Cell type selection for non-terrestrial networks

Abstract

After a satellite handover for a permanently fixed Low Earth Orbit (LEO) cell, the User Equipment (UE) selects or reselects a target cell on a non-terrestrial network or restores a connection to the target cell. The target cell can be a serving cell or a non-serving cell. The UE determines the cell type of the target cell. The cell type can be an LEO cell type, a geostationary orbit (GEO) cell type, a mobile cell type, a fixed cell type, a temporarily fixed LEO cell type, or a permanently fixed LEO cell type. The UE selects, reselects, or restores a connection to the target cell based on the cell type.

Description

[Technical Field]

[0001] This patent application claims priority to U.S. Patent Application No. 17 / 475,140, ​​filed September 14, 2021, entitled “CELL TYPE SELECTION FOR NON-TERRESTRIAL NETWORKS,” which claims the benefit of U.S. Provisional Patent Application No. 63 / 078,872, filed September 15, 2020, entitled “CELL TYPE SELECTION FOR NON-TERRESTRIAL NETWORKS,” the disclosure of which is expressly incorporated herein by reference in its entirety.

[0002] The various forms of the content of this application generally relate to wireless communication, and more specifically, the various forms of the content of this application relate to techniques and apparatus for selecting between a first cell type (such as a low Earth orbit (LEO) cell type) and a second cell type (such as a geosynchronous orbit (GEO) cell type) in a non-terrestrial network (NTN). [Previous Technology]

[0003] Wireless communication systems are widely deployed to provide a variety of telecommunications services such as telephone, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiplexing access technologies that support communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiplexing access technologies include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier Frequency Division Multiple Access (SC-FDMA) systems, Time Division Synchronous Code Division Multiple Access (TD-SCDMA) systems, and Long Term Evolution (LTE). LTE / LTE-Enhanced is a collection of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile service standard issued by the 3rd Generation Partnership Project (3GPP).

[0004] A wireless communication network may include multiple base stations (BSs) capable of supporting communication for multiple user equipments (UEs). User equipments (UEs) may communicate with base stations (BSs) via downlinks and uplinks. A downlink (or forward link) refers to the communication link from the BS to the UE, and an uplink (or reverse link) refers to the communication link from the UE to the BS. As will be described in more detail, a BS may be referred to as a Node B, an evolved Node B (eNB), a gNB, an access point (AP), a radio headend, a transmit and receive point (TRP), a new radio (NR) BS, a 5G Node B, etc.

[0005] The multiplexing access technology described above has been adopted by various telecommunications standards to provide a common protocol that enables different user equipment to communicate at the city, country, regional, and even global levels. New Radio (NR) (which may also be referred to as 5G) is a collection of enhancements to the LTE mobile service standard issued by the 3rd Generation Partnership Project (3GPP). NR is designed to better integrate with other open standards by improving spectrum efficiency, reducing costs, improving service, utilizing new spectrum, and using Orthogonal Frequency Division Multiplexing (OFDM) with Cyclic Prefix (CP) on the downlink (DL) and CP-OFDM and / or SC-FDM (e.g., also known as Discrete Fourier Transform Extended OFDM (DFT-s-OFDM)) on the uplink (UL), and supporting beamforming, multiple-input multiple-output (MIMO) antenna technology and carrier aggregation to better support mobile broadband network access. [Summary of the Invention]

[0006] According to various embodiments of the present invention, a wireless communication method selects or reselects a target cell of a non-terrestrial network or restores a connection with the target cell. The target cell is a serving cell or a non-serving cell. The UE determines the cell type of the target cell. The cell type can be a low Earth orbit (LEO) cell type, a geostationary orbit (GEO) cell type, a mobile cell type, a fixed cell type, a temporarily fixed LEO cell type, or a permanently fixed LEO cell type. The UE also uses the cell type to select or reselect the target cell or restore the connection with the target cell.

[0007] In other embodiments of this case, an apparatus for wireless communication at a user equipment (UE) includes a processor and memory coupled to the processor. Instructions stored in the memory, when executed by the processor, can be operated to cause the apparatus to select or reselect a target cell on a non-terrestrial network or to restore a connection with the target cell. The target cell is a serving cell or a non-serving cell. The apparatus can determine the cell type of the target cell. The cell type can be a low Earth orbit (LEO) cell type, a geostationary orbit (GEO) cell type, a mobile cell type, a fixed cell type, a temporarily fixed LEO cell type, or a permanently fixed LEO cell type. The apparatus can also perform the selection or reselection of the target cell or the restoration of the connection with the target cell based on the cell type.

[0008] In other embodiments of this case, a user equipment (UE) for wireless communication includes: a unit for selecting or reselecting a target cell of a non-terrestrial network or re-establishing a connection with the target cell, the target cell being either a serving cell or a non-serving cell. The UE includes: a unit for determining the cell type of the target cell. The cell type may be a low Earth orbit (LEO) cell type, a geostationary orbit (GEO) cell type, a mobile cell type, a fixed cell type, a temporarily fixed LEO cell type, or a permanently fixed LEO cell type. The UE also includes: a unit for selecting or reselecting the target cell or establishing a connection with the target cell based on the cell type.

[0009] In other forms of the content of this case, a non-transitory computer-readable medium having code recorded thereon is disclosed. This code is executed by a user equipment (UE) and includes code for selecting or reselecting a target cell of a non-terrestrial network or re-establishing a connection with that target cell, which may be a serving cell or a non-serving cell. The UE includes code for determining the cell type of the target cell. The cell type includes low Earth orbit (LEO) cell type, geostationary orbit (GEO) cell type, mobile cell type, fixed cell type, temporarily fixed LEO cell type, or permanently fixed LEO cell type. The UE also includes code for performing the selection or reselection of the target cell or establishing the connection with the target cell based on the cell type.

[0010] Various types generally include methods, apparatus, systems, computer program products, non-transitory computer-readable media, user equipment, base stations, wireless communication devices and processing systems as generally described with reference to the accompanying drawings and description and shown by means of the accompanying drawings and description.

[0011] The features and technical advantages of the examples have been outlined rather broadly above in light of the contents of this application, so as to provide a better understanding of the specific embodiments described thereafter. Further features and advantages will be described. For the same purposes as the contents of this application, the disclosed concepts and specific examples can be readily used as a basis for modifying or designing other structures. Such equivalent constructions do not depart from the scope of the appended claims. The characteristics of the disclosed concepts (both their organization and operation) and their associated advantages will be better understood, together with the following description, when considered in conjunction with the accompanying drawings. Each of the drawings is provided for illustrative and descriptive purposes and is not intended to limit the scope of the claims.

Implementation Method

[0020] Wireless communication systems may include non-terrestrial networks with base stations that relay communications to user equipment (UEs) using satellites. In other scenarios, satellites may operate as base stations. For example, satellites may be low Earth orbit (LEO) satellites, geostationary orbit (GEO) satellites, high altitude platform stations (HAPS) or medium Earth orbit (MEO) satellites. Other cell types include mobile cells or stationary cells, as well as terrestrial network cells. UEs may have preferences or limitations regarding which cell type to select. The described techniques relate to UE cell selection for specific cell types in non-terrestrial networks.

[0021] First, the various forms of the present invention are described in the context of a wireless communication system. The various forms of the present invention are also shown and described with reference to program flow. Furthermore, the various forms of the present invention are shown and described with reference to apparatus diagrams, system diagrams, and flowcharts relating to cell type selection for non-terrestrial networks.

[0022] Figure 1 illustrates an example of a non-terrestrial wireless communication system 100 supporting cell type selection according to various embodiments of the present invention. The wireless communication system 100 includes a base station 105, a UE 115, a satellite 140, and a core network 130. In some instances, the wireless communication system 100 may be a Long Term Evolution (LTE) network, an improved LTE (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some cases, the wireless communication system 100 may support enhanced broadband communication, ultra-reliable (e.g., mission-critical) communication, low-latency communication, or communication with low-cost and low-complexity devices.

[0023] Base station 105 can wirelessly communicate with UE 115 via one or more base station antennas. Base station 105 may include or may be referred to by those skilled in the art as a base transceiver, radio base station, access point, radio transceiver, Node B, eNode B (eNB), next-generation Node B or giga-Node B (any of which may be referred to as gNB), home Node B, home eNode B, or some other suitable term. Wireless communication system 100 may include different types of base stations 105 (e.g., macro base stations or small cell base stations). The described UE 115 may be able to communicate with various types of base stations 105 and network devices including macro eNBs, small cell eNBs, gNBs, relay base stations, etc.

[0024] Each base station 105 may be associated with a specific geographic coverage area 110, in which communication with each UE 115 is supported. Each base station 105 may provide communication coverage to its respective geographic coverage area 110 via a communication link 125, and the communication link 125 between the base station 105 and the UE 115 may utilize one or more carriers. The communication link 125 shown in the wireless communication system 100 may include upstream transmission from the UE 115 to the base station 105 or downstream transmission from the base station 105 to the UE 115. Downstream transmission may also be referred to as downlink transmission or forward link transmission, while upstream transmission may also be referred to as uplink transmission or reverse link transmission.

[0025] The geographic coverage area 110 for base station 105 can be divided into sectors constituting a portion of the geographic coverage area 110, and each sector can be associated with a cell. For example, each base station 105 can provide communication coverage for macro cells, micro cells, hotspots, or other types of cells, or various combinations thereof. In some instances, base station 105 can be mobile, and thus provide communication coverage for mobile geographic coverage areas 110. In some instances, different geographic coverage areas 110 associated with different technologies can overlap, and overlapping geographic coverage areas 110 associated with different technologies can be supported by the same base station 105 or by different base stations 105. For example, wireless communication system 100 can include heterogeneous LTE / LTE-A / LTE-A Pro or NR networks, in which different types of base stations 105 provide coverage for various geographic coverage areas 110.

[0026] The term "cell" refers to a logical communication entity used for communication with base station 105 or a satellite beam (e.g., via a carrier wave), and can be associated with an identifier (e.g., a physical cell identifier (PCID) or a virtual cell identifier (VCID)) used to distinguish neighboring cells operating via the same or different carrier waves. A cell can be, for example, a mobile cell relative to a satellite beam, a temporarily fixed cell, or a permanently fixed cell. In some instances, a carrier wave can support multiple cells, and different cells can be configured according to different protocol types that can provide access to different types of devices (e.g., Machine Type Communication (MTC), Narrowband Internet of Things (NB-IoT), Enhanced Mobile Broadband (eMBB), etc.). In some cases, the term "cell" can refer to a portion of a geographic coverage area 110 (e.g., a sector) over which the logical entity operates.

[0027] UE 115 may be distributed throughout the wireless communication system 100, and each UE 115 may be stationary or mobile. UE 115 may also be referred to as a mobile device, wireless device, remote device, handheld device, or user equipment, or any other suitable term, wherein "device" may also be referred to as a unit, station, terminal, or client. UE 115 may also be a personal electronic device, such as a cellular phone, personal digital assistant (PDA), tablet computer, laptop computer, or personal computer. In some instances, UE 115 may also refer to a wireless area loop (WLL) station, Internet of Things (IoT) device, Internet of Things (IoE) device, or MTC device, which may be implemented in various items such as home appliances, vehicles, and meters.

[0028] Some UEs 115, such as MTC or IoT devices, can be low-cost or low-complexity devices, and can provide automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC can refer to data communication technologies that allow devices to communicate with each other or with base station 105 without human intervention. In some instances, M2M communication or MTC may include communication from devices integrating sensors or meters to measure or capture information and relay that information to a central server or application that can utilize the information or present it to personnel interacting with the application. Some UEs 115 may be designed to collect information or enable automated machine behavior. Examples of applications for MTC devices include: smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based billing.

[0029] Some UEs 115 can be configured to operate in a power-saving mode, such as half-duplex communication (e.g., a mode that supports unidirectional communication via transmission or reception but not simultaneous transmission and reception). In some instances, half-duplex communication can be performed at a reduced peak rate. Other power-saving techniques for UE 115 include entering a power-saving "deep sleep" mode when not engaged in active communication, or (e.g., operating on a limited bandwidth for narrowband communication). In some cases, UE 115 can be designed to support critical functions (e.g., mission-critical functions), and the wireless communication system 100 can be configured to provide highly reliable communication for these functions.

[0030] In some cases, UE 115 may also be able to communicate directly with other UE 115 (e.g., using peer-to-peer (P2P) or device-to-device (D2D) protocols). One or more of the UEs in a group of UEs 115 utilizing D2D communication may be within the geographic coverage area 110 of base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of base station 105, or may not be able to receive transmissions from base station 105 in other ways. In some cases, several groups of UEs 115 communicating via D2D communication may utilize a one-to-many (1:M) system, in which each UE 115 sends to each of the other UEs 115 in the group. In some cases, base station 105 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between UEs 115 without involving base station 105.

[0031] Base station 105 can communicate with and communicate with core network 130. For example, base station 105 can be connected to core network 130 via backhaul link 132 (e.g., via S1, N2, N3 or other interfaces). Base station 105 can communicate with each other directly (e.g., directly between base stations 105) or indirectly (e.g., via core network 130) via backhaul link 134 (e.g., via X2, Xn or other interfaces).

[0032] Core network 130 can provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. Core network 130 may be an Evolved Packet Core (EPC), which may include at least one Mobility Management Entity (MME), at least one Service Gateway (S-GW), and at least one Packet Data Network (PDN) Gateway (P-GW). The MME can manage non-access stratum (e.g., control plane) functions, such as mobility, authentication, and bearer management for UE 115 served by base station 105 associated with the EPC. User IP packets may be transmitted via the S-GW, which itself may be connected to the P-GW. The P-GW can provide IP address allocation and other functions. The P-GW may be connected to the IP services of a network service provider. The IP services of the service provider may include access to the Internet, intranet, IP Multimedia Subsystem (IMS), or packet switching (PS) streaming services.

[0033] At least some of the network devices (such as base station 105) may include sub-components such as access network entities, which may be instances of access node controllers (ANCs). Each access network entity may communicate with UE 115 via multiple other access network transport entities (which may be referred to as radio headends, smart radio headends, or transmit / receive points (TRPs)). In some configurations, the various functions of each access network entity or base station 105 may be distributed across various network devices (e.g., radio headends and access network controllers) or incorporated into a single network device (e.g., base station 105).

[0034] The wireless communication system 100 can operate using one or more frequency bands (typically in the range of 300 MHz to 300 GHz). Generally, the region from 300 MHz to 3 GHz is referred to as the ultra-high frequency (UHF) region or decimeter band because the wavelength range is approximately one decimeter to one meter in length. UHF waves may be blocked or deflected by buildings and environmental features. However, the waves can penetrate sufficiently into structures targeting macrocells to provide service to the UE 115 located indoors. Compared to transmission using smaller frequencies and longer wavelengths in the high frequency (HF) or ultra-high frequency (VHF) portions of the spectrum below 300 MHz, transmission of UHF waves can be associated with smaller antennas and shorter distances (e.g., less than 100 km).

[0035] The wireless communication system 100 can also operate in the ultra-high frequency (SHF) region using a frequency band from 3 GHz to 30 GHz (also known as the centimeter band). The SHF region includes frequency bands such as the 5 GHz industrial, scientific and medical (ISM) band, which can be used as appropriate by devices that can tolerate interference from other users.

[0036] The wireless communication system 100 can also operate in the extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz) (also known as the millimeter band). In some instances, the wireless communication system 100 can support millimeter-wave (mmWave) communication between the UE 115 and the base station 105, and the EHF antennas of the respective devices may be even smaller and more compact than UHF antennas. In some cases, this can facilitate the use of antenna arrays within the UE 115. However, propagation of EHF transmissions may suffer from even greater atmospheric attenuation and shorter distances than SHF or UHF transmissions. The disclosed techniques can be employed across transmissions using one or more different frequency regions, and the designated use of frequency bands across these frequency regions may vary due to national or regulatory factors.

[0037] In some cases, the wireless communication system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communication system 100 may employ licensed assisted access (LAA), unlicensed LTE (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz ISM band. When operating in an unlicensed radio frequency spectrum band, wireless devices such as base station 105 and UE 115 may employ a listen-before-talk (LBT) procedure to ensure that the frequency channel is idle before transmitting data. In some cases, operation in an unlicensed band may be based on a CA configuration that cooperates with CC operations in a licensed band (e.g., LAA). Operation in the unlicensed spectrum may include downstream transmissions, upstream transmissions, peer-to-peer transmissions, or combinations thereof. Duplexing in the unlicensed spectrum may be based on frequency division duplexing (FDD), time division duplexing (TDD), or a combination of both.

[0038] In some instances, base station 105 or UE 115 may be equipped with multiple antennas, which can be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. For example, wireless communication system 100 may use a transmission scheme between a transmitting device (e.g., base station 105) and a receiving device (e.g., UE 115), wherein the transmitting device is equipped with multiple antennas, and the receiving device is equipped with one or more antennas. MIMO communication can employ multipath signal propagation to increase spectral efficiency by transmitting or receiving multiple signals through different spatial layers, which can be called spatial multiplexing. For example, multiple signals can be transmitted by the transmitting device through different antennas or different combinations of antennas. Similarly, multiple signals can be received by the receiving device through different antennas or different combinations of antennas. Each of these multiple signals can be referred to as a separate spatial stream and can carry bits associated with the same data stream (e.g., the same coded characters) or different data streams. Different spatial layers can be associated with different antenna ports used for channel measurement and reporting. MIMO technology includes single-user MIMO (SU-MIMO) and multi-user MIMO (MU-MIMO), where multiple spatial streams are sent to the same receiving device under SU-MIMO, and multiple spatial streams are sent to multiple devices under MU-MIMO.

[0039] Beamforming (which may also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting or receiving device (e.g., base station 105 or UE 115) to shape or guide an antenna beam (e.g., a transmit beam or a receive beam) along a spatial path between the transmitting and receiving devices. Beamforming can be achieved by combining signals transmitted via antenna elements of an antenna array such that signals propagating in a specific direction relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to signals transmitted via antenna elements may include applying a certain amplitude and phase shift to the signals carried by each of the antenna elements associated with the transmitting or receiving device. The adjustments associated with each antenna element can be specified via a beamforming weight set associated with a specific direction (e.g., relative to the antenna array of the transmitting or receiving device, or relative to some other orientation).

[0040] In one example, base station 105 may use multiple antennas or antenna arrays to perform beamforming operations for directional communication with UE 115. For example, some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted multiple times by base station 105 in different directions, which may include transmitting signals according to different beamforming weight sets associated with different transmission directions. (e.g., by base station 105 or a receiving device such as UE 115) the beam direction for subsequent transmissions and / or receptions by base station 105 may be identified using transmissions in different beam directions. Some signals (such as data signals associated with a particular receiving device) may be transmitted by base station 105 in a single beam direction (e.g., the direction associated with a receiving device such as UE 115). In some instances, the beam direction associated with transmissions along a single beam direction may be determined at least in part based on signals transmitted in different beam directions. For example, UE 115 can receive one or more signals transmitted by base station 105 in different directions, and UE 115 can report to base station 105 an indication of the signal it received with the highest signal quality, or also report an acceptable signal quality. Although these techniques are described with reference to signals transmitted by base station 105 in one or more directions, UE 115 can employ similar techniques to transmit signals multiple times in different directions (e.g., to identify the beam direction for subsequent transmissions or receptions by UE 115), or to transmit signals in a single direction (e.g., to transmit data to a receiving device).

[0041] When a receiving device (e.g., UE 115, which may be an example of a millimeter-wave receiving device) receives various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from base station 105, it may attempt multiple receiving beams. For example, the receiving device may attempt multiple receiving directions by: receiving via different antenna subarrays, by processing signals received according to different antenna subarrays, by receiving according to different sets of receiving beamforming weights applied to signals received at multiple antenna elements of the antenna array, or by processing received signals according to different sets of receiving beamforming weights applied to signals received at multiple antenna elements of the antenna array, any of which may be referred to as "listening" according to different receiving beams or receiving directions. In some instances, the receiving device may use a single receiving beam to receive along a single beam direction (e.g., when receiving data signals). The single receiving beam can be aligned at least in part based on a beam direction determined by listening to different receiving beam directions (e.g., at least in part based on listening to multiple beam directions to determine the beam direction with the highest signal strength, the highest signal-to-noise ratio, or other acceptable signal quality).

[0042] In some cases, the antennas of base station 105 or UE 115 may be located within one or more antenna arrays that can support MIMO operation or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may coexist at antenna elements such as antenna towers. In some cases, the antennas or antenna arrays associated with base station 105 may be located in different geographical locations. Base station 105 may have an antenna array containing multiple rows and columns of antenna ports, which base station 105 can use to support beamforming for communications with UE 115. Similarly, UE 115 may have one or more antenna arrays that can support various MIMO or beamforming operations.

[0043] In some cases, the wireless communication system 100 may be a packet-based network operating according to a layered protocol stack. In the user plane, communication at the bearer or packet data convergence protocol (PDCP) layer may be IP-based. In some cases, the radio link control (RLC) layer may perform packet fragmentation and reassembly for communication via logical channels. The media access control (MAC) layer may perform prioritization and multiplexing of logical channels to transport channels. The MAC layer may also use Hybrid Automatic Repeat Request (HARQ) to provide retransmissions at the MAC layer to improve link efficiency. In the control plane, the radio resource control (RRC) protocol layer may provide the establishment, configuration, and maintenance of RRC connections between UE 115 and base station 105 or core network 130 supporting radio bearers for user plane data. At the physical (PHY) layer, transport channels may be mapped to physical channels.

[0044] In some cases, UE 115 and base station 105 may support retransmission of data to increase the likelihood of successfully receiving data. HARQ feedback is a technique to increase the likelihood of correctly receiving data via communication link 125. HARQ may include a combination of error correction (e.g., using cyclic redundancy check (CRC)), forward error correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQ can improve throughput at the MAC layer under poor radio conditions (e.g., signal-to-noise ratio conditions). In some cases, the radio device may support same-slot HARQ feedback, where the device can provide HARQ feedback in a specific slot for data received in a previous symbol within the slot. In other cases, the device can provide HARQ feedback in subsequent slots or according to some other time interval.

[0045] The time interval in LTE or NR can be expressed as a multiple of the basic time unit (e.g., it can refer to a sampling period of Ts = 1 / 30,720,000 seconds). The time interval of communication resources can be organized according to radio frames, each radio frame having a duration of 10 milliseconds (ms), where the frame period can be expressed as Tf = 307,200 Ts. The radio frame can be identified via a System Frame Number (SFN) ranging from 0 to 1023. Each frame can include 10 sub-frames numbered from 0 to 9, and each sub-frame can have a duration of 1 ms. (E.g., depending on the length of the cyclic prefix (CP) from the first code to each symbol period) The sub-frame can be further divided into 2 time slots, each time slot having a duration of 0.5 ms, and each time slot can contain 6 or 7 modulation symbol periods. Excluding the cyclic prefix, each symbol period can contain 2048 sampling periods. In some cases, a subframe can be the smallest scheduling unit of the wireless communication system 100, and may be referred to as a transmission time interval (TTI). In other cases, the smallest scheduling unit of the wireless communication system 100 may be shorter than a subframe, or may be dynamically selected (e.g., in a short pulse of a shortened TTI (sTTI), or in a component carrier selected using sTTI).

[0046] In some wireless communication systems, time slots can be further divided into multiple microtime slots containing one or more symbols. In some instances, the symbol of a microtime slot or microtime slot can be the smallest unit of scheduling. For example, each symbol can vary in duration depending on the subcarrier interval or the frequency band of operation. Furthermore, some wireless communication systems can implement time slot aggregation, in which multiple time slots or microtime slots are aggregated together for communication between UE 115 and base station 105.

[0047] The term "carrier" refers to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communications over communication link 125. For example, a carrier of communication link 125 may include a portion of a radio frequency spectrum band operating according to a physical layer channel for a given radio access technology. Each physical layer channel may carry user data, control information, or other signal transmissions. The carrier may be associated with a predefined frequency channel (e.g., an E-UTRA absolute radio frequency channel number (EARFCN)) and may be located according to a channel raster used for discovery by UE 115. The carrier may be downstream or upstream (e.g., in FDD mode), or configured to carry both downstream and upstream communications (e.g., in TDD mode). In some instances, the signal waveform transmitted via the carrier may consist of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as OFDM or DFT-s-OFDM).

[0048] The carrier organization structure can differ for different radio access technologies (e.g., LTE, LTE-A, LTE-A Pro, NR, etc.). For example, communication on a carrier can be organized according to TTIs or time slots, each of which may include user data and control information or signal transmissions for supporting the decoding of the user data. The carrier may also include dedicated capture signal transmissions (e.g., synchronization signals or system information, etc.) and control signal transmissions for coordinating operations on the carrier. In some instances (e.g., in a carrier aggregation configuration), the carrier may also have capture signal transmissions or control signal transmissions for coordinating operations on other carriers.

[0049] The physical channel can be multiplexed on the carrier using various technologies. For example, the physical control channel and the physical data channel can be multiplexed on the downstream carrier using time-division multiplexing (TDM), frequency-division multiplexing (FDM), or hybrid TDM-FDM technologies. In some instances, control information transmitted in the physical control channel can be distributed in a cascaded manner between different control areas (e.g., between a shared control area or common search space and one or more UE-specific control areas or UE-specific search spaces).

[0050] A carrier may be associated with a specific bandwidth of the radio frequency spectrum, and in some instances, the carrier bandwidth may be referred to as the carrier or the "system bandwidth" of the wireless communication system 100. For example, the carrier bandwidth may be one of a plurality of predetermined bandwidths of a carrier for a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz). In some instances, each serving UE 115 may be configured to operate over a portion or all of the carrier bandwidth. In other instances, some UEs 115 may be configured to operate using a narrowband protocol type associated with a predetermined portion or range within a carrier (e.g., a set of subcarriers or RBs) (e.g., "in-band" deployment of the narrowband protocol type).

[0051] In a system employing MCM technology, a resource element may include a symbol period (e.g., the duration of a modulation symbol) and a subcarrier, wherein the symbol period and the subcarrier interval are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme). Therefore, the more resource elements received by UE 115 and the higher the order of the modulation scheme, the higher the data rate that can be used for UE 115. In a MIMO system, radio communication resources may refer to a combination of radio frequency spectrum resources, time resources, and spatial resources (e.g., spatial layers), and the use of multiple spatial layers can further increase the data rate used for communication with UE 115.

[0052] The equipment of the wireless communication system 100 (e.g., base station 105 or UE 115) may have hardware settings to support communication over a specific carrier bandwidth, or may be configurable to support communication over one carrier bandwidth in a set of carrier bandwidths. In some instances, the wireless communication system 100 may include base station 105 and / or UE 115 that can support simultaneous communication via carriers associated with more than one different carrier bandwidth.

[0053] The wireless communication system 100 can support communication with the UE 115 on multiple cells or carriers, a feature that can be referred to as carrier aggregation (CA) or multi-carrier operation. Depending on the carrier aggregation configuration, the UE 115 can be configured to have multiple downstream CCs and one or more upstream CCs. Carrier aggregation can be used in conjunction with both FDD component carriers and TDD component carriers.

[0054] In some cases, the wireless communication system 100 may utilize enhanced component carrier (eCC). eCC may be characterized by one or more features including: wider carrier or frequency channel bandwidth, shorter symbol duration, shorter TTI duration, or modified control channel configuration. In some cases (e.g., when multiple serving cells have suboptimal or non-ideal backhaul links), eCC may be associated with carrier aggregation configurations or dual connectivity configurations. eCC may also be configured for use in unlicensed or shared spectrum (e.g., where more than one serving provider is permitted to use the spectrum). eCC characterized by wide carrier bandwidth may include one or more segments that may be utilized by a UE 115 that is unable to monitor the entire carrier bandwidth or is otherwise configured to use a limited carrier bandwidth (e.g., to save power).

[0055] In some cases, eCC may utilize a different symbol duration than other CCs, which may include the use of a reduced symbol duration compared to the symbol duration of other CCs. A shorter symbol duration may be associated with an increased spacing between adjacent subcarriers. Devices utilizing eCC (such as UE 115 or base station 105) may (e.g., depending on the frequency channel or carrier bandwidth of 20 MHz, 40 MHz, 60 MHz, 80 MHz, etc.) transmit broadband signals with a reduced symbol duration (e.g., 16.67 microseconds). The TTI in eCC may include one or more symbol periods. In some cases, the TTI duration (i.e., the number of symbol periods in the TTI) may be variable.

[0056] Wireless communication systems such as NR systems can utilize licensed, shared, and unlicensed spectrum bands, as well as any combination of other spectrum bands. The flexibility in eCC symbol duration and subcarrier spacing allows for the use of eCC across multiple spectrums. In some instances, NR shared spectrum can increase spectrum utilization and spectral efficiency, particularly through dynamic vertical (e.g., across the frequency domain) and horizontal (e.g., across the time domain) sharing of resources.

[0057] In some instances, the wireless communication system 100 may be or be associated with a terrestrial network. Some instances of a terrestrial network may include an NR system, for example, including base station 105 and UE 115. Within an NR system, upstream transmissions (e.g., CP-OFDM or DFT-S-OFDM waveforms) may arrive at base station 105 from UE 115 within an interval time (e.g., during the CP duration). For a subcarrier spacing of 120 kHz, the CP duration may be approximately 0.59 µs. Alternatively, the subcarrier spacing for mm-wave communications within the Ka band (such as downstream transmissions between approximately 20 GHz and 30 GHz) may be larger than that for upstream transmissions. For example, a subcarrier spacing greater than 120 kHz can improve communication reliability due to frequency errors caused by Doppler. In this example, a subcarrier spacing greater than 120 kHz may result in a CP duration of 0.25 µs.

[0058] In some instances, supplementally or alternatively, the wireless communication system 100 may be a non-terrestrial network or associated with it. For example, base station 105 may utilize satellite 140 to relay communications to UE 115. Due to the mobility of satellite 140 and the distance from satellite 140 to UE 115, communications may experience upstream timing errors (e.g., downstream timing tracking errors and / or variations in propagation delays). For example, satellite 140 may be a non-geostationary satellite that can operate from an orbit of 600 km around UE 115 and travel at a speed of approximately 7.6 km / s. Therefore, the round-trip time (e.g., update rate) between satellite 140 and UE 115 can vary by up to 50 µs per second.

[0059] For example, assuming the upstream timing is ideal at time t (e.g., no timing adjustment is applied to time t), after approximately 10 ms, the upstream timing error may be approximately 0.5 µs. Therefore, the round-trip time of satellite 140 may be approximately 30 ms, and the timing advance command calculated based on the upstream transmission at time t may be turned off by 1.5 µs when it reaches UE 115. To compensate for the upstream timing error, base station 105 (also referred to as the "gateway") may provide UE 115 with a timing command for the upstream transmission. UE 115 may receive the timing command and use the timing adjustment indicated in the timing command to send the upstream transmission to base station 105.

[0060] UE 115 may include a cell type selection module 150. For simplicity, only one UE 115 is shown as including a cell type selection module 150. The cell type selection module 150 can select or reselect a target cell from a non-terrestrial network or restore a connection to a target cell. The target cell may be a serving cell or a non-serving cell. The selection module 150 can also determine the cell type of the target cell. The selection module can also perform the selection or reselection of the target cell based on the cell type.

[0061] Figure 2 shows a block diagram of a design 200 for a base station 105 and a UE 115 (which may be one of the base stations in Figure 1 and one of the UEs). The base station 105 may be equipped with T antennas 234a to 234t, and the UE 115 may be equipped with R antennas 252a to 252r, wherein generally, T ≧ 1 and R ≧ 1.

[0062] At base station 105, transmit processor 220 can receive data for one or more UEs from data source 212, select one or more modulation and coding schemes (MCS) for each UE based at least in part on channel quality indicators (CQI) received from the UE, process (e.g., encode and modulate) the data for each UE based at least in part on the MCS selected for the UE, and provide data symbols for all UEs. Transmit processor 220 can also process system information (e.g., resource allocation information (SRPI) for semi-static applications, etc.) and control information (e.g., CQI requests, permission, upper-layer signaling, etc.), and provide management burden symbols and control symbols. Transmit processor 220 can also generate reference symbols (e.g., cell-specific reference signals (CRS)) and synchronization signals (e.g., primary synchronization signal (PSS) and secondary synchronization signal (SSS)) for reference signals. Where applicable, the transmit (TX) multiple-input multiple-output (MIMO) processor 230 can perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, management burden symbols, and / or reference symbols, and can provide T output symbol streams to T modulators (MODs) 232a to 232t. Each modulator 232 can process its own output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 can further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. The T downlink signals from modulators 232a to 232t can be transmitted separately via T antennas 234a to 234t. Depending on the various states described in more detail below, synchronization signals can be generated using position coding to convey additional information.

[0063] At UE 115, antennas 252a to 252r can receive downlink signals from base station 105 and / or other base stations, and can provide the received signals to demodulators (DEMODs) 254a to 254r respectively. Each demodulator 254 can adjust (e.g., filter, amplify, down-convert, and digitize) the received signal to obtain an input sample. Each demodulator 254 can further process the input sample (e.g., for OFDM, etc.) to obtain received symbols. MIMO detector 256 can obtain the received symbols from all R demodulators 254a to 254r, perform MIMO detection on the received symbols (if applicable), and provide the detected symbols. Receiver processor 258 can process (e.g., demodulate and decode) the detected symbols, provide the decoded data for UE 115 to data slot 260, and provide the decoded control information and system information to controller / processor 280. The channel processor can determine the Reference Received Power (RSRP), Received Signal Strength Indicator (RSSI), Reference Received Quality (RSRQ), Channel Quality Indicator (CQI), etc. In some configurations, one or more components in the UE 115 may be included within a housing.

[0064] On the uplink, at UE 115, transmit processor 264 can receive and process data from data source 262 and control information from controller / processor 280 (e.g., for reports including RSRP, RSSI, RSRQ, CQI, etc.). Transmit processor 264 can also generate reference symbols for one or more reference signals. Symbols from transmit processor 264 can be pre-encoded (if applicable) by TX MIMO processor 266, further processed by modulators 254a to 254r (e.g., for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to base station 105. At base station 105, uplink signals from UE 115 and other UEs can be received by antenna 234, processed by demodulator 254, detected by MIMO detector 236 (if applicable), and further processed by receive processor 238 to obtain decoded data and control information transmitted by UE 115. The receiver processor 238 can provide decoded data to the data slot 239 and decoded control information to the controller / processor 240. The base station 105 may include a communication unit 244 and transmit data to the core network 130 via the communication unit 244. The core network 130 may include a communication unit 294, a controller / processor 290, and memory 292.

[0065] The controller / processor 280 of UE 115 and / or any other component in FIG. 2 may execute one or more technologies associated with cell type selection, as described in more detail elsewhere herein. For example, the UE may be a smart UE or an NR UE capable of processing eMBB data and voice. The controller / processor 280 of UE 115 and / or any other component in FIG. 2 may execute or direct the operation of methods such as those of FIG. 6 and FIG. 7 and / or other procedures as described. Memory 242 and memory 282 may store data and code for base station 105 and UE 115, respectively. Scheduler 246 may schedule the UE for data transmission on downlink and / or uplink.

[0066] In some configurations, UE 115 may include units for selection, reselection or recovery, for decision-making, for completion, for acquisition, for receiving, for mapping, for prohibition, for tracking, for communication, and / or for reporting. Such units may include one or more components of UE 115 as described in conjunction with FIG. 2.

[0067] As indicated above, Figure 2 is provided merely as an example. Other examples may differ from those described with respect to Figure 2.

[0068] Figure 3 is a schematic diagram illustrating examples of a wireless communication system 300 supporting a cell type selection procedure for a non-terrestrial network according to various embodiments of the present invention. In some embodiments, the wireless communication system 300 may implement various embodiments of the wireless communication system 100 of Figure 1. The wireless communication system 300 may include a base station 105-a, a UE 115-a, and a satellite 140-a, which may be examples of the corresponding devices described with reference to Figure 1. For example, the wireless communication system 300 may be a non-terrestrial network, which may include a base station 105-a, a UE 115-a, and a satellite 140-a. The satellite 140-a may relay communications for the base station (e.g., base station 105-a) and the mobile terminal (e.g., UE 115-a). The base station 105-a may also be referred to as a gateway. The geographical area associated with the transmission beam of satellite 140-a can be called beam coverage area 330, and when UE 115-a is located within beam coverage area 330, UE 115-a can communicate with satellite 140-a.

[0069] Base station 105-a can perform communication procedures (e.g., Radio Resource Control (RRC) procedures, such as cell acquisition procedures, random access procedures, RRC connection procedures, or RRC configuration procedures) with UE 115-a. Base station 105-a can be configured with multiple antennas, which can be used for directional or beamformed transmission. As part of the communication procedures, base station 105-a can establish a bidirectional communication link 310 for communicating with UE 115-a. Supplementally or alternatively, as part of the communication procedures, base station 105-a can configure UE 115-a with configuration 315 (e.g., time and frequency resources, reference signal periodicity, or indication of symbols for time slots used to transmit reference signals) via RRC signal transmission. Although direct communication is shown, the present invention focuses primarily on when UE 115-a communicates with base station 105-a via satellite 140-a.

[0070] Satellite 140-a can generate satellite information (e.g., ephemeris information) associated with communication between satellite 140-a, UE 115-a, and base station 105-a. For example, satellite 140-a can determine the propagation delay associated with transmission between satellite 140-a, UE 115-a, and base station 105-a. In some cases, the propagation delay can be based on the distance d from satellite 140-a to point 305 (e.g., the center) of beam coverage area 330. In other cases, the propagation delay can be a factor of distance d, which can correspond to the round-trip distance between base station 105-a and satellite 140-a. Supplementally or alternatively, the propagation delay can be an estimated round-trip delay or round-trip time between UE 115-a and base station 105-a, which can be at least partially based on distance d and / or 2d. It should be noted that distance d may not reflect the precise distance from satellite 140-a to UE 115-a. For example, UE 115-a may be located at the edge of the beam coverage area 330, and its distance from satellite 140-a may differ from distance d. However, such distance differences may be insignificant compared to distance d. Therefore, distance d can be a sufficient representation of the distance from satellite 140-a to UE 115-a.

[0071] Satellite 140-a can transmit satellite information to base station 105-a and / or UE 115-a via wireless communication link 335, where base station 105-a and / or UE 115-a can be located within beam coverage area 330. In some cases, satellite 140-a can update satellite information and transmit it to base station 105-a and / or UE 115-a according to a pre-configured schedule (e.g., update rate). The pre-configured schedule can be based on the speed of satellite 140-a. For example, the speed of satellite 140-a may result in a maximum round-trip time variation rate of 50 µs per second. That is, for every second of movement of satellite 140-a, the round-trip time of communication between satellite 140-a and UE 115-a can vary by, for example, 50 µs. The round-trip time variation rate can also vary based on the motion of the satellite (e.g., orbit). In such cases, satellite 140-a can update satellite information multiple times per second. Alternatively or supplementally, for example, as part of configuration 315, base station 105-a may transmit satellite information to UE 115-a via bidirectional communication link 310. In some cases, base station 105-a may transmit satellite information to UE 115-a based on a pre-configured schedule (e.g., the update rate of satellite 140-a).

[0072] Satellite information may also include the velocity of satellite 140-a. In some cases, the velocity of satellite 140-a may be defined or associated with the following formula: , where α is the angle between the velocity vector v and the range vector d. UE 115-a may use the velocity of satellite 140-a to determine the round-trip time variation rate. In some cases, UE 115-a may use the velocity of satellite 140-a to determine the round-trip time variation rate, at least in part, based on the positioning of UE 115-a relative to point 305 of beam coverage area 330. In some instances, using the velocity of satellite 140-a, the round-trip time variation rate may be defined via the following formula: , where α is the angle between the velocity vector v and the range vector d, and c is the speed of light. Accordingly, if the upstream transmission is scheduled to be sent at time t0 with a timing adjustment ta, the actual transmission time of UE 115-a may be t0+ta. For a subsequent upstream transmission scheduled to be sent at time ta+∆t without a new timing adjustment provided by base station 105-a, the actual transmission time of UE 115-a can be ta+∆t×().

[0073] When UE 115-a is in Discontinuous Receive (DRX) mode and in RRC_IDLE or RRC_CONNECTED state, base station 105-a may transmit downlink control information in certain time and frequency resources (e.g., fixed symbols). Between these time and frequency resources, UE 115-a may enter a low-power state (also known as "sleep mode") to reduce power consumption and increase battery life. In RRC_IDLE or RRC_CONNECTED state, UE 115-a may wake up once every few symbols to receive downstream transmissions from base station 105-a and / or satellite 140-a. The gaps allocated before and after reference signal transmissions can benefit base station 105-a by reducing or eliminating interference between UE 115-a transmissions and transmissions from another adjacent UE.

[0074] Figure 4 is a schematic diagram illustrating an alternative network configuration of a wireless communication system 400 supporting cell type selection for non-terrestrial networks, according to various embodiments of the present invention. In this configuration, base station 105-b is located on satellite 140-b. Base station 105-b communicates with core network 130-b via wireless communication link 335. UE 115-b communicates with non-terrestrial base station 105-b via wireless communication link 335.

[0075] Figure 5 is a schematic diagram illustrating the network configuration of a wireless communication system 500 supporting cell type selection for non-terrestrial networks according to various embodiments of the present invention. In Figure 5, two different satellites 140-b and 140-c are illustrated. For ease of explanation, base stations and core networks are not illustrated. The first satellite 140-b may be a GEO satellite with a first beam coverage area 330-b. The second satellite 140-c may be a LEO satellite with a second beam coverage area 330-c. The UE 115-b communicates with satellites 140-b and 140-c via wireless communication links 335-b and 335-c, respectively. In some embodiments, the UE 115-b may have a preference for the cell type it wants to select (e.g., LEO or GEO). In other embodiments, the UE 115-b may have restrictions regarding the cell types it can select. For example, certain cell types may have different requirements. The various aspects of this case relate to how a UE selects a cell type (e.g., LEO vs. GEO, or moving vs. stationary cells) during a cell selection or cell reselection procedure in a non-terrestrial network, or how to restore a connection when operating in a permanently stationary LEO cell type.

[0076] As shown in Figure 5, in a non-terrestrial network (NTN), the UE can be covered by multiple cells with different cell types. Although Figure 5 describes LEO and GEO cell types, other cell types also exist. For example, cell type selection can be between terrestrial network cell types and non-terrestrial network cell types. The UE can also consider other types of satellite cell types, such as High Altitude Platform Station (HAPS) cell types and Medium Earth Orbit (MEO) cell types. Furthermore, the UE can select between mobile cells and fixed cells, or between temporarily fixed cells and permanently fixed cells.

[0077] In order to select between different cell types, the UE should be able to distinguish one cell from another. LEO satellites and GEO satellites can operate in the same frequency band. Therefore, by acquiring a synchronization signal block (SSB), the UE may not be able to distinguish whether the cell type is an LEO cell or a GEO cell.

[0078] Various forms of this invention relate to techniques for detecting cell types during cell selection or cell reselection procedures. In one configuration, to detect cell types (e.g., LEO cells and GEO cells), LEO cells and GEO cells are configured to use different demodulation reference signals (DMRS) to decode the main information block (MIB). In another configuration, each of the LEO and GEO cells is configured to use different scrambling codes for the physical broadcast channel (PBCH). In yet another configuration, the physical cell ID (PCID) or system information block (SIB) (e.g., system information block, type 1 (SIB1)) is defined as LEO or GEO specific. In some cases, the UE can be configured to select only specific cell types, such as LEO cells or GEO cells. Supplementally or alternatively, the UE can be configured with different priorities for different cell types. For example, the UE can prioritize LEO cells over GEO cells, or the UE can prioritize moving cells over stationary cells. Therefore, it may be desirable for the UE to distinguish between cell types.

[0079] Due to the requirements of operation in specific cell types, cell type priority may be desired. For example, since LEO satellites are at lower altitudes than GEO satellites, the UE should track the time and frequency compensation parameters (e.g., timing advance (TA) and Doppler shift parameters) of LEO satellites more closely. More frequent tracking is appropriate because LEO satellites are more likely to exhibit Doppler shift and timing advance errors.

[0080] Examples of UE requirements for operation in LEO or GEO cells may include, for example, tracking for frequency compensation and uplink (UL) timing pre-compensation to address the Doppler effect. Additionally, UE support for large cell sizes may be specified, for example, in the case of GEO cells. Therefore, UE support for new physical random access channels (PRACH) formats for GEO cells may be specified. Otherwise, the UE should select LEO cells. Other UE requirements include, for example, support for a larger number of Hybrid Automatic Repeat Request (HARQ) procedures to maintain throughput or enabling and disabling HARQ procedures or different Quality of Service (QoS) requirements (e.g., support for different Service Data Adaptation Protocol (SDAP) / Packet Data Convergence Protocol (PDCP) configurations, larger PDCP drop timers, and / or larger sequence number (SN) lengths).

[0081] Depending on the specifics of this case, the cell may broadcast information regarding the UE's requirements for operation in a specific cell type (such as a LEO cell or a GEO cell). For example, if the UE wants to operate in a LEO cell, the UE should support timing advance and Doppler compensation. If the UE does not meet these requirements, the UE should select another cell type.

[0082] Alternatively, a UE profile can be defined to indicate different requirements for operation in different cell types. In this example, the base station does not broadcast a list of requirements. In fact, the base station can broadcast an index representing a set of requirements. When reading the index, the UE identifies the requirements for operation in the cell. The UE can be pre-configured or provided with details of the requirement profile (e.g., configuration). In this option, a separate indication of the cell type (e.g., whether the cell is LEO or GEO) may not be required.

[0083] According to various embodiments of the present invention, the UE can determine the operation requirements for a specific cell type (e.g., LEO or GEO cell) by reading the cell's SIB1 (or another SIB). In other embodiments, the UE can be configured with information indicating the operation requirements based on per PCID or per frequency. For example, the PCID and / or frequency can be mapped to a profile ID or index. In this example, the UE can determine whether it can meet the requirements based on the PCID. If the UE cannot meet the requirements, the UE can disable the cell and exclude it from the candidate for cell reselection. Although SIB1 broadcasting is described, other SIBs (such as non-terrestrial network-specific SIBs) can carry operation requirements or profile IDs.

[0084] Depending on the specifics of this case, the UE may also report its capabilities regarding the requirements for operation in a particular cell type. Based on the reported capabilities, the network may redirect the UE to the appropriate cell. For example, if the UE selects a GEO cell but reports that it does not meet the operational requirements for a GEO cell, the base station may redirect the UE to an LEO cell (assuming the UE has capabilities that match the operational requirements for LEO cells).

[0085] In other formats, for each frequency within and / or between neighboring cells (e.g., in a list of neighboring cells) or within a frequency list, a cell can broadcast a request for operation in a specific cell type (or supported profile). Therefore, the UE is aware not only of the service cell's request but also of the operation request for each neighboring cell, thereby facilitating cell reselection. The broadcast may include a mapping of cell IDs (e.g., PCIDs) or frequencies to UE requests for operation in a specific cell. This mapping can assist the UE in cell reselection. The base station may broadcast this mapping in an SIB message.

[0086] In addition to requirements for operation in LEO and GEO cells, the base station can also indicate whether the cell type is a mobile cell, a temporarily fixed cell, or a permanently fixed cell. In some cases, this indication can be implicitly obtained from the beam pattern configuration in the SIB message.

[0087] LEO-fixed cells can further differentiate into LEO-temporarily fixed cells or LEO-permanently fixed cells. For permanently fixed cells, in the RRC_connected state, the UE may experience service interruption during satellite handover. That is, the cell ID, System Information Block (SIB) configuration, and Radio Resource Control (RRC) configuration remain unchanged, while the cell's operation switches from one satellite to another. In this case, the RRC connection may be suspended during the interruption and resumed afterward. This may be a special case of satellite handover, while the gateway and / or base station serving the UE remains unchanged. In the RRC_idle state, the UE may experience signal interruption or loss during satellite handover. In this case, paging monitoring may be suspended during the interruption and resumed afterward.

[0088] According to the various forms of this case, satellite communication gaps can be configured in the UE. During this gap period, when a cell switches from a previous satellite to a new satellite, the UE suspends uplink / downlink (UL / DL) transmission or paging monitoring. After the gap period, the UE resumes communication with the new satellite. If the UE does not support this operating specification, the UE may not select a cell with a permanently fixed LEO.

[0089] Cell stop times can be broadcast in the SIB. Cell stop times broadcast in the SIB can be used as the starting point for an interruption. They can also indicate the duration of the interruption.

[0090] Figure 6 is a dialing flowchart illustrating cell type selection for various non-terrestrial networks according to the content of this case. At time t1, UE 610 receives an instruction from satellite 620 of the first cell type. In this example, the first cell type is an LEO cell type. UE 610 also receives a request for operation in the LEO cell type. At time t2, UE 610 receives an instruction from satellite 630 of the second cell type. In this example, the second cell type is a GEO cell type. UE 610 also receives a request for operation in the GEO cell type.

[0091] At time t3, UE 610 determines the cell type to select. In this example, the UE is configured with a priority list, where LEO is the first priority and GEO is the second priority. UE 610 also checks the operational requirements to confirm that the UE has the capability to support the operational requirements. At time t4, UE 610 selects satellite 620 of the first cell type (e.g., LEO).

[0092] As indicated above, Figure 3-6 is provided as an example. Other examples may differ from those described with respect to Figure 3-5.

[0093] Figure 7 is a flowchart illustrating a method 700 performed by a user equipment (UE) supporting a cell type selection procedure for non-terrestrial networks, for example, according to various aspects of the present invention. The operation of method 700 may be implemented by a network device or component thereof as described (e.g., UE 115).

[0094] As shown in FIG7, in some states, method 700 may include: selecting or reselecting a target cell of a non-terrestrial network or restoring a connection with a target cell (block 702). For example, user equipment (UE) (e.g., using antenna 252, DEMOD / MOD 254, MIMO detector 256, TX MIMO processor 266, receiver processor 258, transmitter processor 264, controller / processor 280, and / or memory 282) may select or reselect a target cell or restore a connection. In some states, the target cell is a serving cell or a non-serving cell.

[0095] Method 700 may include: determining the cell type of the target cell (block 704). For example, the UE (e.g., using antenna 252, DEMOD / MOD 254, MIMO detector 256, receiver processor 258, controller / processor 280, and / or memory 282) may determine the cell type of the target cell. The cell type may be a low Earth orbit (LEO) cell type, a geostationary orbit (GEO) cell type, a mobile cell type, a fixed cell type, a temporarily fixed LEO cell type, or a permanently fixed LEO cell type. For example, the UE may determine the cell type based on the demodulation reference signal (DMRS) used for decoding the main information block (MIB), the scrambling code used for the physical broadcast channel (PBCH), and / or the physical cell identity (PCID). In other cases, the UE may determine the cell type based on the beam pattern configuration within the system information block (SIB) message.

[0096] Method 700 may also include: selecting or reselecting a target cell based on cell type (block 706). For example, the UE (e.g., using antenna 252, DEMOD / MOD 254, MIMO detector 256, TX MIMO processor 266, receiver processor 258, transmitter processor 264, controller / processor 280, and / or memory 282) can select or reselect a target cell. In some states, the selection, reselection, or connection is performed only for one cell type. In other states, the selection, reselection, or connection is performed according to a priority set, each priority corresponding to a different cell type. Examples of various states

[0097] Sample 1: A method for wireless communication by a user equipment (UE), comprising: selecting or reselecting a target cell of a non-terrestrial network or restoring a connection with the target cell, the target cell including a serving cell or a non-serving cell; determining the cell type of the target cell, the cell type including a low Earth orbit (LEO) cell type, a geostationary orbit (GEO) cell type, a mobile cell type, a fixed cell type, a temporarily fixed LEO cell type, or a permanently fixed LEO cell type; and performing the selection or reselection of the target cell or restoring the connection with the target cell based on the cell type.

[0098] State 2: According to the method of State 1, wherein the cell type is determined based on the demodulation reference signal (DMRS) used for decoding the main information block (MIB), the scrambling code used for the physical broadcast channel (PBCH), and / or the physical cell identity (PCID).

[0099] State 3: The method according to state 1 or state 2 also includes: performing the selection or reselection or connection only for one cell type.

[0100] State 4: The method according to any one of the preceding states also includes: performing the selection or the reselection or the connection according to a priority set, each of the priority sets corresponding to one of a plurality of different cell types.

[0101] State 5: The method according to any one of the foregoing states also includes: obtaining requirements for operation in the cell type, the decision on the cell type being based on such requirements.

[0102] State 6: According to the method of State 5, wherein the requirements are obtained via broadcast information.

[0103] State 7: According to the method of State 6, wherein the broadcast information includes a profile identifier corresponding to the requirements for operation in that cell type.

[0104] State 8: According to the method of State 6, wherein the broadcast information includes a physical cell identity (PCID) mapped to a profile identifier and / or frequency.

[0105] State 9: According to the method of State 6, wherein the broadcast information is obtained via a non-terrestrial network specific system information block (SIB) message.

[0106] State 10: According to the method of State 6, wherein the requirements are associated with a plurality of neighboring cells in the neighboring cell list or frequencies in the frequency inter-list.

[0107] State 11: According to the method of State 6, wherein the broadcast information includes a mapping of cell ID or cell frequency to such requirements for operation in that cell type.

[0108] State 12: The method according to State 5 also includes: prohibiting the target cell in response to the inability to meet the requirements for manipulating the cell type.

[0109] State 13: According to the method of State 5, wherein the requirements for operation in this cell type are based on frequency compensation for solving the Doppler effect, tracking of uplink timing pre-compensation, support for large cell size, support for the number of Hybrid Automatic Repeat Request (HARQ) procedures exceeding a first threshold, the ability to enable and disable HARQ procedures, or support for Quality of Service (QoS) specifications.

[0110] State 14: According to the method of State 13, wherein the QoS specifications include: support for a specific Service Data Adaptation Protocol (SDAP) configuration, support for a specific Packet Data Convergence Protocol (PDCP) configuration, support for a PDCP drop timer exceeding a second threshold, and / or support for a sequence number (SN) having a length greater than a third threshold.

[0111] State 15: The method according to any one of the foregoing states also includes: reporting the UE capability related to the requirements for operation in the cell type.

[0112] State 16: The method according to State 15 also includes: obtaining instructions for redirecting to different target cells based on the UE capabilities.

[0113] State 17: The method according to any one of the preceding states, wherein the cell type is determined based on the beam pattern configuration within the System Information Block (SIB) message.

[0114] State 18: The method according to any one of the preceding states also includes: obtaining a satellite communication gap configuration in response to the cell type being the permanently fixed LEO cell type.

[0115] State 19: The method according to any one of the foregoing states also includes: responding to the fact that the UE cannot be configured with a satellite communication gap to disable the permanently fixed LEO cell type.

[0116] State 20: The method according to any one of the preceding states, wherein the permanently fixed LEO cell type includes cells served by a first satellite and subsequently by a second satellite after a satellite switchover, wherein a satellite communication gap occurs during the satellite switchover.

[0117] State 21: According to the method of State 20, the cell identifier (ID) remains unchanged after the satellite is switched.

[0118] State 22: According to the method of State 20, the System Information Block (SIB) configuration and Radio Resource Control (RRC) configuration remain unchanged after the satellite handover and communication is restored after the satellite communication gap.

[0119] State 23: The method according to state 20 also includes: obtaining an indication of the duration of the satellite communication gap.

[0120] State 24: The method according to State 20 also includes: obtaining a system information block (SIB), the SIB including the cell stop time as the starting point of the satellite communication gap.

[0121] Sample 25: An apparatus for wireless communication by a user equipment (UE), comprising: at least one processor, memory coupled to the at least one processor; and instructions stored in the memory and operable when executed by the at least one processor to cause the apparatus to perform the following operations: select or reselect a target cell of a non-terrestrial network or restore a connection with the target cell, the target cell including a serving cell or a non-serving cell; determine the cell type of the target cell, the cell type including a low Earth orbit (LEO) cell type, a geostationary orbit (GEO) cell type, a mobile cell type, a fixed cell type, a temporarily fixed LEO cell type, or a permanently fixed LEO cell type; and perform the selection or reselection of the target cell or the restoration of the connection with the target cell based on the cell type.

[0122] State 26: The apparatus according to state 25, wherein the at least one processor causes the apparatus to perform the following operation: determine the cell type based on the demodulation reference signal (DMRS) used for decoding the main information block (MIB), the scrambling code used for the physical broadcast channel (PBCH), and / or the physical cell identity (PCID).

[0123] State 27: The apparatus according to State 25 or State 26, wherein the permanently fixed LEO cell type includes cells served by a first satellite and subsequently by a second satellite after a satellite switchover, wherein a satellite communication gap occurs during the satellite switchover.

[0124] State 28: The apparatus according to any one of states 25-27, wherein the cell identifier (ID) remains unchanged after the satellite switch.

[0125] Format 29: The apparatus according to any one of Formats 25-28, wherein the at least one processor is also configured to: obtain an indication of the duration of the satellite communication gap.

[0126] Format 30: A user equipment including a unit for performing operations according to one or more formats 1-24.

[0127] Format 31: A user device including a transceiver, memory and at least one processor configured to perform the operation of one or more formats of formats 1-24.

[0128] Format 32: A computer-readable medium for wireless communication by a user equipment (UE), including code executable by the UE to perform one or more of the formats 1-24.

[0129] The foregoing disclosure provides explanation and description, but is not intended to be exhaustive or to limit the various forms to the precise forms disclosed. Modifications and changes may be made based on the foregoing disclosure, or may be derived from the implementation of the various forms.

[0130] As used, the term "component" is intended to be interpreted broadly as hardware, firmware, and / or a combination of hardware and software. As used, a processor is implemented in a combination of hardware, firmware, and / or hardware and software.

[0131] Some states are described in conjunction with thresholds. As used, depending on the context, satisfying a threshold can refer to a value that is greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, etc.

[0132] It will be apparent that the described systems and / or methods can be implemented in different forms, including hardware, firmware, and / or combinations of hardware and software. The actual, specialized control hardware or software code used to implement these systems and / or methods is not a limitation on the variety. Therefore, the operation and behavior of the systems and / or methods are described without reference to specific software code—it is to be understood that the software and hardware can be designed to implement the systems and / or methods at least in part based on the description.

[0133] Even if a particular combination of features is described in the claims and / or disclosed in the specification, such combinations are not intended to limit the disclosure of the individual aspects. In fact, many of these features may be combined in ways not explicitly described in the claims and / or disclosed in the specification. Although each dependent claim listed below may depend directly on only one claim, the disclosure of the individual aspects includes each dependent claim combined with other claims in each of the claim sets. The phrase “at least one of” in the list of entries refers to any combination of these entries, including single members. For example, “at least one of a, b, or c” is intended to cover: a, b, c, ab, ac, bc, and abc, and any combination of the same elements with multiples (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc or any other ordering of a, b, and c).

[0134] Unless explicitly stated otherwise, the elements, actions, or instructions used should not be construed as decisive or essential. Furthermore, as used, the articles "a" and "an" are intended to include one or more entries and can be used interchangeably with "one or more." Furthermore, as used, the terms "set" and "group" are intended to include one or more entries (e.g., related entries, unrelated entries, combinations of related and unrelated entries, etc.) and can be used interchangeably with "one or more." Where only one entry is intended, the phrase "only one" or similar language is used. Additionally, as used, the terms "has," "have," and "having" are intended to be open-ended terms. Further, unless explicitly stated otherwise, the phrase "based on" is intended to mean "at least partially based on." [Simplified Explanation of the Diagram]

[0012] To gain a more detailed understanding of the features of this application, reference can be made to various embodiments, some of which are shown in the accompanying drawings. However, it should be noted that the drawings only show certain embodiments of this application and are therefore not intended to limit its scope, as the specification may acknowledge other equally valid embodiments. The same element symbols in different drawings may identify the same or similar elements.

[0013] Figure 1 is a block diagram conceptually illustrating examples of various types of wireless communication networks according to the contents of this case.

[0014] Figure 2 is a block diagram conceptually illustrating an example of communication between a base station and a user equipment (UE) in a wireless communication network of various forms according to the contents of this case.

[0015] Figure 3 is a schematic diagram illustrating an example of a wireless communication system supporting cell type selection for non-terrestrial networks according to various forms of the present invention.

[0016] Figure 4 is a schematic diagram illustrating alternative network configurations for wireless communication systems supporting cell type selection for non-terrestrial networks, according to various aspects of the present invention.

[0017] Figure 5 is a schematic diagram showing the network configuration of a wireless communication system supporting cell type selection for non-terrestrial networks according to various forms of the present invention.

[0018] Figure 6 is a call flowchart showing the cell type selection of various non-terrestrial networks according to the contents of this case.

[0019] Figure 7 is a flowchart illustrating various forms of an example program executed by a user equipment (UE) according to the contents of this case. [Biomaterial Storage]

[0136] Domestic storage information (please note in order of storage institution, date, and number): None. International storage information (please note in order of storage country, institution, date, and number): None.

Claims

1. A method for wireless communication at a user equipment (UE), comprising the steps of: re-establishing a connection with a target cell of a non-terrestrial network; completing the connection with the target cell based on a cell type, the cell type including a permanently fixed LEO cell type, wherein the permanently fixed LEO cell type is associated with a cell served by a first satellite, and subsequently associated with a cell served by a second satellite after a satellite handover, wherein a satellite communication gap occurs during the satellite handover, the first satellite and the second satellite having the same cell identity.

2. According to the method of request item 1, wherein the first satellite and the second satellite have the same System Information Block (SIB) configuration.

3. The method according to request item 1, wherein the UE uses a radio resource control (RRC) configuration for communication and resumes communication after the satellite communication gap, and the RRC configuration remains unchanged after the satellite handover.

4. The method according to claim 1 also includes the following steps: obtaining an indication of the duration of the satellite communication gap; and suspending communication during the satellite communication gap based on the duration.

5. The method according to claim 1, wherein the satellite communication gap includes a suspended radio resource control (RRC) connection.

6. The method according to claim 1 further includes obtaining a satellite communication gap configuration because the cell type is the permanently fixed LEO cell type.

7. The method according to claim 1 further includes obtaining a System Information Block (SIB) including a time that is a starting point of the satellite communication gap.

8. The method according to claim 1 further includes obtaining a System Information Block (SIB), the SIB including a time that is an end point of the satellite communication gap.

9. An apparatus for wireless communication, comprising: At least one processor; At least one memory element coupled to the at least one processor; The device contains and is operable instructions stored in the at least one memory, which, when executed by the at least one processor, cause the device to perform the following actions: restore connection to a target cell on a non-terrestrial network; and establish the connection with the target cell based on a cell type, the cell type including a permanently fixed LEO cell type, wherein the permanently fixed LEO cell type is associated with a cell served by a first satellite, and subsequently associated with a cell served by a second satellite after a satellite handover, wherein a satellite communication gap occurs during the satellite handover, and the first satellite and the second satellite have the same cell identity.

10. The apparatus according to claim 9, wherein at least one of the following is true: the first satellite and the second satellite have the same System Information Block (SIB) configuration; or the satellite communication gap includes a Suspension Radio Resource Control (RRC) connection.

11. The apparatus according to claim 9, wherein the processor causes the apparatus to use a Radio Resource Control (RRC) configuration for communication and to resume communication after the satellite communication gap, the RRC configuration remaining unchanged after the satellite handover.

12. The apparatus according to claim 9, wherein the processor causes the apparatus to obtain an indication of the duration of the satellite communication gap, and to suspend communication during the satellite communication gap based on the duration.

13. The apparatus according to claim 9, wherein the processor causes the apparatus to acquire a satellite communication gap configuration due to the cell type being the permanently fixed LEO cell type.

14. The apparatus according to claim 9, wherein the processor causes the apparatus to obtain a System Information Block (SIB), the SIB including a time that is a start point of the satellite communication gap.

15. The apparatus according to claim 9, wherein the processor causes the apparatus to obtain a System Information Block (SIB), the SIB including a time that is an end point of the satellite communication gap.

16. A user equipment (UE), comprising: One transceiver; At least one memory, including instructions; and at least one processor configured to execute the instructions to cause the UE to: restore a connection to a target cell on a non-terrestrial network via the transceiver; and establish the connection to the target cell based on a cell type, the cell type including a permanently fixed LEO cell type, wherein the permanently fixed LEO cell type is associated with a cell served by a first satellite, and subsequently associated with a cell served by a second satellite after a satellite handover, wherein a satellite communication gap occurs during the satellite handover, and the first satellite and the second satellite have the same cell identity.

17. The UE according to request item 16, wherein the processor causes the UE to use a Radio Resource Control (RRC) configuration for communication and resumes communication after the satellite communication gap, the RRC configuration remaining unchanged after the satellite handover.

18. The UE according to request item 16, wherein the first satellite and the second satellite have the same System Information Block (SIB) configuration.

19. The method of claim 16, wherein the processor causes the UE to obtain an indication of the duration of the satellite communication gap and suspend communication during the satellite communication gap based on the duration.

20. The UE according to request item 16, wherein the processor obtains a System Information Block (SIB) including a time that is a start point of the satellite communication gap.

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