Paging functionality in non-terrestrial wireless network (NTN)

Abstract

The disclosure relates to paging functionality in a non-terrestrial wireless network (NTN). Mechanisms are provided for a user equipment (UE) to receive a paging alert signal associated with a paging occasion. The UE may receive a synchronization signal from a wireless network, and also receive a paging alert signal (PAS). The PAS may indicate a paging occasion associated with the PAS. The UE may also receive information associated with the paging occasion associated with the PAS, the information associated with the paging occasion being carried by a physical downlink control channel (PDCCH), and also receive a paging message carried by a physical downlink shared channel (PDSCH).

Description

[0001] Related Patent Applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 604,649, filed on November 30, 2023, the entire content of which is incorporated herein by reference. Background Art Technical Field

[0003] The described aspects generally relate to non-terrestrial wireless networks (NTN), including paging functions for user equipment (UE) in NTN.

[0004] Related Technologies

[0005] A wireless communication system may include a fifth-generation (5G) system, a new radio (NR) system, a long-term evolution (LTE) system, a non-terrestrial wireless network (NTN), a combination thereof, or some other wireless system. Additionally, a wireless communication system may support a wide range of use cases, such as enhanced mobile broadband (eMBB), massive machine type communication (mMTC), ultra-reliable and low-latency communication (URLLC), enhanced vehicle-to-everything communication (eV2X), and so on. Enabling support for non-terrestrial networks has been a direction being explored in the Third Generation Partnership Project (3GPP). Summary of the Invention

[0006] Some aspects of the present disclosure relate to apparatuses and methods for implementing techniques for a paging function between a user equipment (UE) and a non-terrestrial wireless network (NTN). Before a paging message is received by the UE, a paging alert signal (PAS) is received by the UE. In some embodiments, the PAS is sent with a higher priority than the physical downlink control channel (PDCCH), or occupies 127 subcarriers in the frequency domain. The implemented techniques may be applicable to many wireless systems, such as wireless communication systems based on the 3rd Generation Partnership Project (3GPP) Release 15 (Rel-15), Release 16 (Rel-16), Release 17 (Rel-17), etc.

[0007] Some aspects of the present disclosure relate to a UE. The UE may include a transceiver configured to enable wireless communication in NTN and a processor communicatively coupled to the transceiver. The processor may receive a synchronization signal from the NTN and also receive a paging alert signal (PAS), where the PAS is associated with the synchronization signal based on a frequency offset or a time offset relative to the synchronization signal. In some embodiments, the synchronization signal may include a primary synchronization signal (PSS) and a secondary synchronization signal, and the PAS may include an M-sequence or a Zadoff-Chu sequence that may occupy one symbol. In some embodiments, the one symbol is a first symbol, and the PAS may be repeated multiple times, thereby occupying consecutive symbols adjacent to the first symbol. In some embodiments, the PAS may indicate a paging occasion associated with the PAS. In some embodiments, the PAS may be discarded when there is a conflict with another signal. In some embodiments, the PAS is transmitted with a higher priority than the PDCCH or occupies 127 subcarriers in the frequency domain.

[0008] After that, the processor may receive information indicating a paging occasion associated with the PAS, and the information indicating the paging occasion is carried by the PDCCH. A time gap between the paging occasion and the PAS may be determined by a base station of the NTN. In response to the received information indicating the paging occasion, the processor may also receive a paging message carried by a physical downlink shared channel (PDSCH).

[0009] According to some aspects, the paging occasion may be a first paging occasion, and the PAS may be associated with a plurality of paging occasions including the first paging occasion and a second paging occasion. The processor may receive information indicating the second paging occasion, and the information may be carried by a second PDCCH, and receive a second paging message carried by a second PDSCH. In some embodiments, the paging occasion is the first paging occasion, the PAS is a first PAS, and the processor may also receive a second PAS associated with the synchronization signal from the NTN, where the second PAS is associated with the second paging occasion. After that, the processor may receive information indicating the second paging occasion associated with the second PAS, and the information indicating the second paging occasion is carried by the second PDCCH. After that, the processor may receive a second paging message carried by the second PDSCH.

[0010] According to some aspects, the synchronization signal is a first synchronization signal, and the processor may also receive a second synchronization signal from the NTN and receive a paging alert signal (PAS) associated with the second synchronization signal based on a second frequency offset or a second time offset determined by the NTN.

[0011] According to some aspects, the synchronization signal is a first synchronization signal, and the processor may receive a plurality of additional synchronization signals without an associated paging alert signal, wherein the number of synchronization signals is determined by a density parameter configured by the base station.

[0012] The present disclosure is provided for illustrative purposes only to provide an understanding of the subject matter described herein. Accordingly, the above features are merely examples and should not be construed as narrowing the scope or essence of the subject matter in the present disclosure. Other features, aspects, and advantages of the present disclosure will become apparent from the following detailed description, the drawings, and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings incorporated herein and forming a part of the specification illustrate the present disclosure and, together with the specification, further serve to explain the principles of the present disclosure and enable a person skilled in the relevant art to make and use the present disclosure.

[0014] Figure 1 A non-terrestrial wireless network (NTN) including a user equipment (UE) for receiving a paging alert signal associated with a paging occasion is shown in accordance with some aspects of the present disclosure.

[0015] Figure 2 A block diagram of a UE including a transceiver for receiving a paging alert signal associated with a paging occasion in an NTN is shown in accordance with some aspects of the present disclosure.

[0016] Figure 3 An example process performed by a UE for receiving a paging alert signal associated with a paging occasion in an NTN is shown in accordance with some aspects of the present disclosure.

[0017] Figures 4A to 4D An example process performed by a UE for receiving a paging alert signal associated with a paging occasion in an NTN is shown in accordance with some aspects of the present disclosure.

[0018] Figure 5 is an example computer system for implementing some aspects or portions of the disclosure provided herein.

[0019] The present disclosure is described with reference to the drawings. In the drawings, generally, like reference numerals indicate like or functionally similar elements. Additionally, generally, the leftmost digit of a reference numeral identifies the drawing in which the reference numeral first appears. DETAILED DESCRIPTION

[0020] A non-terrestrial wireless network (NTN) or non-terrestrial network can refer to any network involving non-terrestrial flying objects. NTN can include satellite communication networks, high-altitude platform systems (HAPS), air-to-ground networks, low-altitude unmanned aerial vehicles (UAVs, also known as drones), or any other NTN network. Due to the long distances that signals travel and the relative movement of user equipment (UE) or satellites in NTN, UEs may experience various performance issues in NTN.

[0021] In a wireless network such as NTN, when a UE does not have any ongoing data transmissions, the UE can enter an idle state to conserve battery. If new data arrives at the UE, the network can probe the UE by transmitting a paging message, and the UE responds accordingly. A paging occasion can be a specific subframe within a paging frame, where the network searches for idle UEs to deliver data to them. Thus, the UE can wake up in a specific subframe (such as subframe 0, 4, 5, or 9 within a radio frame). These specific subframes within the paging frame when the UE wakes up are called paging occasions (POs). A PO-based paging process can be implemented to deliver paging messages to the UE. Thus, when in the idle state, the UE can monitor paging messages based on POs at certain device-specific times. The UE can conserve battery because at other times, it can apply a discontinuous reception (DRX) process to turn off its receiver.

[0022] In some wireless systems such as the New Radio (NR) system, in addition to the downlink control information (DCI) carried by the physical downlink control channel (PDCCH), the paging function or paging occasion can also be triggered by a radio resource control (RRC) message. For example, in some embodiments, the paging function can be triggered by a paging early indication (PEI) or a wake-up signal (WUS) carried by the PDCCH. In addition to this, the paging message can be carried by the physical downlink shared channel (PDSCH). However, when the UE is placed in a pocket, backpack, or other low signal-to-noise ratio (SNR) or non-line-of-sight (NLOS) conditions, such as when the UE is in an NTN system, such paging mechanisms used in wireless systems may result in poor performance of the UE.

[0023] Some aspects of the present disclosure provide a mechanism for a UE to send a paging alert signal (PAS) to a UE as system information, which is sent with a higher priority than the PDCCH. In some embodiments, the PAS occupies 127 subcarriers in the frequency domain. Thus, the PAS is different from the PEI or WUS carried by the PDCCH in other systems. The PAS can be sent in association with the synchronization signal / PBCH block (SSB) to indicate to the UE one or more upcoming paging occasions. In the case where the UE is in a low-power mode to prepare for receiving a paging message, such a PAS sent by the system information before the paging occasion can wake up the UE. The PAS can be sent as an M sequence or as a Zadoff-Chu sequence. There may be a frequency offset or a time offset between the SSB and the paging alert signal. In addition, the PAS can be repeated a predetermined number of times before the paging occasion associated with the PAS. The following description is presented according to NTN. However, the technology is not limited to NTN, but can be applied to any wireless system.

[0024] Figure 1 A wireless system (e.g., an NTN 100 including a UE 101 for receiving a paging alert signal associated with a paging occasion) is shown in accordance with some aspects of the present disclosure. The NTN 100 is provided for illustrative purposes only and does not limit the disclosed aspects.

[0025] The NTN 100 may include, but is not limited to, a UE 101, a base station 103, a satellite 102, a gateway 104, and a core network 105. The UE 101 communicates with the satellite 102 via a service link 111, and the satellite 102 communicates with the gateway 104 via a feeder link 113. The satellite 102 may include a network node or a transceiver for wireless communication. There may be various specific implementations of the NTN 100. For example, the base station 103 and the gateway 104 may be integrated into one unit instead of being separate components. The base station 103 and the core network 105 may implement the functions of a normal terrestrial wireless network without a satellite, while the gateway 104 may implement the functions between the terrestrial wireless network and the satellite 102.

[0026] In some embodiments, when the base station 103 is located on the ground, the NTN 100 may have a transparent payload. In some embodiments, when the base station 103 may be located on the satellite 102, the NTN 100 may have a regenerative payload. There may be multiple satellites carrying base stations that communicate with each other. There may be other network entities not shown, such as a network controller, a relay station. The NTN may be referred to as a wireless network, a wireless communication system, or some other name known to those of ordinary skill in the art.

[0027] In some embodiments, the NTN 100 can be an NTN with a non-terrestrial flying object (e.g., satellite 102). In some embodiments, the NTN 100 can include a satellite communication network that includes satellite 102, HAPS, or an air-to-ground network or UAV. There can be multiple satellites in the NTN 100. The satellite 102 can be a low Earth orbit (LEO) satellite, a medium Earth orbit (MEO) satellite, or a geostationary Earth orbit (GEO) satellite. The NTN 100 can be a HAPS, which can be an airborne platform including an airplane, a hot air balloon, and an airship. For example, the NTN 100 can include an international mobile communication base station, called HIBS. The HIBS system can provide mobile services in the same transmission frequency used by a land mobile network. The NTN 100 can be an air-to-ground network for providing in-flight connectivity for an airplane by utilizing a ground station that acts similarly to a base station in a land mobile network. The NTN 100 can also be a movable low-altitude UAV.

[0028] In some embodiments, the satellite 102 can be a GEO satellite deployed at an altitude of 35786 Km and is characterized by slowly moving around its orbital position relative to a certain point on the Earth. Compared with a land cellular system, a communication network based on a GEO satellite has a large propagation delay and high propagation loss that must be considered in the overall design of the satellite network. Additionally and alternatively, the satellite 102 can be an LEO satellite at an altitude of 300 km - 3000 km. Therefore, the satellite 102 can have a lower propagation delay, lower propagation loss, and higher Doppler shift than a GEO satellite.

[0029] According to some aspects, the base station 103 can be a fixed station or a mobile station. In some embodiments, the base station 103 can be located on the satellite 102. The base station 103 can also be referred to by other names, such as a base transceiver system (BTS), an access point (AP), a transmit / receive point (TRP), an evolved Node B (eNB), a next-generation Node B (gNB), a 5G Node B (NB), or some other equivalent terms.

[0030] According to some aspects, the UE 101 may include a processor 109 and a memory 122. The UE 101 may be stationary or mobile. The UE 101 may be a handheld terminal or a very small aperture terminal (VSAT) equipped with a parabolic antenna and typically mounted on a building or a vehicle. The UE 101 may be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a desktop computer, a cordless phone, a wireless local loop station, a tablet computer, a camera, a gaming device, a netbook, a superbook, a medical device or equipment, a biometric sensor or device, a wearable device (smart watch, smart clothing, smart glasses, smart wristband, smart jewelry such as a smart ring or a smart bracelet), an entertainment device (e.g., a music or video device, or a satellite radio), a vehicle component, a smart meter, industrial manufacturing equipment, a global positioning system device, an Internet of Things (IoT) device, a machine type communication (MTC) device, an evolved or enhanced machine type communication (eMTC) device, or any other suitable device configured to communicate via a wireless medium. For example, MTC and eMTC devices may include robots, drones, location tags, etc.

[0031] According to some aspects, the UE 101 may be in an idle state, which means that it is not currently communicating with other devices (such as a base station) of the NTN 100. Paging is used to alert the UE 101 that there is data waiting for the UE 101 on the network. When the NTN 100 has data to send to the UE 101, the NTN 100 or its core network may initiate a paging process by transmitting a paging message to all the cells to which the UE 101 has registered. The message includes the identity of the UE 101 and the location of the cell where the UE 101 is expected to be located. The UE 101 monitors the paging channel of the cell that the UE 101 is currently camped on and will respond to the paging message if the UE 101 recognizes its identity in the paging message. If the UE 101 does not respond within a certain time frame, the network will assume that the UE 101 is unavailable and will retry the paging process in other cells where the UE 101 is registered.

[0032] According to some aspects, a paging frame is a radio frame in which a UE 101 monitors a paging channel (PCH) for paging messages. The paging frame may be specified in System Information Block Type 2 (SIB2) and is typically set to a value aligned with the radio frame boundary of the cell of the UE 101. A paging occasion is a specific subframe within the paging frame in which the network searches for idle UEs to deliver data to them. The UE 101 may wake up in a specific subframe among subframes 0, 4, 5, or 9 within the radio frame. Thus, these specific subframes within the paging frame when the UE 101 wakes up are referred to as paging occasions. Paging occasions are used to minimize signaling overhead by restricting the number of subframes in which the network searches for idle UEs.

[0033] In some embodiments, a paging occasion is determined by a combination of a paging cycle and the radio frame number (RFN) of the cell. The paging cycle determines the interval between consecutive paging occasions. The RFN of the cell is a counter that increments with each radio frame. The paging frame specifies the radio frame within the paging cycle in which the network transmits paging messages. In some embodiments, the paging frame may be set to any value from 0 to 1023, and different UEs may have different paging frames to avoid conflicts. A paging group ID may be used to identify a group of UEs that share the same paging cycle, paging frame, and paging subframe. The paging group ID is used to reduce the paging overhead by minimizing the number of UEs that need to be paged. The UE 101 may apply a discontinuous reception (DRX) procedure to turn off its receiver. The paging DRX parameter may specify the frequency at which the UE 101 should wake up to check for paging messages. The paging DRX parameter may be expressed in terms of the number of radio frames, with its value ranging from 32 to 5120 frames. A longer DRX cycle may help reduce power consumption but may also result in a longer delay in receiving paging messages.

[0034] In some embodiments, the processor 109 may be configured to establish a communication connection with the base station 103 using a transceiver (not shown). The processor 109 may receive a synchronization signal 121 from the NTN 100 and also receive a paging alert signal (PAS) 123. In some embodiments, the PAS 123 may occupy 127 subcarriers in the frequency domain or have a higher priority than the PDCCH. The PAS 123 may be associated with the synchronization signal based on a frequency offset or a time offset relative to the synchronization signal 121. The PAS 123 may indicate a paging occasion 125 associated with the PAS 123. In addition, the processor 109 may receive information indicating the paging occasion 125 associated with the PAS 123, where the information indicating the paging occasion 125 may be carried by the PDCCH. In response to the received information indicating the paging occasion 125, the processor 109 may receive a paging message 127 carried by the physical downlink shared channel (PDSCH).

[0035] According to some aspects, it may be based on, for exampleFigure 2 UE 101 is implemented by the illustrated block diagrams. Refer to Figure 2 , UE 101 may have an antenna panel 217, which includes one or more antenna elements to form various transmission beams, such as transmission beam 213. The one or more antenna elements are coupled to transceiver 203 and controlled by processor 109. Transceiver 203 and antenna panel 217 (using transmission beam 213) may be configured to implement wireless communication in a wireless network. Specifically, transceiver 203 may include radio frequency (RF) circuit 216, transmission circuit 212, and reception circuit 214. RF circuit 216 may include multiple parallel RF chains, which are used for one or more of the transmission or reception functions. Each RF chain is connected to one or more antenna elements of the antenna panel. In addition, processor 109 may be communicatively coupled to memory 122, which is further coupled to transceiver 203. Various data may be stored in memory 122, such as data decoded from synchronization signal 121, PAS 123, paging occasion 125, and paging message 127.

[0036] In some embodiments, memory 122 may include instructions that, when executed by processor 109, perform the operations described herein. For example, the operation of receiving a paging alert signal associated with a paging occasion. Alternatively, processor 109 may be "hard-coded" to perform the operations described herein. The operations performed by processor 109 or UE 101 may include the operations as shown Figure 3 as follows.

[0037] Figure 3 An example process 300 performed by a UE for receiving a paging alert signal associated with a paging occasion in an NTN according to some aspects of the present disclosure is shown. According to some aspects, as Figure 3 shown, process 300 may be performed by UE 101, processor 109, or caused to be implemented by processor 109 or by system 500.

[0038] At 301, UE 101 may receive synchronization signal 121 from NTN 100. In some embodiments, synchronization signal 121 may be a primary synchronization signal (PSS) or a secondary synchronization signal (SSS). Synchronization signal 121 may include a synchronization signal block (SSB). The purpose of PSS is initial symbol alignment and coarse frequency correction. In some embodiments, PSS may be a 127-element frequency division multiplexing (FDM)-based binary phase shift keying (BPSK) M sequence, and thus occupies 127 subcarriers, which is known to those of ordinary skill in the art.

[0039] At 303, the UE 101 may receive PAS 123. In some embodiments, PAS 123 may be sent as system information instead of being carried by the PDCCH, where the system information may have a higher priority than the PDCCH. PAS 123 may occupy 127 subcarriers in the frequency domain. In some embodiments, similar to the PSS, PAS 123 may include an M sequence or a Zadoff Chu sequence. PAS 123 may be associated with the synchronization signal 121 according to a frequency offset or a time offset relative to the synchronization signal 121. In some embodiments, the base station 103 may configure the frequency offset between the SSB and PAS 123. In some other embodiments, the base station 103 may configure the time offset between the SSB and PAS 123.

[0040] In some embodiments, PAS 123 may indicate the paging occasion associated with PAS 123. The base station 103 may configure the time period between the transmission of PAS 123 and the associated PO. The value range of this time period may be at the level of seconds or minutes. After this time period, when the UE 101 detects PAS 123, the UE 101 may be ready to detect the paging information or paging message.

[0041] In some embodiments, PAS 123 may include an M sequence or a Zadoff Chu sequence that may occupy one symbol. More details of the PAS shown as an M sequence or a Zadoff Chu are shown in the description for Figures 4A to 4D

[0042] At 305, the UE 101 may receive information associated with the paging occasion 125 associated with the paging PAS 123, and the information associated with the paging occasion 125 may be carried by the PDCCH. In some embodiments, the information associated with the paging occasion 125 may include control information related to a group of UEs to identify the group of UEs, such that the UE 101 may determine whether the UE 101 is included in the group of UEs to receive the upcoming paging message.

[0043] At 307, based on the received information associated with the paging occasion 125, the UE 101 may receive the paging message 127 carried by the physical downlink shared channel (PDSCH).

[0044] Figures 4A to 4D An example process for receiving a paging alert signal associated with a paging occasion in the NTN performed by the UE 101 (or performed by the processor 109 or caused to be performed by the processor 109) according to some aspects of the present disclosure is shown, such as process 400, process 410, process 420, and process 430. Process 400, process 410, process 420, and process 430 may be examples of process 300 shown with more, fewer, or different details.

[0045] Process 400 Figure 4A It is shown in Figure 3 An example of process 300 is shown. As shown, time flows from left to right, and various time instances (such as T1, T2, ..., T9) have a time order, where T1 <T2<……<T9。

[0046] Initially, at time instance T1, UE 101 may receive SSB 401 carrying a synchronization signal from NTN 100. Thereafter, at time instance T2, UE 101 may receive PAS 403 sent with a higher priority than PDCCH. In some embodiments, PAS 403 may occupy one symbol. In some embodiments, the one symbol may be the first symbol, and PAS 403 may be repeated multiple times, thereby occupying consecutive symbols 404 adjacent to the first symbol and being sent at time instance T3. In some embodiments, paging alert signal repetition may improve detection performance for UE 101. Base station 103 may configure the number of repeated symbols for paging alert signal transmission to {1, 2, ..., 8}. For example, a configuration of 4 may indicate that PAS 403 may be repeatedly sent to UE 101 in four consecutive symbols. In some embodiments, PAS 403 may indicate a paging occasion 405 associated with PAS 403. In some embodiments, PAS 403 may be discarded when there is a collision with another signal.

[0047] Thereafter, at time instance T6, UE 101 may receive information indicating paging occasion 405 associated with PAS 403, wherein the information indicating paging occasion 405 may be carried by PDCCH. The time gap between paging occasion 405 and PAS 403 may be determined by base station 103 of NTN 100.

[0048] Thereafter, at time instance T7, in response to the received information associated with the paging occasion 405, the UE 101 may also receive a paging message 407 carried by the PDSCH.

[0049] According to some aspects, paging occasion 405 may be a first paging occasion, and PAS 403 may be associated with a plurality of paging occasions including paging occasion 405 and a second paging occasion 406. At time instance T8, UE 101 may also receive information indicating second paging occasion 406, and at time instance T9, also receive a second paging message 408 carried by a second PDSCH.

[0050] According to some aspects, the synchronization signal carried by SSB 401 may be the first synchronization signal, and UE 101 may receive a plurality of additional synchronization signals carried by SSB 402a received at time instance T4 and SSB 402b received at time instance T5 without an associated paging alert signal. As Figure 4A shown, SSB 402a is sent without sending an associated PAS. The number of synchronization signals (such as SSB402a, SSB 402b) sent without an associated PAS is determined by a density parameter configured by base station 103. In some embodiments, to save system overhead, the paging alert signal density may be controlled by core network 105. In some embodiments, base station 103 may configure the paging alert signal density in a DRX / paging cycle such that only the paging occasion in the last paging frame has an associated paging alert signal transmission. In some other embodiments, the paging alert signal density may be defined based on a paging alert signal cycle, where one paging warning cycle may include several paging cycles. In some embodiments, the paging alert signal cycle is relative to an SSB burst set, which may be configured to have multiple SSB periodicities, such as SSB-periodicity {5, 10, 20, 40, 80, 160} ms, and the paging alert signal cycle may be defined as K*SSB-periodicity, where K = 1, 2, 3,... or any integer. In some embodiments, the paging alert signal cycle may include multiple paging cycles or an extended paging cycle.

[0051] In some embodiments, PAS 403 may have a defined priority. If PAS 403 has a lower priority than a conflicting channel or signal, PAS 403 may be discarded without delay. For example, when an SSB or PDCCH has a higher priority than PAS 403, PAS 403 may be discarded in case of a conflict. In some embodiments, PAS403 may always be discarded in case of a conflict, or discarded due to a DL to UL handover.

[0052] Procedure 410 is shown in Figure 4B where UE 101 may receive a paging alert signal associated with a paging occasion in an NTN. Procedure 410 may be an Figure 3 example of procedure 300 as shown. As shown, time flows from left to right, and various time instances (such as T1, T2,..., T9) have a time order, where T1 < T2 <... < T9.

[0053] Initially, at time instance T1, UE 101 may receive an SSB 411 carrying a synchronization signal from NTN 100. Subsequently, at time instance T2, UE 101 may receive a PAS 413a transmitted with a higher priority than the PDCCH. In some embodiments, PAS 413a may occupy one symbol. PAS 413a may indicate a paging occasion 415 associated with PAS 413a.

[0054] In some embodiments, paging occasion 415 is the first paging occasion, PAS 413a is the first PAS, and UE 101 may also receive a second PAS 413b associated with synchronization signal 411 at time instance T3, where the second PAS 413b indicates a second paging occasion 416.

[0055] Subsequently, at time instance T6, UE 101 may receive information associated with paging occasion 415 associated with PAS 413a, where the information associated with paging occasion 415 may be carried by a PDCCH. Subsequently, in response to the received information associated with paging occasion 415, at time instance T7, UE 101 may also receive a paging message 417 carried by a PDSCH.

[0056] In addition, at time instance T8, UE 101 may receive information associated with a second paging occasion 416 associated with the second PAS 413b, where the information associated with the second paging occasion 416 is carried by a second PDCCH. Subsequently, at time instance T9, UE 101 may receive a second paging message 418 carried by a second PDSCH.

[0057] In addition, UE 101 may receive a plurality of additional synchronization signals carried by an SSB 412a received at time instance T4 and an SSB 412b received at time instance T5 without an associated paging alert signal.

[0058] Procedure 420 is shown in Figure 4C where UE 101 may receive a paging alert signal associated with a paging occasion in the NTN. Procedure 420 may be an example of procedure 300 shown in Figure 3 As shown, time flows from left to right, and various time instances (such as T1, T2, ……, T12) have a time sequence, where T1 < T2 < …… < T12. For simplicity, some operations are described without stating time instances.

[0059] Initially, at time instance T1, UE 101 may receive an SSB 421a carrying a synchronization signal from NTN 100. Subsequently, at time instance T2, UE 101 may receive a PAS 423a transmitted with a higher priority than the PDCCH. The PAS 423a may indicate a paging occasion 425a associated with the PAS 423a. At time instance T12, UE 101 may receive information associated with the paging occasion 425a associated with the PAS 423a, where the information associated with the paging occasion 425a may be carried by the PDCCH. Subsequently, based on the received information associated with the paging occasion 425a, UE 101 may also receive a paging message 427a carried by the PDSCH.

[0060] According to some aspects, the synchronization signal included in the SSB 421a is a first synchronization signal. At time instance T4, UE 101 may also receive an SSB 421b including a second synchronization signal from NTN, and at time instance T5, receive a PAS 423b associated with the second synchronization signal in the SSB 421b according to a second frequency offset or a second time offset determined by NTN. The PAS 423b indicates a paging occasion 425b associated with the PAS 423b. At time instance T12, UE 101 may receive information associated with the paging occasion 425b associated with the PAS 423b, where the information associated with the paging occasion 425b may be carried by the PDCCH. Subsequently, based on the received information associated with the paging occasion 425b, UE 101 may also receive a paging message 427b carried by the PDSCH.

[0061] In addition, at time instance T7, UE 101 may also receive an SSB 421c including a third synchronization signal from NTN, and at time instance T8, receive a PAS 423c associated with the third synchronization signal in the SSB 421c. The PAS 423c indicates a paging occasion 425c associated with the PAS 423c. At T12, UE 101 may receive information associated with the paging occasion 425c associated with the PAS 423c, where the information associated with the paging occasion 425c may be carried by the PDCCH. Subsequently, based on the received information associated with the paging occasion 425c, UE 101 may also receive a paging message 427c carried by the PDSCH.

[0062] In addition, at time instance T10, UE 101 may also receive SSB 421d including the fourth synchronization signal from the NTN, and receive PAS 423d associated with the fourth synchronization signal in SSB 421d at time instance T11. PAS 423d indicates the paging occasion 425d associated with PAS 423d. At T12, UE 101 may receive information associated with the paging occasion 425d associated with PAS 423d, where the information associated with the paging occasion 425d may be carried by PDCCH. Subsequently, in response to the received information associated with the paging occasion 425d, UE 101 may also receive the paging message 427d carried by PDSCH.

[0063] In addition, UE 101 may receive a plurality of additional synchronization signals carried by SSB 422a and SSB 422b without an associated paging alert signal.

[0064] Procedure 430 is shown in Figure 4D where UE 101 may receive a paging alert signal associated with a paging occasion in the NTN. Procedure 420 may be an example of procedure 300 shown in Figure 3 Figure 300. As shown, time flows from left to right. For simplicity, operations are described without stating time instances.

[0065] Initially, UE 101 may receive SSB 431a carrying a synchronization signal from NTN 100. Subsequently, UE 101 may receive PAS 433a transmitted with a higher priority than PDCCH. PAS 433a may indicate the paging occasion 435a associated with PAS 433a. UE 101 may receive information associated with the paging occasion 435a associated with PAS 433a, where the information associated with the paging occasion 435a may be carried by PDCCH. Subsequently, based on the received information associated with the paging occasion 435a, UE 101 may also receive the paging message 437a carried by PDSCH based on the information associated with the paging occasion 435a. In addition, UE 101 may receive another PAS 432a indicating the paging occasion 439 associated with PAS 432a. Details of the paging occasion 439 are not shown but are similar to the paging occasion of PAS 433a.

[0066] According to some aspects, the synchronization signal included in SSB 431a is the first synchronization signal. UE 101 may also receive SSB 431b including a second synchronization signal from NTN and receive PAS 433b associated with the second synchronization signal in SSB 431b. PAS 433b will indicate the paging occasion 435b associated with PAS 433b. UE 101 may receive information associated with the paging occasion 435b associated with PAS 433b, where the information associated with the paging occasion 435b may be carried by PDCCH. Thereafter, based on the received information associated with the paging occasion 435b, UE 101 may also receive a paging message 437b carried by PDSCH. In addition, UE 101 may receive another PAS 432b indicating the paging occasion 439 associated with PAS 432b, where the paging occasion 439 is different from the paging occasion associated with PAS 433a.

[0067] In addition, UE 101 may also receive SSB 431c including a synchronization signal from NTN and receive PAS 433c associated with the synchronization signal in SSB 431c. PAS 433c indicates the paging occasion 435c associated with PAS 433c. UE101 may receive information associated with the paging occasion 435c associated with PAS 433c, where the information associated with the paging occasion 435c may be carried by PDCCH. Thereafter, based on the received information associated with the paging occasion 435c, UE 101 may also receive a paging message 437c carried by PDSCH. In addition, UE 101 may receive another PAS 432c indicating the paging occasion 439 associated with PAS 432c.

[0068] In addition, UE 101 may also receive SSB 431d including a synchronization signal from NTN and receive PAS 433d associated with the synchronization signal in SSB 431d. PAS 433d indicates the paging occasion 435d associated with PAS 433d. UE101 may receive information associated with the paging occasion 435d associated with PAS 433d, where the information associated with the paging occasion 435d may be carried by PDCCH. Thereafter, based on the received information associated with the paging occasion 435d, UE 101 may also receive a paging message 437d carried by PDSCH. In addition, UE 101 may receive another PAS 432d indicating the paging occasion 439 associated with PAS 432d.

[0069] In some embodiments, various PASs (such as PAS 433a, PAS 433b, PAS 433c, PAS 433d, PAS432a, PAS 432b, PAS 432c, PAS 432d, PAS 423a, PAS 423b, PAS 423c, PAS 423d, PAS 413a, PAS 413b, and PAS 403) may be similar to PSSs and occupy one symbol with 127 subcarriers. The various PASs may be formed as M sequences. An M sequence is a linear feedback shift register (LFSR) sequence. An LFSR is a shift register circuit where two or more outputs from intermediate steps are linearly combined and fed back to the input value.

[0070] Generally, the M sequence d PAS (n) for the paging alert signal is defined by d PAS (n)=1 - 2x(m), where and x(i + 7)=(x(i + 4)+x(i))mod2 and [x(6)x(5)x(4)x(3)x(2)x(1)]=[1110110]. The parameters Z and are determined according to the number of paging opportunities in the paging frame, and is the paging opportunity index in the paging frame. The parameter Z can be configurable or predefined in the specification. Some examples of and parameter Z are provided below as examples for generating M sequences, which can be used as PAS433a, PAS 433b, PAS 433c, PAS 433d, PAS 432a, PAS 432b, PAS 432c, PAS 432d, PAS 423a, PAS 423b, PAS 423c, PAS 423d, PAS 413a, PAS 413b, and PAS 403.

[0071] In some embodiments, each paging opportunity may have its own associated paging alert signal, as Figure 4D shown. The paging alert signals for different paging opportunities may be sent in different symbols.

[0072] In some embodiments, if Ns = 1, then Z = 0. If Ns = 2, then Z = 64 or Z = 0. The first paging opportunity (i.e., ) is sent in the first symbol for paging alert. The second paging opportunity (i.e., ) is sent in the second symbol for paging alert, as Figure 4D shown. If Ns = 4, then Z = 32 or Z = 0. Four paging alert signals are transmitted in four symbols for four paging occasions.

[0073] In some embodiments, one paging alert signal can be shared by different paging occasions with different cyclic shifts, where the paging alert signal occupies one symbol. If Ns = 1, then Z = 0. If the UE detects a paging alert signal for a paging occasion, the UEs in the group are paged.

[0074] In some embodiments, if Ns = 2, then Z = 32. The generated sequence means 01, and the UEs in paging occasion #0 are paged The generated sequence means 10, and the UEs in paging occasion #1 are paged The generated sequence means 11, and the UEs in both paging occasion #0 and paging occasion #1 are paged. The generated sequence means 00, and the UEs in neither paging occasion #0 nor paging occasion 1# are paged.

[0075] If Ns = 4, then Z = 16. A total of eight sequences are generated, and one sequence represents the states of four paging occasion combinations, for example, 0100.

[0076] If Ns = 2, then Z = 43

[0077] If Ns = 4, then Z = 19

[0078] For example, if there are four POs in a paging frame, i.e., Ns = 4. For example, if the UE belongs to the third paging alert group, for example, If the UE detects a paging alert signal by correlating the paging alert sequence, the UE will know that it is paged and be ready to receive paging information.

[0079] In some embodiments, for the case where no UEs are paged at any paging occasion, one sequence may be unnecessary. Such as for Ns = 2, " The generated sequence means 00, and the UEs in neither paging occasion #0 nor paging occasion 1# are paged.

[0080] In some embodiments, various PASs (such as PAS 423a, PAS 423b, PAS 423c, and PAS 423d) can be Zadoff Chu (ZC) sequences.

[0081] In some embodiments, the base sequences of multiple PASs can be selected according to a known method, such as those defined in Section 5.2.2 of TS38.213. The length of the base sequence can be equal to or greater than 12 (e.g., 12, 18, 24, 30) or greater than 36. There can be 30 base sequences, A paging alert signal can be shared by different paging occasions, and the paging alert signal occupies one symbol.

[0082] In some embodiments, the base sequence offset k offset can be configured by the network on top of the base sequences selected below. The base sequence for Ns is predefined or configurable. For example, if Ns = 1, i.e., one paging occasion in the paging frame, the first base sequence can be applied. If the UE detects the first base sequence, the UE will know that it is being paged. The base sequence offset can be in the range of {0, 1, …, 29}.

[0083] In some embodiments, if Ns = 2, it indicates two paging occasions in the paging frame. Four base sequences can be selected k offset +1 + n*7 n = 0, 1, 2, 3. If k offset = 0, the 1st, 8th, 15th, and 22nd base sequences are applied to the paging warning indication. k offset can be in the range of {0, 1, 2, 3, 4, 5, 6}. The 1st sequence means 00, and UEs in neither paging occasion #0 nor paging occasion 1# are paged. The 8th sequence means 01, and the UE in paging occasion #0 is paged. The 15th sequence means 10, and the UE in paging occasion #1 is paged. The 22nd sequence means 11, and UEs in both paging occasion #0 and paging occasion #1 are paged.

[0084] In some embodiments, if Ns = 4, i.e., there are four paging occasions in the paging frame. The eighth base sequence is selected k offset +1 + n*3 n = 0, 1,.., 7. The 1st, 4th, 7th, 10th, 13th, 16th, 19th, 22nd base sequences are applied to the paging alert indication. The base sequence offset can be in the range of {0, 1, 2}.

[0085] In some embodiments, a cyclic shift-based ZC sequence can be selected for the paging alert signal. The length of the base sequence can be equal to or greater than 12 (e.g., 12, 18, 24, 30) or greater than 36. The base sequence can be defined in Section 5.2.2 of TS38.213. The cyclic shift α is determined according to the base sequence length and the number of paging occasions per paging frame.

[0086] In some embodiments, the initial cyclic shift offset m0 Can be configured by the network Wherein is the ZF sequence after a cyclic shift α, is the basic sequence, m 0 is the initial cyclic shift offset configured by the network, m cs is the cyclic shift determined by Ns, and its value can be predefined m cs or may be configurable by the base station 103, and M ZC is the length of the ZC sequence.

[0087] In some embodiments, m cs is predefined. If Ns = 1, i.e., one paging occasion in the paging frame, then m cs = 0, there is no cyclic shift, or if it is configured, the cyclic shift is equal to m 0 . If Ns = 2, i.e., two paging occasions in the paging frame, then m cs = k*floor(N ZC / 4) k = 0, 1, 2, 3, and four cyclic shifts are applied to generate four paging alert signals. The sequence with the cyclic shift m cs where k = 0 means 00, and the UE in paging occasion #0 is paged. The sequence with the cyclic shift m cs where k = 1 means 01, and the UE in paging occasion #1 is paged. The sequence with the cyclic shift m cs where k = 2 means 10, and the UEs in neither paging occasion #0 nor paging occasion 1# are paged. The sequence with the cyclic shift m cs where k = 3 means 11, and the UEs in neither paging occasion #0 nor paging occasion #1 are paged. If Ns = 4, i.e., there are four paging occasions in the paging frame. Therefore, there is the formula m cs = k*floor(N ZC / 8) k = 0, 1,.., 7, and the eight generated ZC sequences are generated for paging alert signal indication. If Ns = 2, then m cs = k*floor(N ZC / 3) k = 0, 1, 2. If Ns = 4, then m cs = k*floor(N ZC / 7) k = 0, 1,.., 6.

[0088] Various aspects can be implemented, for example, using one or more computer systems (such as Figure 5 the computer system 500 shown). The computer system 500 can be any computer capable of performing the functions described herein, such as Figure 1 and Figure 2The UE 101 or base station 103 shown is for operations such as Figure 3 , Figures 4A to 4D the operation of the processor 109 or processes 300, 400, 410, 420, or 430 as described. The computer system 500 includes one or more processors (also referred to as central processing units or CPUs), such as processor 504. The processor 504 is connected to a communication infrastructure 506 (e.g., a bus). The computer system 500 also includes user input / output devices 503 that communicate with the communication infrastructure 506 via a user input / output interface 502, such as a monitor, keyboard, pointing device, etc. The computer system 500 also includes a main memory or primary storage 508, such as random access memory (RAM). The main memory 508 may include one or more levels of cache. Control logic (e.g., computer software) and / or data is stored in the main memory 508.

[0089] The computer system 500 may also include one or more secondary storage devices or memories 510. The secondary storage 510 may include, for example, a hard disk drive 512 and / or a removable storage device or drive 514. The removable storage drive 514 can be a floppy disk drive, tape drive, optical disk drive, optical storage device, tape backup device, and / or any other storage device / drive.

[0090] The removable storage drive 514 can interact with a removable storage unit 518. The removable storage unit 518 includes a computer-usable or readable storage device on which computer software (control logic) and / or data is stored. The removable storage unit 518 can be a floppy disk, tape, optical disk, DVD, optical storage disk, and / or any other computer data storage device. The removable storage drive 514 reads from and / or writes to the removable storage unit 518 in a well-known manner.

[0091] According to some aspects, the secondary storage 510 may include other components, tools, or other means for allowing the computer system 500 to access computer programs and / or other instructions and / or data. Such components, tools, or other means may include, for example, a removable storage unit 522 and an interface 520. Examples of the removable storage unit 522 and the interface 520 may include a program cartridge and cartridge interface (such as found in video game devices), a removable memory chip (such as an EPROM or PROM) and associated socket, a memory stick and USB port, a memory card and associated memory card slot, and / or any other removable storage unit and associated interface.

[0092] In some examples, main memory 508, removable storage unit 518, and removable storage unit 522 may store instructions that, when executed by processor 504, cause processor 504 to perform operations for a UE or a base station (e.g., UE 101 or base station 103 as shown in Figure 1 and Figure 2 ). In some examples, the operations include those illustrated and described for processes 300, 400, 410, 420, or 430 as shown in Figure 3 、 Figures 4A to 4D .

[0093] Computer system 500 may also include a communication or network interface 524. Communication interface 524 enables computer system 500 to communicate and interact with any combination of remote devices, remote networks, remote entities, etc. (collectively and individually referred to by reference numeral 528). For example, communication interface 524 may allow computer system 500 to communicate with remote device 528 via communication path 526, which may be wired and / or wireless and may include any combination of LAN, WAN, the Internet, etc. Control logic and / or data may be sent to and from computer system 500 via communication path 526. The operation of communication interface 524 may be performed by a wireless controller and / or a cellular controller. The cellular controller may be a separate controller to manage communication according to different wireless communication technologies. The operations in the foregoing aspects can be implemented in various configurations and architectures. Thus, some or all of the operations in the foregoing aspects may be performed in hardware, in software, or in both hardware and software. In some aspects, a tangible, non-transitory device or article includes a tangible, non-transitory computer-usable or readable medium having control logic (software) stored thereon, also referred to herein as a computer program product or a program storage device. This includes, but is not limited to, computer system 500, main memory 508, auxiliary memory 510, and removable storage units 518 and 522, and any tangible article embodying any combination of the foregoing. Such control logic, when executed by one or more data processing devices (such as computer system 500), causes such data processing devices to operate as described herein.

[0094] Based on the teachings contained in this disclosure, it will be apparent to those skilled in the relevant art how to make and use aspects of this disclosure using data processing devices, computer systems, and / or computer architectures other than those shown in Figure 5 . In particular, aspects may operate in conjunction with software, hardware, and / or operating system implementations other than those described herein.

[0095] It should be understood that the detailed description section, rather than the summary and abstract sections, is intended to be used to interpret the claims. The summary and abstract sections may set forth one or more but not all exemplary aspects of the disclosure as contemplated by the inventor, and are therefore not intended to limit the disclosure or the appended claims in any way.

[0096] Although the present disclosure has been described herein with reference to exemplary aspects of exemplary fields and applications, it should be understood that the present disclosure is not limited thereto. Other aspects and modifications are possible and are within the scope and spirit of the present disclosure. For example, and without limiting the generality of this paragraph, aspects are not limited to the software, hardware, firmware, and / or entities shown in the figures and / or described herein. Additionally, aspects (whether explicitly described herein or not) have significant utility for fields and applications other than those described herein by way of example.

[0097] Aspects have been described herein by means of functional building blocks of specific implementations that illustrate particular functions and their relationships. For ease of description, the boundaries of these functional building blocks have been arbitrarily defined herein. Alternate boundaries may be defined so long as the specified functions and relationships (or their equivalents) are appropriately performed. Additionally, alternate aspects may perform the functional blocks, steps, operations, methods, etc. in an order different from that described herein.

[0098] References herein to "one embodiment", "an embodiment", "example embodiment", or similar phrases indicate that the described embodiment may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Additionally, when a particular feature, structure, or characteristic is described in connection with an embodiment, whether or not explicitly recited or described herein, it is within the knowledge of those skilled in the relevant art to incorporate such feature, structure, or characteristic into other aspects.

[0099] The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary aspects, but should be defined only in accordance with the following claims and their equivalents.

[0100] For one or more embodiments or examples, at least one of the components recited in one or more of the foregoing figures may be configured to perform one or more of the operations, techniques, processes, and / or methods recited in the example section below. For example, the circuitry associated with a thread device, router, network element, etc., as described above in connection with one or more of the foregoing figures, may be configured to operate in accordance with one or more of the examples recited in the example section below.

[0101] The present disclosure anticipates that entities responsible for the collection, analysis, disclosure, transfer, storage, or other use of such personal information data will comply with sound privacy policies and / or privacy measures. Specifically, such entities should implement and adhere to privacy policies and practices that are recognized as meeting or exceeding industry or government requirements for maintaining the privacy and security of personal information data. Such policies should be accessible to users and should be updated as the collection and / or use of data changes. Personal information from users should be collected for legitimate and reasonable entity purposes and should not be shared or sold outside of those legitimate purposes. Additionally, such collection / sharing should only occur upon receipt of user informed consent. Further, such entities should consider taking any necessary steps to protect and secure access to such personal information data and to ensure that other entities with access to personal information data comply with their privacy policies and procedures. Additionally, such entities may subject themselves to third-party assessments to demonstrate their compliance with widely accepted privacy policies and practices. Further, policies and practices should be adapted to the specific types of personal information data being collected and / or accessed and to the applicable laws and standards, including considerations of particular jurisdictions. For example, in the United States, the collection or acquisition of certain health data may be governed by federal and / or state laws such as the Health Insurance Portability and Accountability Act (HIPAA); while health data in other countries may be subject to other regulations and policies and should be handled accordingly. Therefore, different privacy measures should be asserted for different types of personal data in each country.

Claims

1. A method for performing wireless communications by a user equipment (UE) in a non-terrestrial wireless network (NTN), the method comprising: receiving a synchronization signal from the NTN; receiving a paging alert signal (PAS), wherein the PAS is associated with the synchronization signal according to a frequency offset or a time offset relative to the synchronization signal, wherein the PAS indicates a paging occasion associated with the PAS; receiving information associated with the paging occasion, the information associated with the paging occasion being carried by a physical downlink control channel (PDCCH); as well as A paging message carried by a physical downlink shared channel (PDSCH) is received based on the information associated with the paging occasion.

2. The method according to claim 1, wherein the PAS comprises an M sequence or a ZadoffChu sequence.

3. The method of claim 1 , wherein the paging occasion is a first paging occasion, and wherein the PAS is associated with a plurality of paging occasions including the first paging occasion and a second paging occasion, and the method further comprises: receiving information associated with the second paging occasion carried by a second PDCCH; as well as A second paging message carried by a second PDSCH is received.

4. The method of claim 1, wherein the paging occasion is a first paging occasion, the PAS is a first PAS, and the method further comprises: receiving, from the NTN, a second PAS associated with the synchronization signal, wherein the second PAS is associated with a second paging occasion; as well as receiving information associated with the second paging occasion, where the information associated with the second paging occasion is carried by a second PDCCH; as well as A second paging message carried by a second PDSCH is received. The method according to claim 1 , wherein the PAS occupies one symbol. 6 . The method of claim 5 , wherein the one symbol is a first symbol, and the PAS is repeated a plurality of times so as to occupy consecutive symbols adjacent to the first symbol.

7. The method according to claim 1, wherein the synchronization signal is a first synchronization signal, and the method further comprises: receiving a second synchronization signal from the NTN; The paging alert signal (PAS) is received in association with the second synchronization signal according to a second frequency offset or a second time offset determined by the NTN, wherein the PAS indicates the paging occasion associated with the PAS.

8. The method according to claim 1, wherein the synchronization signal is a first synchronization signal, and the method further comprises: A plurality of additional synchronization signals are received without an associated paging alert signal, wherein the number of synchronization signals is determined by a density parameter configured by the base station.

9. The method according to claim 1, wherein the synchronization signal is a synchronization signal including a primary synchronization signal (PSS) and a secondary synchronization signal and a PBCH block (SSB).

10. The method of claim 1, wherein the paging alert signal is discarded when there is a conflict with other signals or based on a priority rule defined between the paging alert signal and other signals. 11 . The method according to claim 1 , wherein the PAS occupies 127 subcarriers in the frequency domain, or the PAS has a higher priority than the PDCCH.

12. A user equipment (UE), the UE comprising: a transceiver configured to implement wireless communications in a non-terrestrial wireless network (NTN); and a processor communicatively coupled to the transceiver and configured to: receiving a synchronization signal from the NTN; receiving a paging alert signal (PAS), wherein the PAS is associated with the synchronization signal according to a frequency offset or a time offset relative to the synchronization signal, wherein the PAS indicates a paging occasion associated with the PAS; receiving information associated with the paging occasion, the information associated with the paging occasion being carried by a physical downlink control channel (PDCCH); as well as A paging message carried by a physical downlink shared channel (PDSCH) is received based on the information associated with the paging occasion. The UE according to claim 12 , wherein the PAS comprises an M sequence or a ZadoffChu sequence.

14. The UE of claim 12, wherein the paging occasion is a first paging occasion, and wherein the paging alert signal is associated with a plurality of paging occasions including the first paging occasion and a second paging occasion, and the processor is further configured to: receiving information associated with the second paging occasion carried by a second PDCCH; and A second paging message carried by a second PDSCH is received.

15. The UE of claim 12, wherein the paging occasion is a first paging occasion, the paging alert signal is a first PAS, and the processor is further configured to: receiving, from the NTN, a second PAS associated with the synchronization signal, wherein the second PAS is associated with a second paging occasion; as well as receiving information associated with the second paging occasion, where the second paging occasion is associated with the second PAS, and the information associated with the second paging occasion is carried by a second PDCCH; as well as A second paging message carried by a second PDSCH is received. The UE according to claim 12 , wherein the PAS occupies one symbol. 17 . The UE of claim 16 , wherein the one symbol is a first symbol, and the PAS is repeated a plurality of times so as to occupy consecutive symbols adjacent to the first symbol. 18 . The UE according to claim 12 , wherein the PAS occupies 127 subcarriers in the frequency domain, or the PAS has a higher priority than the PDCCH.

19. A non-transitory computer-readable medium storing instructions, which, when executed by a processor of a user equipment (UE), cause the UE to perform operations comprising: receiving a synchronization signal from the NTN; receiving a paging alert signal (PAS), wherein the PAS is associated with the synchronization signal according to a frequency offset or a time offset relative to the synchronization signal, wherein the PAS indicates a paging occasion associated with the PAS; receiving information associated with the paging occasion associated with the PAS, the information associated with the paging occasion being carried by a physical downlink control channel (PDCCH); as well as A paging message carried by a physical downlink shared channel (PDSCH) is received in response to the received information associated with the paging occasion.

20. The non-transitory computer readable medium of claim 19, wherein the paging occasion is a first paging occasion, and wherein the paging alert signal is associated with a plurality of paging occasions including the first paging occasion and a second paging occasion, and the operations further comprise: receiving information associated with the second paging occasion carried by a second PDCCH; as well as A second paging message carried by a second PDSCH is received.

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