entering an Overlapping Neighboring Cell." The name "Entering a Neighboring Cell" means that the neighboring cell is a geographic neighboring cell of a cell that will provide substantially the same overlapping coverage to the current serving cell. The name "Current Geographic Neighboring Cell" means that the neighboring cell is a geographic neighboring cell of the current serving cell. The name "Entering an Overlapping Neighboring Cell" means that the neighboring cell is a cell that will provide substantially the same overlapping coverage to the current serving cell.

[0363] For quasi-Earth fixed beams, these neighbor cell names can be used by the UE to prioritize the selection of neighbor cells of a given type.

[0364] In the exemplary method, a specific coefficient for the neighboring cell name is used in conjunction with a given threshold β to achieve the priority shown in the equation below.

[0365] R n =Q meas,n -Qoffset-Qoffset temp+C*β

[0366] (Rn=Qmeas,n -Qoffset-Qoffset temp +C*β)

[0367] The parameter β can be used to avoid back-and-forth jumping during cell reselection, and the coefficient c is used to set different priorities for different types of cells. For example, (i) if the neighboring cell "n" is "entering overlapping neighboring cells", c can be set to "3"; (ii) if the neighboring cell "n" is "entering neighboring cells", c can be set to "2"; (iii) if the neighboring cell "n" is "currently geographically neighboring cells", c can be set to "1". A larger positive value of c indicates that the neighboring cell is selected with priority, while a smaller positive value of c indicates that the neighboring cell is not selected with priority.

[0368] The parameter β and the coefficient c can be specified by gNB in ​​operations F16S2, F17S2, F18S2 and / or F19S2.

[0369] In another embodiment of this disclosure, for the Earth motion beam, the type of neighboring cell is indicated based on the motion of neighboring cells using one or more of the following names: "Entering Neighboring Cell," "Neutral Neighboring Cell," and "Leaving Neighboring Cell." The name "Entering Neighboring Cell" means that the beam of the neighboring cell is moving towards the geographic area currently served by the serving cell, and is designed to encourage cell reselection for that neighboring cell. The name "Neutral Neighboring Cell" means that, from the perspective of beam motion, neither cell reselection for that neighboring cell is encouraged nor discouraged. The name "Leaving Neighboring Cell" means that the beam of the neighboring cell is moving away from the geographic area currently served by the serving cell, and is designed to discourage cell reselection for that neighboring cell.

[0370] For Earth motion beams, these neighboring cell names can be used by the UE to prioritize the selection of neighboring cells of a given type.

[0371] In the exemplary method, a specific coefficient for the neighboring cell name is used in conjunction with a given threshold γ to achieve the priority shown in the equation below.

[0372] R n =Q meas,n -Qoffset-Qoffset temp+d*γ

[0373] (Rn=Q meas,n -Qoffset-Qoffset temp +d*γ)

[0374] The parameter γ is used to avoid back-and-forth jumping during cell reselection, and the coefficient d is used to set different priorities for different types of cells. For example, (i) if the neighboring cell "n" is "entering a neighboring cell", d can be set to "1"; (ii) if the neighboring cell "n" is "neutral neighboring cell", d can be set to "0"; (iii) if the neighboring cell "n" is "leaving a neighboring cell", d can be set to "-1". A positive (or large positive) value of d indicates that the neighboring cell is selected with priority, while a negative value of d indicates that the neighboring cell is not selected with priority.

[0375] The parameter γ and the coefficient d can be specified by gNB in ​​operations F16S2, F17S2, F18S2 and / or F19S2.

[0376] Additional independent / single and combined triggers

[0377] The interior area (IA) is used as a trigger. Because the coverage of satellite beams over an area of ​​the Earth's surface is elliptical (rather than circular), the UE can determine whether it is inside or outside the IA of a given beam or cell. In the case of Earth-fixed beams and Earth-moving beams, the UE can use the standard "UE is outside the interior area of ​​the serving cell" (or equivalently, "UE is outside the interior area of ​​the serving beam of the serving cell") as a trigger to perform cell reselection. If the UE is outside the IA, it indicates that the UE is in the overlapping area of ​​adjacent cells (i.e., the boundary of two or more cells), and it is possible for the UE to find a suitable adjacent cell for cell reselection. The UE can use its location (e.g., latitude and longitude) along with the center of the elliptical area, its major axis (or semi-major axis), and its minor axis (or semi-minor axis) to determine whether it is inside or outside the IA.

[0378] For example, the UE uses the cell center (i.e., the reference point denoted as (cx, cy)), the major axis of the IA (major axis = 2a, where a = major semi-axis) and the minor axis of the IA (minor axis = 2b, where b = minor semi-axis) and its GNSS-based position (ueX, ueY) to determine whether it is within the IA.

[0379] The UE determines whether it is inside (or on) the IA based on a specific implementation. One possible method is as follows: The UE calculates the following quantity: Comparison value = (ueX - cx) 2 / a 2 +(ueY-cy) 2 / b 2 If the comparison value is less than or equal to 1, then the UE is inside or on the IA. Otherwise, the UE is outside the IA.

[0380] In embodiments of this disclosure, the gNB broadcasts the center, major axis (or semi-major axis), and minor axis (or semi-minor axis) of the elliptical region of its beam during operations F16S2, F17S2, F18S2, and / or F19S2. In an exemplary method, independent internal region triggers are combined with one or more previously designated independent triggers to create a combined trigger for cell reselection.

[0381] In embodiments of this disclosure, in order to create a combined trigger (“Trigger I”), the following logical AND function is used to combine a single trigger “Internal Region Trigger” and “NCSM Trigger”.

[0382] For any neighboring cell, ["if the UE is outside the inner region of the serving beam of the serving cell")] AND

[0383] If for timeToTrigger, ((NCSM+Δ)>Threshold_SignalMesurement_Neighbor_NTN)], then cell reselection is triggered, and the neighbor cell selection process is executed.

[0384] This combination trigger "I" is applicable to Earth-fixed beams, quasi-Earth-fixed beams, and Earth-moving beams.

[0385] The first part of the combined trigger "I" indicates that the UE is far from the center of the serving cell and close to the edge of the serving cell, indicating that cell reselection is required. The second part of the combined trigger indicates that neighboring cells can provide the UE with a suitable radio environment for communication.

[0386] In embodiments of this disclosure, in order to create a combined trigger (“Trigger J”), the following logical AND function is used to combine a single trigger “Internal Area Trigger”, “Serving Cell RSRP / RSRQ Trigger”, and “NCSM Trigger”.

[0387] For any neighboring cell, ["if the UE is outside the inner region of the serving beam of the serving cell")] AND

[0388] If the serving cell RSRP / RSRQ <RSRP / RSRQ_Threshold”]

[0389] If for timeToTrigger, ((NSM+Δ)>Threshold_SignalMesurement_Neighbor_NTN)], then cell reselection is triggered, and the neighbor cell selection process is executed.

[0390] This combination trigger "J" is applicable to Earth-fixed beams, quasi-Earth-fixed beams, and Earth-moving beams.

[0391] The first two parts of the combined trigger “J” indicate that the UE is far from the center of the serving cell and close to the edge of the serving cell, indicating that cell reselection is required. The last or third part of the combined trigger indicates that a neighboring cell can provide the UE with a suitable radio environment for communication.

[0392] In embodiments of this disclosure, in order to create a combined trigger (“trigger K”), the following logical AND function is used to combine a single trigger “serving cell RSRP / RSRQ trigger” and “NCSM trigger”.

[0393] For any neighboring cell, ["if the serving cell RSRP / RSRQ"] <RSRP / RSRQ_Threshold”]

[0394] If for timeToTrigger, ((NSM+Δ)>Threshold_SignalMesurement_Neighbor_NTN)], then cell reselection is triggered, and the neighbor cell selection process is executed.

[0395] This combination trigger "K" is applicable to Earth-fixed beams, quasi-Earth-fixed beams, and Earth-moving beams.

[0396] The first part of the combined trigger "K" indicates that the UE is far from the center of the serving cell and close to the edge of the serving cell, indicating that cell reselection is required. The second part of the combined trigger indicates that neighboring cells can provide the UE with a suitable radio environment for communication.

[0397] The distance from the serving cell center to the UE (SCCUD) is used as the trigger. The UE can calculate the distance between itself and the center of the serving cell to determine how close or far it is from the center of the serving cell (or the center of the serving cell's beam). If the UE is far from the center of the serving cell, it indicates that the UE is in an adjacent overlapping area (i.e., the boundary between two or more cells), and it is possible for the UE to find a suitable neighboring cell for cell reselection.

[0398] In embodiments of this disclosure, the gNB broadcasts the center and serving cell distance thresholds of the serving cell in operations F16S2, F17S2, F18S2, and / or F19S2. In an exemplary method, an independent SCCUD trigger is combined with one or more previously specified independent triggers to create a combined trigger for cell reselection.

[0399] In embodiments of this disclosure, in order to create a combined trigger (“trigger L”), the following logical AND function is used to combine a single trigger “SCCUD trigger” and “NCSM trigger”.

[0400] For any neighboring cells, [if "UE serving cell center distance > serving cell distance threshold"] AND

[0401] If for timeToTrigger, ((NCSM+Δ)>Threshold_SignalMesurement_Neighbor_NTN)], then cell reselection is triggered, and the neighbor cell selection process is executed.

[0402] This combination trigger "L" is applicable to Earth-fixed beams, quasi-Earth-fixed beams, and Earth-moving beams.

[0403] The first part of the combined trigger "L" indicates that the UE is far from the center of the serving cell and close to the edge of the serving cell, indicating that cell reselection is required. The second part of the combined trigger indicates that neighboring cells can provide the UE with a suitable radio environment for communication.

[0404] In embodiments of this disclosure, in order to create a combined trigger (“trigger M”), the following logical AND function is used to combine individual triggers “RSRP / RSRQ trigger”, “SCCUD trigger”, and “NCSM trigger”.

[0405] For any neighboring cell, ["if the serving cell RSRP / RSRQ"] <RSRP / RSRQ_Threshold”]

[0406] ["If the UE's serving cell center distance > serving cell distance threshold")] AND

[0407] If for timeToTrigger, ((NCSM+Δ)>Threshold_SignalMesurement_Neighbor_NTN)], then cell reselection is triggered, and the neighbor cell selection process is executed.

[0408] This combination trigger "M" is applicable to Earth-fixed beams, quasi-Earth-fixed beams, and Earth-moving beams.

[0409] The first two parts of the combined trigger “M” indicate that the UE is far from the center of the serving cell and close to the edge of the serving cell, indicating that cell reselection is required. The third or last part of the combined trigger indicates that a neighboring cell can provide the UE with a suitable radio environment for communication.

[0410] Triggering is based on Remaining Serving Time (RST). A UE may calculate the retainingServingTime of the current serving cell by subtracting the current time from endServingTime and comparing the result with retainingServingTimeThreshold. If less time remains, the UE will trigger cell reselection.

[0411] In the embodiments of the present disclosure, a gNB broadcasts endServingTime and remainingServingTimeThreshold in operations F16S2, F17S2, F18S2 and / or F19S2. In an exemplary method, the independent RST trigger is combined with one or more independent triggers specified previously to create a combined trigger for cell reselection. This may be applied to quasi-geostationary beams and feeder link switching.

[0412] In the embodiments of the present disclosure, to create a combined trigger ("Trigger N"), the individual trigger "RST trigger" and "NCSM trigger" are combined using a logical AND function as follows.

[0413] For any neighboring cell, ["if retainingServingTime < retainingServingTimeThreshold")] AND

[0414] [if for timeToTrigger, ((NCSM + Δ) > Threshold_SignalMesurement_Neighbor_NTN)], cell reselection is triggered, and a neighboring cell selection procedure is performed.

[0415] This combined trigger "N" is applicable to quasi-geostationary beams and earth-moving beams, as well as feeder link switching for quasi-geostationary beams and earth-moving beams.

[0416] The first part of the combined trigger "N" indicates that cell reselection is required. The second part of the combined trigger indicates that the neighboring cell can provide the UE with a suitable radio environment for communication.

[0417] In the embodiments of the present disclosure, to perform fallback cell reselection ("Trigger O"), the UE evaluates the following condition.

[0418] [if "retainingServingTime < fallbackThreshold"], cell reselection is triggered, and the UE performs cell reselection to a fallback neighboring cell.

[0419] This combination trigger "O" is applicable to quasi-geostationary beam and feeder link switches, and is used for quasi-geostationary beam and geostationary beam.

[0420] In embodiments of this disclosure, the gNB broadcasts the fallback threshold and identifier for the fallback neighboring cell in operations F16S2, F17S2, F18S2 and / or F19S2.

[0421] In another implementation, the fallback threshold is specified as endServingTime-TimeMargin, and the time margin (TimeMargin) is broadcast in the system information instead of the fallback threshold.

[0422] In embodiments of this disclosure, when cell reselection is not triggered by any condition other than trigger "O", the UE performs cell reselection on the fallback neighboring cell. In another method, when no neighboring cell has a better class than the current serving cell, the UE performs cell reselection on the fallback neighboring cell. When trigger condition "O" is met, cell reselection on the fallback neighboring cell is performed.

[0423] In an embodiment of this disclosure, in order to perform fallback cell reselection (“trigger P”), the UE evaluates the following conditions.

[0424] If "dwellTime > maxServingTimeThreshold", then cell reselection is triggered, and the UE performs cell reselection on the fallback neighboring cell. The variable dwell time is the time elapsed since the cell selection or cell reselection of the current serving cell, and maxServingTimeThreshold specifies the maximum period of a given point on the Earth's surface covered by the Earth motion beam.

[0425] This combination triggers "P" for Earth motion beams.

[0426] In embodiments of this disclosure, the gNB broadcasts the maxServingTimeThreshold and the identifier of the fallback neighboring cell in operations F16S2, F17S2, F18S2 and / or F19S2.

[0427] In embodiments of this disclosure, when cell reselection is not triggered by any condition other than trigger "P", the UE performs cell reselection on the fallback neighboring cell. In another method, when no neighboring cell has a better class than the current serving cell, the UE performs cell reselection on the fallback neighboring cell; when trigger condition "P" is met, cell reselection on the fallback neighboring cell is performed.

[0428] Figure 20A flowchart of a method 2000 for operating a user equipment (UE) according to an embodiment of the present disclosure is shown. The user equipment (UE) can be performed by a UE (e.g., UE 116). Figure 20 The embodiments of method 2000 shown are for illustrative purposes only. Figure 20 This disclosure is not intended to limit the scope to any particular implementation.

[0429] like Figure 20 As shown, method 2000 begins with operation 2002. In operation 2002, the UE (e.g., as...) Figure 1 The system information shown in 111-116 includes: information corresponding to the location coordinates of the non-terrestrial network (NTN) gateway; information corresponding to the processing delay between the UE and the base station (BS); and information corresponding to the location of the reference point.

[0430] In Operation 2004, the UE determines timing advance based on the timing difference between the reference point position and the BS.

[0431] In Operation 2006, the UE sends a timing advance report based on the determined timing advance.

[0432] In one implementation, the UE may autonomously send a timing advance report when conditions are met or when performing random access; send a timing advance report periodically; or send a timing advance report in response to a command from the BS.

[0433] In one implementation, the UE sends a timing advance report via a Radio Resource Control (RRC) message or via a Media Access Control (MAC) control element (CE).

[0434] In one implementation, the system information includes long-term ephemeris data, wherein changes to the long-term ephemeris data are transmitted via flags.

[0435] In one implementation, the UE receives position and velocity data included in the system information in a first cycle and a second cycle, respectively.

[0436] In one implementation, the UE searches for neighboring cells when the system information includes the parameter disable-s-IntraSearchP.

[0437] In one implementation, the system information includes neighbor cell selection information, and the UE prioritizes incoming cells over outgoing cells based on the neighbor cell selection information.

[0438] In one implementation, the system information also includes elliptical cell information, which includes the center, minor axis or minor semi-axis, and major axis or major semi-axis of the internal area of ​​the serving cell. Based on the elliptical cell information and the UE's location, the UE determines whether the UE is within the internal area of ​​the serving cell. When the UE is outside the internal area of ​​the serving cell and the signal measurement of a neighboring cell meets a threshold, the UE sends a measurement report or selects a neighboring cell as the serving cell.

[0439] Figure 21 A flowchart of another method 2100, which can be performed by a base station (BS) such as BS 102, according to an embodiment of this disclosure, is shown. Figure 21 The implementation of method 2100 shown is for illustrative purposes only. Figure 21 This disclosure is not intended to limit the scope to any particular implementation.

[0440] like Figure 21 As shown, method 2100 begins with operation 2102. In operation 2102, BS (e.g., as...) Figure 1 The system information generated (as shown in 101-103) includes: information corresponding to the location coordinates of the non-terrestrial network (NTN) gateway; information corresponding to the processing delay between the user equipment (UE) and the base station; and information corresponding to the location of the reference point.

[0441] In operation 2104, the BS sends system information.

[0442] In Operation 2106, the BS receives timing advance reports based on timing advance, where timing advance is based on the timing difference between the reference point location and the base station.

[0443] In one implementation, the BS autonomously receives a timing advance report when conditions are met or when random access is performed; periodically receives a timing advance report; or receives a timing advance report in response to a command from the BS.

[0444] In one implementation, the BS receives a timing advance report via a Radio Resource Control (RRC) message or via a Media Access Control (MAC) control element (CE).

[0445] In one implementation, the system information includes long-term ephemeris data, wherein changes to the long-term ephemeris data are transmitted via flags.

[0446] In one implementation, the BS transmits position and velocity data included in the system information in a first cycle and a second cycle, respectively.

[0447] In one implementation, the parameter disable-s-IntraSearchP, included in the system information, is used to search for neighboring cells.

[0448] In one implementation, the system information includes neighboring cell selection information that indicates that entering a cell takes precedence over leaving a cell.

[0449] In one implementation, the system information also includes elliptical cell information, which includes the center, minor axis or minor semi-axis, and major axis or major semi-axis of the internal area of ​​the serving cell; when an indication is received that the user equipment (UE) is outside the internal area of ​​the serving cell and when the signal measurement of a neighboring cell meets a threshold, a measurement report is received or a neighboring cell is selected as the serving cell.

[0450] The flowcharts above illustrate exemplary methods that can be implemented according to the principles of this disclosure, and various modifications can be made to the methods shown in the flowcharts herein. For example, although shown as a series of operations, the various operations in each diagram can overlap, occur in parallel, occur in different orders, or occur multiple times. In another example, certain operations can be omitted or replaced by other operations.

[0451] Figure 22 A base station according to an embodiment of the present disclosure is illustrated schematically.

[0452] refer to Figure 22 Base station 2200 may include processor 2210, transceiver 2220, and memory 2230. However, not all components shown are necessary. Base station 2200 may be composed of components such as processor 2210, transceiver 2220, and memory 2230. Figure 22 The components shown can be implemented with more or fewer components. Furthermore, according to another embodiment, the processor 2210, transceiver 2220, and memory 2230 can be implemented as a single chip.

[0453] In an exemplary embodiment, base station 2200 may be a gNodeB (gNB). In an exemplary embodiment, gNB 101, gNB 102 and gNB 103 described above may correspond to base station 2200.

[0454] The above-mentioned components will now be described in detail.

[0455] Processor 2210 may include one or more processors, or other processing devices that control the proposed functions, processes, and / or methods. Operation of base station 2200 may be implemented by processor 2210.

[0456] Transceiver 2220 may include an RF transmitter for up-converting and amplifying the transmitted signal, and an RF receiver for down-converting the received signal. However, according to another embodiment, transceiver 2220 may be implemented with more or fewer components than shown in the components.

[0457] Transceiver 2220 can be connected to processor 2210 and send and / or receive signals. Signals may include control information and data. Furthermore, transceiver 2220 can receive signals via a wireless channel and output signals to processor 2210. Transceiver 2220 can also transmit signals output from processor 2210 via a wireless channel.

[0458] Memory 2230 may store control information or data included in signals obtained by base station 2200. Memory 2230 may be connected to processor 2210 and store at least one instruction, protocol, or parameter for the proposed function, process, and / or method. Memory 2230 may include read-only memory (ROM) and / or random access memory (RAM) and / or hard disk and / or CD-ROM and / or DVD and / or other storage devices.

[0459] Figure 23 A user equipment (UE) according to an embodiment of this disclosure is shown.

[0460] refer to Figure 23 UE 2300 may include a processor 2310, a transceiver 2320, and a memory 2330. However, not all components shown are necessary. UE 2300 may be composed of components such as processor 2310, transceiver 2320, and memory 2330. Figure 23 The components shown can be implemented with more or fewer components. Furthermore, according to another embodiment, the processor 2310, transceiver 2320, and memory 2330 can be implemented as a single chip.

[0461] In an exemplary embodiment Figure 1 The UEs shown, 111-116, can correspond to UE 2300.

[0462] The above-mentioned components will now be described in detail.

[0463] Processor 2310 may include one or more processors, or other processing devices that control the proposed functions, processes, and / or methods. Operation of UE 2300 may be implemented by processor 2310.

[0464] Transceiver 2320 may include an RF transmitter for up-converting and amplifying the transmitted signal, and an RF receiver for down-converting the received signal. However, according to another embodiment, transceiver 2320 may be implemented with more or fewer components than shown in the components.

[0465] Transceiver 2320 can connect to processor 2310 and send and / or receive signals. Signals may include control information and data. Furthermore, transceiver 2320 can receive signals via a wireless channel and output signals to processor 2310. Transceiver 2320 can also transmit signals output from processor 2310 via a wireless channel.

[0466] Memory 2330 may store control information or data included in signals obtained by UE 2300. Memory 2330 may be connected to processor 2310 and store at least one instruction or protocol or parameter for the proposed function, process, and / or method. Memory 2330 may include read-only memory (ROM) and / or random access memory (RAM) and / or hard disk and / or CD-ROM and / or DVD and / or other storage devices.

[0467] Although this disclosure has been described with reference to exemplary embodiments, various changes and modifications can be suggested by those skilled in the art. This disclosure is intended to include such changes and modifications that fall within the scope of the appended claims. Nothing described in this application should be construed as implying that any particular element, operation, or function is an essential element that must be included within the scope of the claims. The scope of the patent subject matter is defined by the claims.

Claims

1. A user equipment (UE), comprising: transceiver; as well as The processor is operatively coupled to the transceiver and configured to: Receive configuration information from the base station (BS). Based on the UE location and the configuration information, the timing advance TA is determined, and If the difference between the TA and the previously reported TA exceeds a threshold, a TA report is sent to the BS via the Media Access Control-Control Element (MAC-CE).

2. The UE according to claim 1, wherein, The configuration information is received via the System Information Block (SIB); and The configuration information indicates the satellite ephemeris.

3. The UE according to claim 1, wherein, The threshold is received via a Radio Resource Control (RRC) message.

4. The UE according to claim 1, wherein; The TA is determined based on at least the sum of UE-specific values ​​and public values. The UE-specific value is determined based on the UE location and the satellite ephemeris included in the configuration information, and The public value is determined based on the configuration information.

5. A base station (BS), comprising: transceiver; as well as The processor is operatively coupled to the transceiver and configured to: Send configuration information to the user equipment (UE), and If the difference between the TA and the previously reported TA exceeds a threshold, a TA report is received from the UE via the Media Access Control-Control Element (MAC-CE). The TA is determined based on the UE location and the configuration information.

6. The BS according to claim 5, wherein, The configuration information is sent via the System Information Block (SIB), and The configuration information indicates the satellite ephemeris.

7. The BS according to claim 5, wherein, The threshold is sent via Radio Resource Control (RRC) messages.

8. The BS according to claim 5, wherein: The TA is determined based on at least the sum of UE-specific values ​​and public values. The UE-specific value is determined based on the UE location and the satellite ephemeris included in the configuration information, and The public value is determined based on the configuration information.

9. A method performed by a user equipment (UE), the method comprising: Receive configuration information from the base station (BS); The timing advance TA is determined based on the UE location and the configuration information; as well as If the difference between the TA and the previously reported TA exceeds a threshold, a TA report is sent to the BS via the Media Access Control-Control Element (MAC-CE).

10. The method according to claim 9, wherein, The configuration information is received via the System Information Block (SIB); and The configuration information indicates the satellite ephemeris.

11. The method according to claim 9, wherein, The threshold is received via a Radio Resource Control (RRC) message.

12. The method according to claim 9, wherein: The TA is determined based on at least the sum of UE-specific values ​​and public values. The UE-specific value is determined based on the UE location and the satellite ephemeris included in the configuration information, and The public value is determined based on the configuration information.

13. A method performed by a base station (BS), the method comprising: Send configuration information to the user equipment (UE); as well as If the difference between the TA and the previously reported TA exceeds a threshold, a TA report is received from the UE via the Media Access Control-Control Element (MAC-CE). The TA is determined based on the UE location and the configuration information.

14. The method according to claim 13, wherein, The configuration information is sent via the System Information Block (SIB), and The configuration information indicates the satellite ephemeris.

15. The method according to claim 13, wherein: The TA is determined based on at least the sum of UE-specific values ​​and public values. The UE-specific value is determined based on the UE location and the satellite ephemeris included in the configuration information, and The public value is determined based on the configuration information.

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