WO2022241611A1

WO2022241611A1 - Timing advance pre-compensation information reporting in non-terrestrial network

Info

Publication number: WO2022241611A1
Application number: PCT/CN2021/094102
Authority: WO
Inventors: Ping Yuan; Chunli Wu; Pingping Wen
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy; Nokia Technologies Oy
Priority date: 2021-05-17
Filing date: 2021-05-17
Publication date: 2022-11-24
Also published as: CN117356139A

Abstract

Embodiments of the present disclosure relate to devices, methods, apparatuses and computer readable storage media of TA pre-compensation information reporting in NTN. The method comprises receiving, from a second device, an indication for reporting TA pre-compensation information from a first device to the second device. The indication is associated with an elevation angle of a satellite associated with the second device. The method further comprises determining the reporting of the TA pre-compensation information at least based on the indication. In this way, the UE may start and stop the reporting of TA pre-compensation information automatically based on criteria defined by network with less signaling overhead. No reporting reconfiguration requirement to enable/disable TA pre-compensation information reporting is needed from the gNB to the UE when the satellite is moving.

Description

TIMING ADVANCE PRE-COMPENSATION INFORMATION REPORTING IN NON-TERRESTRIAL NETWORK

FIELD

Embodiments of the present disclosure generally relate to the field of telecommunication and in particular to devices, methods, apparatuses and computer readable storage media of Timing Advance (TA) pre-compensation information reporting in non-terrestrial network (NTN) .

BACKGROUND

To support the radio access for satellite links in New Radio (NR) system, long round-trip delay is one issue to be addressed. Two types of User Equipments (UEs) should be considered for the pre-compensation of the estimated delay in Uplink (UL) transmission, namely the UE with capability of TA pre-compensation and the UE without capability of TA pre-compensation.

In the discussion of random access procedure adaption for NTN UE with capability of TA pre-compensation, the UE should first estimate the TA with respect to the satellite before UE sending Message1 (Msg1) based on UE received Global Navigation Satellite System (GNSS) information. Then UE may perform the Msg1 transmission by apply the estimated TA of the UE. For the Physical Uplink Shared Channel (PUSCH) scheduling, one way is the network may schedule PUSCH by using a TA based on a maximum Round-Trip Time (RTT) of UEs in the cell served by the network. The other way is the network may schedule PUSCH by using a UE-specific TA.

SUMMARY

In general, example embodiments of the present disclosure provide a solution of TA pre-compensation information reporting in NTN.

In a first aspect, there is provided a first device. The first device comprises at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device at least to receive, from a second device, an indication for reporting TA pre-compensation information from the first device to the second device, the indication being associated with an elevation angle of a satellite associated with the second device, and determine the reporting of the TA pre-compensation information at least based on the indication.

In a second aspect, there is provided a second device. The second device comprises at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device at least to generate an indication for reporting TA pre-compensation information from a first device to the second device based on an elevation angle of a satellite associated with the second device and transmit the indication to the first device.

In a third aspect, there is provided a method. The method comprises receiving, from a second device, an indication for reporting TA pre-compensation information from a first device to the second device, the indication being associated with an elevation angle of a satellite associated with the second device, and determining the reporting of the TA pre-compensation information at least based on the indication.

In a fourth aspect, there is provided a method. The method comprises generating an indication for reporting TA pre-compensation information from a first device to a second device based on an elevation angle of a satellite associated with the second device and transmitting the indication to the first device.

In a fifth aspect, there is provided an apparatus comprising means for receiving, from a second device, an indication for reporting TA pre-compensation information from a first device to the second device, the indication being associated with an elevation angle of a satellite associated with the second device, and means for determining the reporting of the TA pre-compensation information at least based on the indication.

In a sixth aspect, there is provided an apparatus comprising means for generating an indication for reporting TA pre-compensation information from a first device to a second device based on an elevation angle of a satellite associated with the second device and means for transmitting the indication to the first device.

In a seventh aspect, there is provided a computer readable medium having a computer program stored thereon which, when executed by at least one processor of a device, causes the device to carry out the method according to the third aspect.

In an eighth aspect, there is provided a computer readable medium having a computer program stored thereon which, when executed by at least one processor of a device, causes the device to carry out the method according to the fourth aspect.

Other features and advantages of the embodiments of the present disclosure will also be apparent from the following description of specific embodiments when read in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of embodiments of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the disclosure are presented in the sense of examples and their advantages are explained in greater detail below, with reference to the accompanying drawings, where

FIG. 1 illustrates an example environment in which example embodiments of the present disclosure can be implemented;

FIG. 2 shows a signaling chart illustrating a process of TA pre-compensation information reporting in NTN according to some example embodiments of the present disclosure;

FIG. 3 shows an example of criteria for reporting the TA pre-compensation information in NTN according to some example embodiments of the present disclosure;

FIG. 4 shows a flowchart of an example method of TA pre-compensation information reporting in NTN according to some example embodiments of the present disclosure;

FIG. 5 shows a flowchart of an example method of TA pre-compensation information reporting in NTN according to some example embodiments of the present disclosure;

FIG. 6 shows a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

FIG. 7 shows a block diagram of an example computer readable medium in accordance with some embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an example embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish functionalities of various elements. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.

As used in this application, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuits and software, such as (as applicable) :

(i) a combination of analog and/or digital hardware circuit (s) with software/firmware and

(ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as fifth generation (5G) systems, Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the future fifth generation (5G) new radio (NR) communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a NR Next Generation NodeB (gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology. A RAN split architecture comprises a gNB-CU (Centralized unit, hosting RRC, SDAP and PDCP) controlling a plurality of gNB-DUs (Distributed unit, hosting RLC, MAC and PHY) . A relay node may correspond to DU part of the IAB node.

The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE) , a subscriber station (SS) , a portable subscriber station, a mobile station (MS) , or an access terminal (AT) . The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , USB dongles, smart devices, wireless customer-premises equipment (CPE) , an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device and applications (e.g., remote surgery) , an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. The terminal device may also correspond to Mobile Termination (MT) part of the integrated access and backhaul (IAB) node (a. k. a. a relay node) . In the following description, the terms “terminal device” , “communication device” , “terminal” , “user equipment” and “UE” may be used interchangeably.

Although functionalities described herein can be performed, in various example embodiments, in a fixed and/or a wireless network node, in other example embodiments, functionalities may be implemented in a user equipment apparatus (such as a cell phone or tablet computer or laptop computer or desktop computer or mobile IoT device or fixed IoT device) . This user equipment apparatus can, for example, be furnished with corresponding capabilities as described in connection with the fixed and/or the wireless network node (s) , as appropriate. The user equipment apparatus may be the user equipment and/or or a control device, such as a chipset or processor, configured to control the user equipment when installed therein. Examples of such functionalities include the bootstrapping server function and/or the home subscriber server, which may be implemented in the user equipment apparatus by providing the user equipment apparatus with software configured to cause the user equipment apparatus to perform from the point of view of these functions/nodes.

FIG. 1 shows an example communication network 100 in which embodiments of the present disclosure can be implemented. As shown in FIG. 1, the communication network 100 may comprise terminal devices 110-1, 110-2 and 110-3. Hereinafter the terminal devices 110-1, 110-2 and 110-3 may also be referred to as the UE 110-1, the UE 110-2 and the UE 110-3, respectively. Alternatively, hereinafter the terminal devices 110-1, 110-2 and 110-3 may also be referred to as a first device 110 or a UE 110 collectively.

The communication network 100 may further comprise a network device 120 (hereinafter may also be referred to as a gNB 120 or a second device 120) . In a case where the communication network 100 refers to a NTN, the network device 120 can be considered as being located in a satellite or being located on earth with waveforms signal repeated by the satellite. The network device 120 can manage a cell 102. The terminal devices 110-1, 110-2 and 110-3 and the network device 120 can communicate with each other in the coverage of the cell 102.

It is to be understood that the number of network devices and terminal devices shown in FIG. 1 is given for the purpose of illustration without suggesting any limitations. The communication network 100 may include any suitable number of network devices and terminal devices.

As mentioned above, in a random access procedure for NTN, the UE, which has pre-compensation capability, shall first estimate the TA with respect to the satellite before UE sending Msg1 based on UE received GNSS information. Then UE may perform the Msg1 transmission by applying the estimated TA of the UE.

Furthermore, there are two ways for the network to schedule the PUSCH, namely schedule the PUSCH by using a TA based on a maximum RTT of UEs in the cell served by the network or using UE-specific TA. Herein the PUSCH transmission may be referred to as a Message 3 (Msg3) transmission or a Message (Msg5) transmission, which may be considered as PUSCH transmission after RA completion. It is to be understood that the PUSCH transmission herein can be referred to any PUSCH transmission, not limited to the PUSCH transmission in the random access procedure. For example, the PUSCH transmission may be PUSCH transmission when the UE is in RRC Connected state.

In a case where the PUSCH is scheduled by the network based on the maximum RTT, the maximum RTT may be referred to as a RTT between a gNB and a UE located in farthest end of coverage to satellite at which the gNB is located. For example, as shown in FIG. 1, the RTT between the UE 110-1 and the gNB 120 can be considered as the maximum RTT. The maximum RTT of UE 110-1 can be used to make sure all UEs (UE 110-1, 110-2 and 110-3) in the coverage have sufficient TA to transmit PUSCH. The maximum RTT can be broadcasted by the network to the UEs.

In another case, since the UEs may be located at different location in the coverage, for example, some of UEs can be located at near end of the coverage to the satellite, while other UEs can be located in far end of the coverage. If the UE can report its self-estimated TA, the network can schedule different UEs using UE-specific TA to save each UE’s scheduling delay. Obviously, the UEs located at the center of the cell’s coverage or at the near end of coverage can be scheduled with short RTT since it covers sufficient TA for these UEs to transmit PUSCH. In this way, the scheduling latency for UEs located at the center of the cell’s coverage or at the near end of coverage can be saved.

However, in the case where the PUSCH is scheduled by using UE-specific TA may reduce the coverage of the PUSCH. For example, if the information of value of TA applied by UE is added to the Message A (MsgA) PUSCH, the MsgA PUSCH payload size may be increased significantly, which will reduce the coverage of the PUSCH.

Furthermore, the complexity for the network will be increased by handling different TA for different UEs to achieve the gain. According to current network implementation principle in terrestrial network, one basic rule is that when the network schedules a group of UEs in the same Downlink (DL) scheduling slot (e.g., in the slot m) , the network may expect all the PUSCH transmissions from these UEs should arrive gNB in the same UL PUSCH slot (e.g., in the slot n) . Otherwise, it will be extraordinarily complex for the network to schedule UEs, because it must consider not only UE to be scheduled in current scheduling slot, but also the UEs already scheduled in previous slots and check if the scheduled UEs from different scheduling slot have same PUSCH transmission slot.

Therefore, it is expected that the network can control whether the UE reports TA pre-compensation information. It is also expected that the reporting of the UE specific TA can be triggered by some criteria detected by the UE itself.

The reported TA pre-compensation information can be the UE self-estimated TA which is used to adjust the uplink frame timing relative to the downlink frame timing. Alternatively, the TA pre-compensation information can be the UE's actual location (e.g. UE's GNSS location) or the location of a reference point which is near the UE, which can be used to derive the UE-specific TA based on reported location and satellite's ephemeris data.

The present disclosure provides solutions of TA reporting in NTN. In this solution, the gNB may generate an indication for reporting the TA pre-compensation information based on an elevation angle of a satellite associated with the gNB and transmit the indication to the UE. The UE may determine whether the reporting of the TA pre-compensation information is to be triggered based on the indication.

In this way, the UE may start and stop the reporting of TA pre-compensation information automatically based on criteria defined by network with less signaling overhead. No reporting reconfiguration requirement to enable/disable TA pre-compensation information reporting is needed from the gNB to the UE when the satellite is moving.

Principle and implementations of the present disclosure will be described in detail below with reference to FIG. 2, which shows schematic process of TA reporting in NTN. For the purpose of discussion, the process 200 will be described with reference to FIG. 1. The process 200 may involve the UE 110 and the gNB 120 as illustrated in FIG. 1.

As shown in FIG. 2, the gNB 120 generates 202 an indication for reporting the TA pre-compensation information.

As an option, the indication may comprise an elevation angle threshold of a satellite associated with the gNB 120. The term “elevation angle of a satellite” may be referred to an elevation angle from a reference point in the coverage of the gNB 120 towards the satellite at which the gNB 120 is located. Hereinafter the term “elevation angle” may also be referred to as “elevation angle of a satellite” . Furthermore, the indication may comprise more than one elevation angle threshold of a satellite associated with the gNB 120.

For the earth fixed cells served by a gNB, the elevation angle of the satellite with respect with a UE in the coverage of a cell may be changed with the movement of the satellite. The minimum elevation angle may be the elevation angle being low at the horizon, just after the current cell was created the satellite and just before another cell served by another satellite provides coverage to the area, while the maximum elevation angle of the satellite may be reached when the satellite is right above the cell.

The elevation angle may move over time from the minimum elevation angle to the maximum and then back to the minimum elevation angle. Thus, as another option, the indication may also comprise at least one timestamp threshold associated with the threshold of the elevation angle. Specifically, the at least one timestamp threshold may be referred to as two timestamp thresholds corresponding to the time points at which the elevation angle threshold of the satellite is reached.

For determining the elevation angle threshold, the gNB 120 may determine at least one reference point location associated with earth coverage of the satellite and the ephemeris data of the satellite. Based on the at least one reference point location and the ephemeris data, the gNB 120 may determine respective elevation angles of the satellite along with movement of the satellite.

For a certain elevation angle, the gNB 120 may determine RTTs between the UEs in the coverage of a cell served by the gNB 120 and the gNB 120. Thus, the gNB 120 may determine respective RTTs between UEs and the gNB 120 relative to the respective elevation angles. For example, as shown in FIG. 1, the gNB 120 may determine respective RTTs between UEs 110-1, 110-2 and 110-3 and the gNB 120 relative to the respective elevation angles.

In the scenario shown in FIG. 1, the UE 110-3 can be considered as being located at a nearest end of the coverage of the cell 102, the UE 110-1 can be considered as being located at a farthest end of the coverage of the cell 102 and the UE 110-2 can be considered as being located at the center of the coverage of the cell 102.

For each elevation angle, the gNB 120 may determine the RTTs between the UEs 110-1, 110-2 and 110-3 and the gNB 120. Then the gNB 120 may determine respective RTT variations between the UEs relative to the respective elevation angles.

It is to be understood that the RTT variations between the UEs relative to the respective elevation angles can also depend on other parameters or network configuration such as LEO altitude, a coverage size of the cell, regenerative or transparent architecture as well as gNB or gateway location.

Given the assumption of the LEO with altitude 600km, transparent architecture, the cell coverage with 1000 km diameter and the service link and feeder link has same delay, the RTTs relative to the respective elevation angles and the respective RTT variations can be represented as below.

Table 1: RTT variation (ms) change along with elevation angles

In the Table 1, the RTT Variation between UEs can be considered as a maximum difference between a RTT of a UE and the gNB and a further RTT of a further UE and the gNB among the UEs which may locate in any possible position within the cell’s coverage. For example, when the elevation angle equals to 10, the RTT Variation between UEs can be the RTT difference between the RTT of the UE 110-1 and the gNB and the RTT of the UE 110-3 and the gNB.

The gNB 120 may determine a threshold of the RTT variation from the respective RTT variations relative to the respective elevation angles and determine the elevation angle threshold corresponding to the threshold of the RTT variation. Then the gNB 120 may generate the indication based on the elevation angle threshold.

Reference now made to FIG. 3, which shows an example of criteria for reporting the TA pre-compensation information in NTN according to some example embodiments of the present disclosure. As shown in FIG. 3, for a reference location 321, when the satellite (associated with the gNB 120) moves to the

locations

314 and 315, the

angles

304 and 305 from the reference location towards the satellite reaches a minimum elevation angle and when the satellite moves to the location 312, the angle 301 from the reference location towards the satellite reaches a maximum elevation angle.

As the example shown in FIG. 3, the elevation angle threshold can be the angles 302 and 303 from the reference location towards the satellite when the satellite moves to the

locations

311 and 313. As shown, the elevation angle moves over time from the minimum elevation angle to the maximum elevation angle and then back to the minimum elevation angle. The elevation angle threshold can be used no matter satellite is “moving towards the cell” (for example the elevation angle changes from low to high) or “moving away from the cell” (for example elevation angle changes from high to low again) .

Similarly, for the case where the indication comprises the at least one timestamp corresponding to the elevation angle threshold, the gNB 120 may determine at least one reference point location associated with earth coverage of the satellite and the ephemeris data of the satellite. Based on the at least one reference point location and the ephemeris data, the gNB 120 may determine respective timestamps for the satellite along with movement of the satellite.

For a certain timestamp, the gNB 120 may determine RTTs between the UEs in the coverage of a cell served by the gNB 120 and the gNB 120. As shown in FIG. 1, for each timestamp, the gNB 120 may determine the RTTs between the UEs 110-1, 110-2 and 110-3 and the gNB 120. Then the gNB 120 may determine respective RTT variations between the UEs relative to the respective timestamps.

The gNB 120 may further determine a threshold of the RTT variation from the respective RTT variations and determine at least one timestamp threshold corresponding to the threshold of the RTT variation. Then the gNB 120 may generate the indication based on the at least one timestamp threshold.

Referring back to FIG. 3, the at least one timestamp threshold can be considered as two time points when the elevation angle threshold from the reference point towards the satellite is reached during the movement of the satellite. For example, the first time stamp can be a time point when the satellite moves to the location 311 and a second time stamp can be a time point when the satellite moves to the location 313.

After generating the indication for reporting TA pre-compensation information, the gNB 120 may transmit 204 the indication to UE 110.

In some example embodiments, the gNB 120 may transmit the indication by broadcasting the indication via the system information, such as System Information Block (SIB) .

Alternatively, the gNB 120 may also transmit the indication via a dedicated RRC signalling.

After receiving the indication from the gNB 120, the UE 110 may determine 206 whether the report of TA pre-compensation information from the UE 110 to gNB 120 is to be triggered based on the indication.

In a case where the UE 110 receives the indication comprises an elevation angle threshold of the satellite, the UE 110 may determine the elevation angle of the satellite. If the elevation angle of the satellite with respect with the UE 110 is lower than the elevation angle threshold, the UE 110 may report 208 the TA pre-compensation information to the gNB 120. Otherwise, the UE 110 may stop reporting the TA pre-compensation information.

In some example embodiments, the gNB 120 may transmit the reference point location associated with the satellite and the ephemeris data of the satellite to the UE 110 for the UE 110 to calculate the elevation angle of the satellite.

In some example embodiments, the UE 110 may obtain only the ephemeris data of the satellite from the gNB 120. In this case, the UE 110 may determine the elevation angle of the satellite based on the ephemeris data and its GNSS location.

In a case where the UE 110 receives the indication comprises at least one timestamp, the UE 110 may determine a current time for the UE 110. The current time for the UE 110 may be obtained from the gNB 120. For example, the gNB 120 may transmit time information to the UE 110 via the system information block and UE may obtain current time based on the received time information. The UE 110 may also determine the current time based on the received GNSS information. When the satellite is “moving towards the cell” , the UE 110 may report TA pre-compensation information if the current time is before the first timestamp in the at least one timestamp, while when the satellite is “moving away from the cell” , the UE 110 may report TA pre-compensation information if the current time is after the second timestamp.

The UE 110 may stop TA pre-compensation information reporting automatically if the current time is between two timestamps, i.e., during the time interval where the elevation angle is large enough, there is no need for UEs to report TA pre-compensation information.

The UE 110 may report an TA pre-compensation information to gNB 120 if the criteria based on the received indication, e.g. elevation angle threshold or timestamp threshold, are satisfied.

In some example embodiments, the gNB 120 may indicate a trigger condition for the UE 110 to report the updated TA pre-compensation information. For example, the gNB 120 may define that the UE 110 may trigger the reporting of an updated TA pre-compensation information only if the change of UE estimated TA is larger than a threshold. This trigger condition can be used for the scenario where the UE 110 has already reported the TA pre-compensation information to the gNB 120 based on the received indication, such as elevation angle threshold or timestamp threshold.

FIG. 4 shows a flowchart of an example method 400 of TA reporting in NTN according to some example embodiments of the present disclosure. The method 400 can be implemented at the first device 110 as shown in FIG. 1. For the purpose of discussion, the method 400 will be described with reference to FIG. 1.

At 410, the first device receives, from a second device, an indication for reporting TA pre-compensation information from the first device to the second device. The indication being associated with an elevation angle of a satellite associated with the second device.

In some example embodiments, the indication comprises an elevation angle threshold of the satellite or at least one timestamp threshold corresponding to the elevation angle threshold.

the first device may receive the indication via a system information block or a radio resource control signaling.

At 420, the first device determines the reporting of the TA pre-compensation information at least based on the indication.

In some example embodiments, the first device may determine an elevation angle of the satellite with respect with the first device. If the first device determines that the elevation angle of the satellite with respect with the first device is lower than an elevation angle threshold obtained from the indication, the first device may report the TA pre-compensation information.

In some example embodiments, if the first device determines that the elevation angle of the satellite with respect to the first device exceeds the elevation angle threshold, the first device may stop reporting the TA pre-compensation information.

In some example embodiments, the first device may obtain ephemeris data of the satellite and a reference point location associated with the satellite from the second device and determine the elevation angle of the satellite with respect to the first device based on the ephemeris data and the reference point location.

In some example embodiments, the first device may obtain ephemeris data of the satellite from the second device and determine a location of the first device in the global navigation satellite system. The first device may further determine the elevation angle of the satellite with respect to the first device based on the ephemeris data and the location of the first device.

In some example embodiments, the first device may determine an current time of the first device, wherein the current time is obtained by the first device from the second device via a system information block or from a global navigation satellite system. If the first device determines that the current time is before a first timestamp threshold in at least one timestamp threshold obtained from the indication or after a second timestamp threshold in the at least one timestamp threshold, the first device may report the TA pre-compensation information. The first timestamp threshold is earlier than the second timestamp threshold.

In some example embodiments, if the first device determines that the current time is between the first timestamp threshold and the second timestamp threshold, the first device may stop reporting the TA pre-compensation information.

In some example embodiments, the first device may obtain a TA threshold from the second device. If the first device determines that an TA estimated by first device exceeds the TA threshold, the first device may report the TA pre-compensation information based on the indication.

In some example embodiments, the first device comprises a terminal device and the second device comprises a network device.

FIG. 5 shows a flowchart of an example method 500 of TA reporting in NTN according to some example embodiments of the present disclosure. The method 500 can be implemented at the second device 120 as shown in FIG. 1. For the purpose of discussion, the method 500 will be described with reference to FIG. 1.

At 510, the second device generates an indication for reporting TA pre-compensation information from a first device to the second device based on an elevation angle of a satellite associated with the second device.

In some example embodiments, the second device may determine respective elevation angles of the satellite along with movement of the satellite based on at least one reference point location associated with earth coverage of the satellite and ephemeris data of the satellite and determine respective RTTs between more than one first device and the second device relative to the respective elevation angles. The second device may determine an elevation angle threshold from the respective elevation angles at which a threshold of a RTT variation associated with the respective RTTs is reached. The RTT variation being a difference between a first RTT in the respective RTTs and a second RTT in the respective RTTs. The second device may further generate the indication based on the elevation angle threshold.

In some example embodiments, the second device may determine respective timestamps and corresponding elevation angles of the satellite along with movement of the satellite based on at least one reference point location associated with coverage of the satellite and ephemeris data of the satellite. The second device may determine respective RTTs between more than one first device and the second device relative to the respective elevation angles and at least one timestamp threshold from the respective timestamps at which a threshold of a RTT variation associated with the respective RTTs is reached, the RTT variation being a difference between a first RTT in the respective RTTs and a second RTT in the respective RTTs. The second device may further generate the indication based on the at least one timestamp threshold.

At 520, the second device transmits the indication to the first device.

In some example embodiments, the second device may transmit the indication via a system information block or a radio resource control signaling.

In some example embodiments, an apparatus capable of performing the method 400 (for example, implemented at the UE 110) may comprise means for performing the respective steps of the method 400. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some example embodiments, the apparatus comprises means for receiving, from a second device, an indication for reporting TA pre-compensation information from a first device to the second device, the indication being associated with an elevation angle of a satellite associated with the second device, and means for determining the reporting of the TA pre-compensation information at least based on the indication.

In some example embodiments, an apparatus capable of performing the method 500 (for example, implemented at the gNB 120) may comprise means for performing the respective steps of the method 500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some example embodiments, the apparatus comprises means for generating an indication for reporting TA pre-compensation information from a first device to a second device based on an elevation angle of a satellite associated with the second device and means for transmitting the indication to the first device.

FIG. 6 is a simplified block diagram of a device 600 that is suitable for implementing embodiments of the present disclosure. The device 600 may be provided to implement the communication device, for example the UE 110 and the gNB 120 as shown in FIG. 1. As shown, the device 600 includes one or more processors 610, one or more memories 640 coupled to the processor 610, and one or more transmitters and/or receivers (TX/RX) 640 coupled to the processor 610.

The TX/RX 640 is for bidirectional communications. The TX/RX 640 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements.

The processor 610 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 600 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

The memory 620 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 624, an electrically programmable read only memory (EPROM) , a flash memory, a hard disk, a compact disc (CD) , a digital video disk (DVD) , and other magnetic storage and/or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 622 and other volatile memories that will not last in the power-down duration.

A computer program 630 includes computer executable instructions that are executed by the associated processor 610. The program 630 may be stored in the ROM 620. The processor 610 may perform any suitable actions and processing by loading the program 630 into the RAM 620.

The embodiments of the present disclosure may be implemented by means of the program 630 so that the device 600 may perform any process of the disclosure as discussed with reference to FIGs. 2 to 5. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some embodiments, the program 630 may be tangibly contained in a computer readable medium which may be included in the device 600 (such as in the memory 620) or other storage devices that are accessible by the device 600. The device 600 may load the program 630 from the computer readable medium to the RAM 622 for execution. The computer readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. FIG. 7 shows an example of the computer readable medium 700 in form of CD or DVD. The computer readable medium has the program 630 stored thereon.

Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, device, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the methods 500-600 as described above with reference to FIGs. 5-6. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing device, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of the present disclosure, the computer program codes or related data may be carried by any suitable carrier to enable the device, device or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in languages specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A first device comprising:

at least one processor; and

at least one memory including computer program codes;

the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device at least to:

receive, from a second device, an indication for reporting Timing Advance (TA) pre-compensation information from the first device to the second device, the indication being associated with an elevation angle of a satellite associated with the second device; and

determine the reporting of the TA pre-compensation information at least based on the indication.
The first device of Claim 1, wherein the indication comprises at least one of the following:

an elevation angle threshold of the satellite, or

at least one timestamp threshold corresponding to the elevation angle threshold.
The first device of Claim 1, wherein the first device is caused to receive the indication by:

receiving the indication via at least one of the following:

a system information block, or

a radio resource control signaling.
The first device of Claim 1, wherein the first device is caused to determine the reporting of the TA pre-compensation information by:

determining an elevation angle of the satellite with respect to the first device; and

in accordance with a determination that the elevation angle of the satellite with respect to the first device is lower than an elevation angle threshold obtained from the indication, reporting the TA pre-compensation information.
The first device of Claim 4, wherein the first device is further caused to:

in accordance with a determination that the elevation angle of the satellite with respect to the first device exceeds the elevation angle threshold, stop reporting the TA pre-compensation information.
The first device of Claim 4, wherein the first device is caused to determine the elevation angle of the satellite with respect to the first device by:

obtaining ephemeris data of the satellite and a reference point location associated with the satellite, from the second device; and

determining the elevation angle of the satellite with respect to the first device based on the ephemeris data and the reference point location.
The first device of Claim 4, wherein the first device is caused to determine the elevation angle of the satellite with respect to the first device by:

obtaining ephemeris data of the satellite from the second device;

determining a location of the first device in the global navigation satellite system; and

determining the elevation angle of the satellite with respect to the first device based on the ephemeris data and the location of the first device.
The first device of Claim 1, wherein the first device is caused to determine the reporting of the TA pre-compensation information by:

determining a current time for the first device, wherein the current time is obtained by the first device from the second device via a system information block or from a global navigation satellite system; and

in accordance with a determination that the current time is before a first timestamp threshold in at least one timestamp threshold obtained from the indication or after a second timestamp threshold in the at least one timestamp threshold, reporting the TA pre-compensation information, the first timestamp threshold being earlier than the second timestamp threshold.
The first device of Claim 8, wherein the first device is further caused to:

in accordance with a determination that the current time is between the first timestamp threshold and the second timestamp threshold, stop reporting the TA pre-compensation information.
The first device of Claim 1, wherein the first device is further caused to:

obtain a TA threshold from the second device; and

in accordance with a determination that an TA estimated by the first device exceeds the TA threshold, report the TA pre-compensation information based on the indication.
The first device of Claim 1, wherein the first device comprises a terminal device and the second device comprises a network device.
A second device comprising:

at least one processor; and

at least one memory including computer program codes;

the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device at least to:

generate an indication for reporting Timing Advance (TA) pre-compensation information from a first device to the second device based on an elevation angle of a satellite associated with the second device; and

transmit the indication to the first device.
The second device of Claim 12, wherein the indication comprises at least one of the following:

an elevation angle threshold of the satellite, or

at least one timestamp threshold corresponding to the elevation angle threshold.
The second device of Claim 12, wherein the second device is caused to generate the indication by:

determining respective elevation angles of the satellite along with movement of the satellite based on at least one reference point location associated with earth coverage of the satellite and ephemeris data of the satellite;

determining respective Round-Trip Times, RTTs, between more than one first device and the second device relative to the respective elevation angles;

determining an elevation angle threshold from the respective elevation angles at which a threshold of a RTT variation associated with the respective RTTs is reached, the RTT variation being a difference between a first RTT in the respective RTTs and a second RTT in the respective RTTs; and

generating the indication based on the elevation angle threshold.
The second device of Claim 12, wherein the second device is caused to generate the indication by:

determining respective timestamps and corresponding elevation angles of the satellite along with movement of the satellite based on at least one reference point location associated with coverage of the satellite and ephemeris data of the satellite;

determining respective Round-Trip Times, RTTs, between more than one first device and the second device relative to the respective elevation angles;

determining at least one timestamp threshold from the respective timestamps at which a threshold of a RTT variation associated with the respective RTTs is reached, the RTT variation being a difference between a first RTT in the respective RTTs and a second RTT in the respective RTTs; and

generating the indication based on the at least one timestamp threshold.
The second device of Claim 12, wherein the second device is caused to transmit the indication by:

transmitting the indication via at least one of the following:

a system information block, or

a radio resource control signaling.
The second device of Claim 12, wherein the first device comprises a terminal device and the second device comprises a network device.
A method comprising:

receiving, from a second device, an indication for reporting Timing Advance (TA) pre-compensation information from a first device to the second device, the indication being associated with an elevation angle of a satellite associated with the second device; and

determining the reporting of the TA pre-compensation information at least based on the indication.
The method of Claim 18, wherein the indication comprises at least one of the following:

an elevation angle threshold of the satellite, or

at least one timestamp threshold corresponding to the elevation angle threshold.
The method of Claim 18, wherein receiving the indication comprises:

receiving the indication via at least one of the following:

a system information block, or

a radio resource control signaling.
The method of Claim 18, wherein determining the reporting of the TA pre-compensation information comprises:

determining an elevation angle of the satellite with respect to the first device; and

in accordance with a determination that the elevation angle of the satellite with respect to the first device is lower than an elevation angle threshold obtained from the indication, reporting the TA pre-compensation information.
The method of Claim 21, further comprising:

in accordance with a determination that the elevation angle of the satellite with respect to the first device exceeds the elevation angle threshold, stopping reporting the TA pre-compensation information.
The method of Claim 21, wherein determining the elevation angle of the satellite with respect to the first device comprises:

obtaining ephemeris data of the satellite and a reference point location associated with the satellite from the second device; and

determining the elevation angle of the satellite with respect to the first device based on the ephemeris data and the reference point location.
The method of Claim 21, wherein determining the elevation angle of the satellite with respect to the first device comprises:

obtaining ephemeris data of the satellite from the second device;

determining a location of the first device in the global navigation satellite system; and

determining the elevation angle of the satellite with respect to the first device based on the ephemeris data and the location of the first device.
The method of Claim 18, wherein determining the reporting of the TA pre-compensation information comprises:

determining a current time for the first device, wherein the current time is obtained by the first device from the second device via a system information block or from a global navigation satellite system; and

in accordance with a determination that the current time is before a first timestamp threshold in at least one timestamp threshold obtained from the indication or after a second timestamp threshold in the at least one timestamp thresholds, reporting the TA pre-compensation information, the first timestamp threshold being earlier than the second timestamp threshold.
The method of Claim 25, further comprising:

in accordance with a determination that the current time is between the first timestamp threshold and the second timestamp threshold, stopping reporting the TA pre-compensation information.
The method of Claim 18, further comprising:

obtaining a TA threshold from the second device; and

in accordance with a determination that an TA estimated by the first device exceeds the TA threshold, reporting the TA pre-compensation information based on the indication.
The method of Claim 18, wherein the first device comprises a terminal device and the second device comprises a network device.
A method comprising:

generating an indication for reporting Timing Advance (TA) pre-compensation information from a first device to a second device based on an elevation angle of a satellite associated with the second device; and

transmitting the indication to the first device.
The method of Claim 29, wherein the indication comprises at least one of the following:

an elevation angle threshold of the satellite, or

at least one timestamp threshold corresponding to the elevation angle threshold.
The method of Claim 29, wherein generating the indication comprises:

determining respective elevation angles of the satellite along with movement of the satellite based on at least one reference point location associated with earth coverage of the satellite and ephemeris data of the satellite;

determining respective Round-Trip Times, RTTs, between more than one first device and the second device relative to the respective elevation angles;

determining an elevation angle threshold from the respective elevation angles at which a threshold of a variation associated with the respective RTTs is reached, the variation being a difference between a first RTT in the respective RTTs and a second RTT in the respective RTTs; and

generating the indication based on the elevation angle threshold.
The method of Claim 29, wherein generating the indication comprises:

determining respective timestamps and corresponding elevation angles of the satellite along with movement of the satellite based on at least one reference point location associated with coverage of the satellite and ephemeris data of the satellite;

determining respective Round-Trip Times, RTTs, between more than one first device and the second device relative to the respective elevation angles;

determining at least one timestamp threshold from the respective timestamps at which a threshold of a variation associated with the respective RTTs is reached, the variation being a difference between a first RTT in the respective RTTs and a second RTT in the respective RTTs; and

generating the indication based on the at least one timestamp threshold.
The method of Claim 29, wherein transmitting the indication comprises:

transmitting the indication via at least one of the following:

a system information block, or

a radio resource control signaling.
The method of Claim 29, wherein the first device comprises a terminal device and the second device comprises a network device.
An apparatus comprising:

means for receiving, from a second device, an indication for reporting Timing Advance (TA) pre-compensation information from the first device to the second device, the indication being associated with an elevation angle of a satellite associated with the second device; and

means for determining the reporting of the TA pre-compensation information at least based on the indication.
An apparatus comprising:

means for generating an indication for reporting Timing Advance (TA) pre-compensation information from a first device to the second device based on an elevation angle of a satellite associated with the second device; and

means for transmitting the indication to the first device.
A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method of any of claims 18-28, or any of claims 29-34.