Signaling for terminal device measurement during aerospace device switching

Abstract

A method comprises determining, at a network device, a radio condition change of an aerospace device (e.g. a satellite in a non-terrestrial network (NTN)) associated with a cell for which a terminal i

Description

FIELD

[0001] Example embodiments of the present disclosure generally relate to the field of communications, and in particular, to a terminal device, a network device, methods, apparatuses and a computer readable storage medium for signaling for terminal device measurement during aerospace device switching. BACKGROUND

[0002] The feasibility of using 5G NR standards to support non-terrestrial networks (NTN) is being studied. In an NTN system, 5G base stations (gNB) or gNB functionality are deployed on board satellites or relayed by gNBs in a transparent way to provide communication coverage over a very large area. There are different types of satellite orbits such as Low Earth Orbit (LEO) for NTN communication. It is needed to make some research on how a user equipment (UE) and network (NW) should behave in case of aerospace device switching such as satellite switching. The same problem may need to be studied in high speed airplane switching, unmanned aerial system switching, or other use cases. The UE can also be some other device, such as a relay device. SUMMARY

[0003] In general, example embodiments of the present disclosure provide a solution for signaling for terminal device measurement during aerospace device switching.

[0004] In a first aspect, there is provided a terminal device. The terminal device comprises at least one processor and at least one memory storing instructions. When executed by the at least one processor, cause the terminal device at least to: receive an indication of a radio condition change of aerospace device associated with a cell for which the terminal device is performing at least one measurement; and reset, based on the indication, the at least one measurement for the cell.

[0005] In a second aspect, there is provided a network device. The network device comprises at least one processor and at least one memory storing instructions. When executed by the at least one processor, cause the network device at least to: determine a radio condition change of aerospace device associated with a cell for which a terminal device is performing at least one measurement; and transmit, to the terminal device, an indication of the change.

[0006] In a third aspect, there is provided a method. The method comprises: receiving, at a terminal device, an indication of a radio condition change of aerospace device associated with a cell for which the terminal device is performing at least one measurement; and resetting, based on the indication, the at least one measurement for the cell.

[0007] In a fourth aspect, there is provided a method. The method comprises: determining, at a network device, a radio condition change of aerospace device associated with a cell for which a terminal device is performing at least one measurement; and transmitting, to the terminal device, an indication of the change.

[0008] In a fifth aspect, there is provided an apparatus. The apparatus comprises: means for receiving, at a terminal device, an indication of a radio condition change of aerospace device associated with a cell for which the terminal device is performing at least one measurement; and means for resetting, based on the indication, the at least one measurement for the cell.

[0009] In a sixth aspect, there is provided an apparatus. The apparatus comprises: means for determining, at a network device, a radio condition change of aerospace device associated with a cell for which a terminal device is performing at least one measurement; and means for transmitting, to the terminal device, an indication of the change.

[0010] In a seventh aspect, there is provided a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method in the third, and the fourth aspects.

[0011] In an eighth aspect, there is provided a computer program. The computer program comprises instructions, which, when executed by an apparatus, cause the apparatus to perform at least the method in the third, and the fourth aspects.

[0012] In a ninth aspect, there is provided a terminal device. The terminal device comprises: receiving circuitry configured to receive an indication of a radio condition change of aerospace device associated with a cell for which the terminal device is performing at least one measurement; and resetting circuitry configured to reset, based on the indication, the at least one measurement for the cell.

[0013] In a tenth aspect, there is provided a network device. The network device comprises: determining circuitry configured to determine a radio condition change of aerospace device associated with a cell for which a terminal device is performing at least one measurement; and transmitting circuitry configured to transmit, to the terminal device, an indication of the change.

[0014] It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Some example embodiments will now be described with reference to the accompanying drawings, in which:

[0016] FIG. 1A illustrates an example communication system in which some example embodiments of the present disclosure may be implemented;

[0017] FIG. IB illustrates an example of aerospace device switching such as satellite switching where a network device does not change associated with some example embodiments of the present disclosure;

[0018] FIG. 2 illustrates an example of process flow for aerospace device switching (such as, satellite switching) in accordance with some example embodiments of the present disclosure;

[0019] FIG. 3 illustrates an example of process flow measurement reset in the terminal device in accordance with some example embodiments of the present disclosure;

[0020] FIG. 4 illustrates an example of a method implemented at a terminal device in accordance with some example embodiments of the present disclosure;

[0021] FIG. 5 illustrates an example of a method implemented at a network device in accordance with some example embodiments of the present disclosure;

[0022] FIG. 6 illustrates a simplified block diagram of a device that is suitable for implementing some example embodiments of the present disclosure; and 3

[0023] FIG. 7 illustrates a block diagram of an example of a computer readable medium in accordance with some example embodiments of the present disclosure.

[0024] Throughout the drawings, the same or similar reference numerals represent the same or similar elements. DETAILED DESCRIPTION

[0025] The principles 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.

[0026] 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 the ordinary skills in the art to which this disclosure belongs.

[0027] 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 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.

[0028] 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 one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0029] 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 4 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 herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0030] 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(s) 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 (for example, firmware) for operation, but the software may not be present when it is not needed for operation.

[0031] 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.

[0032] As used herein, the term “communication network” refers to a network following any suitable communication standards, such as 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 fourth generation (4G), 4.5G, the future fifth generation (5G) 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.

[0033] 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), an NR NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, an Integrated and Access Backhaul (IAB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network devices such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the applied terminology and technology.

[0034] 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), 6 USB dongles, smart devices, wireless customer-premises equipment (CPE), an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (for example, remote surgery), an industrial device and applications (for example, 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. In the following description, the terms “terminal device”, “communication device”, “terminal” may be used interchangeably.

[0035] The feasibility of using 5G new radio (NR) standards to support non-terrestrial networks has been studied during the third generation partnership project (3GPP) releases 15 and 16. In December 2019, 3GPP RAN plenary meeting approved the normative specification work item for NTN in release 17. In the work item, the user equipment’s (UE’s) supporting NTN are assumed to have global navigation satellite system (GNSS) capability. In an NTN system, 5G base stations (gNB) or gNB functionality are deployed on board satellites or transparently relayed by the gNB to provide communication coverage over a very large area that may be otherwise unreachable by cellular networks. Such functionality can be used to connect Internet of Things (loT) devices globally as well as provide personal communication in remote areas and in disaster relief.

[0036] FIG. 1A illustrates an example communication system in which some example embodiments of the present disclosure may be implemented. In the communication system 100, a data network 107 sends data to or receives data from a network device 105. The network device 105 can be a gNB, an eNB, or base station of other radio access technology (RAT). The network device 105 sends data to, and / or receives data from an aerospace device 103 such as a satellite or other unmanned aerial systems. The aerospace device 103 can make beam footprints such as beam footprint 111 on the earth, with beam forming, and provides service to a terminal device 101 such as a UE with a service link 109. There can also be a gateway at the position of the network device 105, for generating wireless signal transmitting to the aerospace device 103, or for receiving signal from the aerospace device 103.

[0037] Different types of satellite orbits are studied for NR access including low earth orbit (LEO) satellites which orbit at approximately 600 km above the earth. During the Rel-16 study item, the typical beam footprint size for an LEO satellite was assumed to be between 100-1000 km radius. So one LEO satellite can cover a very large area on the earth which may include multiple countries. Since the aerospace device 103 flies so fast in orbit, there can be aerospace device switching such as satellite switching for the terminal device 101 on the earth in the service.

[0038] In Rel-18, the topic of unchanged physical cell identifier (PCI) was introduced or is being considered for introduction in 3GPP, to reduce the signaling overhead and simplify radio resource control (RRC) procedures for the terminal device 101. The working principle is that after the aerospace device switching such as satellite switching, the serving gNB (on the ground) does not change and, therefore, the cell configuration or the majority of the cell configuration can be kept without changing the PCI, frequency, and other cell configuration parameters, such as servingCellconfigCommon. Then, the aerospace device switching such as satellite switching is almost transparent for the terminal device 101, which is not required to perform L3 mobility such as handover procedure, and the terminal device 101 does not need to update the security key. The conditions for the mechanism to work are in the following. NTN cells must be deployed as quasi-earth fixed cells (EFC) since the cell coverage’s area should not change. The network (NW) should indicate the terminal device 101 how and / or when to perform downlink (DL) and uplink (UL) synchronization after aerospace device switching such as satellite switching. The network device 105 would accept an interruption gap for the terminal device 101 to detect the new timing and adapt to the new timing. The network device 105 needs to have means to avoid radio link failure (RLF) during this interruption gap, such as after the “old” cell disappears and before the “new” cell takes over.

[0039] In Rel-18 the focus is on transparent architecture and the most obvious case is when the cells are provided by the same gNB, such as the same cell with the fixed PCI is provided by the same gNB, so only the satellite node is changed. However, theoretically, this could also work with different gNB and potentially even for the regenerative case.

[0040] FIG. IB illustrates an example of aerospace device switching such as satellite switching where a network device does not change associated with some example embodiments of the present disclosure. Specifically, the PCI is kept unchanged in a transparent-based EFC deployment. In 120, there are a terminal device 101, a gNB and gateway 121, a first satellite 123, and a second satellite 125. The terminal device 101 such as a UE is the same with the terminal device 101 in FIG. 1 A, the gNB and gateway 121 can be an implementation of the network device 105, and the first satellite 123, and the second satellite 125 can be implementations of the aerospace device 103 in FIG. 1A. The first satellite 123 can be the first aerospace device, and the second satellite 125 can be the second aerospace device.

[0041] The following steps will take place during the aerospace device switching such as satellite switching. Step 1: the terminal device 101, which is stationary, is being served by the first satellite 123 or an old satellite in an old cell 131 with link 129, and served by the gNB and gateway 121 with link 127. Step 2: as the first satellite 123 moves away from the terminal device 101 and the second satellite 125 or a new satellite gets closer, the gNB and gateway 121 indicates when the aerospace device switching such as satellite switching will occur and how to perform re-synchronization to a new cell 137. Step 3: once the second satellite 125 takes over the new cell 137, the terminal device 101 performs DL / UL synchronization operations for re-connection.

[0042] Even though the terminal device 101 is being served by the second satellite 125 or the new satellite, it does not change the gNB and gateway 121 or the serving gNB, so the terminal device 101 can keep the cell configuration. The first satellite 123 and the second satellite 125 are configured with the same PCI, same UE context, and same protocol stack, such as including one or more of synchronization signal and broadcast block (SSB) generation, coding and / or decoding, modulation and / or demodulation, same CORESET configuration, and switch routing. However, from the terminal device 101 ’s reference, the first satellite 123 and the second satellite 125 introduce different frequency offset, such as different Doppler shift due to different moving directions 139 and 141 relative to the terminal device 101, and timing drifts due to such as different transmission delays to the terminal device 101. Note that no specific agreements on how the terminal device 101 and the gNB and gateway 121 should behave in case of aerospace device switching such as satellite switching have been made as part of the 3GPP discussions yet.

[0043] The aerospace device switching such as satellite switching can be broken down in two additional scenarios: i) hard aerospace device switching such as hard satellite switching and ii) soft aerospace device switching such as soft satellite switching. The latter considers a certain cell overlapping between the NTN cell radiated by the first satellite 123 and the second satellite 125, while the former considers no overlapping between the old cell 131 and the new cell 137. The terminal device 101 can consider certain interruption time to precompensate the frequency and timing of the new cell 137. For the soft aerospace device switching such as soft satellite switching it is assumed that first satellite 123 and second satellite 125 are transmitting SSBs at the same time, potentially with the same PCI, but with different time / frequency offset, thereby allowing the terminal device 101 to gracefully switch to the new 137 of the incoming second satellite 125 in theory.

[0044] The current 3GPP discussions related to aerospace device switching such as satellite switching and unchanged PCI have been captured in chairman minutes but not many details have been agreed with respect to the specific operational steps.

[0045] In meeting RAN2#121-bis-e, the following agreements were made for the topic. 1. In quasi-earth fixed (QEF) cell case, for hard satellite switch (the old cell 131 and the new cell 137 do not overlap) in the same SSB frequency and same gNB without key change, aerospace device switching such as satellite switching without PCI changing or not requiring L3 mobility is supported, unless major technical issues are identified by RANI. As usual, RAN2 will aim at minimizing the specification impact so that it fits in Rel-18. 2. Remove the part in brackets “ as usual RAN2 will aim at minimizing the specification impact so that it fits in Rel-18” in the LS to RANI. The action to RANI will also ask for feedback for the hard satellite switch, not only in the soft satellite switch case, such as the action to RANI is to see if there are any major technical issues as in the agreement.

[0046] In meeting RAN2#122, the following agreements were made for the topic. 1. T-service or a time indication of the end of coverage of the cell for unchanged PCI mobility in SIB19 can also be interpreted by Rel-18 UE in connected mode to know that a satellite change or feeder link change happens. In hard switch unchanged PCI scenario or no handover, the terminal device 101 needs to know the time the terminal device 101 attempts to re-synchronize. It is needed for further studying whether a new t-start or a time indication when the satellite associated with the new cell 137 becomes available for the unchanged PCI mobility, or a t-gap or a time duration during which the cell is unavailable for the unchanged PCI mobility is needed or whether t-Service can be reused with no other information element (IE), if the gap is very short or zero.

[0047] This means that, at least hard aerospace device switching such as satellite switching with unchanged PCI and without layer 3 (L3) mobility was agreed to be supported. However, no explicit details have been decided so far.

[0048] For mobility enhancement in Rel-18 NR NTN, in quasi-earth fixed cell case, RAN2 has discussed unchanged PCI scenario, including hard aerospace device switching such as 10 satellite switching (non-overlapping satellite coverage at switching time) and soft aerospace device switching such as soft satellite switching (overlapping satellite coverage at switching time).

[0049] RAN2 has agreed that, in quasi-earth fixed cell case, for hard satellite switch in the same SSB frequency and same gNB (no key change), aerospace device switching such as satellite switching without PCI changing (not requiring L3 mobility) is supported, unless major technical issues are identified by RANI. RAN2 understands that the standard impact includes that the UE may be notified to re-acquire DL / UL synchronization with the serving cell after the aerospace device switching such as satellite switching.

[0050] RAN2 understands that the feasibility of soft aerospace device switching such as satellite switching without PCI change (not requiring L3 mobility) is more relevant to RANI aspects, and would like to check its feasibility with RANI. RAN2 requests RANI to take into account the above agreement on hard aerospace device switching such as hard satellite switching without PCI change and provide feedback if RANI identifies any major technical issues, and also provide feedback on the feasibility to support soft aerospace device switching such as soft satellite switching without PCI change.

[0051] During RAN1#113 the topic was discussed shortly, and RANI provided an LS response to RAN2. The question is for hard aerospace device switching such as hard satellite switching without PCI change, whether RANI identifies any major technical issues. The reply from RAN 1 is, RANI discussed the resynchronization of UE when hard switching, given that new common timing advance (TA), K mac, ephemeris, and cell-specific K-offset are applied during resynchronization to the new satellite. From RANI perspective, no feasibility issue is identified for hard aerospace device switching such as satellite switching without PCI change.

[0052] In some embodiments, in the unchanged PCI scenario, the aerospace device switching such as satellite switching occurs transparently to the terminal device 101 such as the UE. That means that the terminal device 101 switches from the first satellite 123 such as a source satellite access node to the second satellite 125 such as a target satellite access node without performing L3 mobility and without changing the network device 121 such as serving gNB. The topic is currently discussed in 3GPP and considers two scenarios: hard aerospace device switching such as satellite switching and soft aerospace device switching such as satellite switching. The initial agreements consider at least the hard aerospace device switching such as satellite switching, or no overlapping time between old and new cells.

[0053] In some embodiments, the hard aerospace device switching such as satellite switching with unchanged PCI is a scenario that aims to make the cell switching as transparent as possible for the terminal device 101 and that involves reducing the service interruption as much as possible so the terminal device 101 can resume transmission (TX) / reception (RX) seamlessly by making the satellite switch happening similar to a “ fl ip of a switch” , where all UEs will adapt to the new cell conditions with minimum interruption. There will be some interruption due to UEs potentially losing connection and having to reconnect, such as new cell access failure, while others may need interruption time to retune radio front-end hardware, such as pre-compensation of timing and Doppler offsets.

[0054] In some embodiments, the soft aerospace device switching such as satellite switching with unchanged PCI is a scenario that aims to make the cell switching as transparent as possible for the terminal device 101 and that involves a certain coverage overlapping between the first satellite 123 such as the serving satellite and the second satellite 125 such as the incoming satellite. The gNB 121 creates a live replica of the cell identity, that is routed through both satellites. The overlapping period before aerospace device switching such as satellite switching can allow UEs to attempt re-synchronizing to the same cell with a more time-spread series of events that may distribute the load and ensure that some UEs may be able to do IDLE mode mobility to the new serving satellite with the same PCI.

[0055] In some embodiments, besides the serving cell, there can be one or more neighbor cells for the terminal device 101. One of the challenges when performing a change of satellite while maintaining the same PCI is that any UE such as the terminal device 101 doing measurements within the system, such as either serving cell measurements or neighbor cell measurements may be confused from the sudden change of signal propagation conditions, signal timing, Doppler offset, etc. This can potentially cause the UE to make erroneous measurements and potentially trigger actions from the network side that may not be needed.

[0056] Examples of cases where the terminal device 101 can perform avoidable measurements, erroneous measurements or measurements that can lead to signaling overhead. The terminal device 101 measures neighbor cells right before t-service. The terminal device 101 may trigger a measurement report if it observes similar or better signal 12 conditions for neighbor cells close to the location of the terminal device 101. If the satellite switch is closed, the terminal device 101 could relax or pause these measurements since signal conditions for the surrounding cells will change after the satellite switch. The terminal device 101 conducts cell measurements during hard-satellite switch interruption time. The terminal device 101 may attempt to perform cell measurements during the interruption gap for radio link monitoring. This may lead to an unnecessary increase in power consumption in the terminal device 101.

[0057] In some embodiments, the terminal device 101 conducts L3 measurements once the new cell is available. Cell measurements are filtered at Layer 1 and Layer 3. Such filtering uses past samples to average out short-term signal fades and other signal impairments. During and after the satellite switch, the UE might consider past samples from the previous satellite that will lead to erroneous measurements. The terminal device 101 conducts neighbor cell measurements during overlapping period in a soft-aerospace device switching such as soft-satellite switching. The terminal device 101 may attempt to perform neighbor cell measurements during the overlapping period.

[0058] FIG. 2 illustrates an example of process flow for aerospace device switching (such as satellite switching) in accordance with some example embodiments of the present disclosure. In the process flow 200, at 210, the network device 105 determines a radio condition change of an aerospace device associated with a cell for which a terminal device is performing at least one measurement. The network device 105 sends (213) to the terminal device 101, an indication 213 of the radio condition change. After receiving the indication 213, the terminal device 101 resets the at least one measurement for the cell based on the indication 213.

[0059] In some embodiments, there can be a serving cell and / or one or multiple neighbor cells for the terminal device 101. In the event that the cell is a serving cell of the terminal device 101, the indication comprises first time information such as “t” for resetting the at least one measurement for the serving cell. This way, the terminal device 101 can get the first time information for aerospace device switching such as satellite switching in the serving cell, and capture timing for correct measurements of the new radio condition in the serving cell, avoiding unnecessary measurement reporting and potential mobility events and reducing power consumption.

[0060] Additionally or alternatively, if the cell is a neighbor cell of the terminal device 101, the indication comprises second time information such as “t2” for resetting the at least one measurement for the neighbor cell. This way, the terminal device 101 can get the second time information for aerospace device switching such as satellite switching in the neighbor cell, and capture timing for correct measurements of the new radio condition in the neighbor cell, avoid unnecessary measurement reporting and potential mobility events and reduce power consumption.

[0061] As an example, the first time information is the same with the second time information, in case such as the serving cell and the neighbor cell are generated by the same aerospace device such as the same satellite. This way, the indication of radio condition change and resetting the measurement can be simplified, to reduce power consumption in the terminal device 101.

[0062] In some example implementations, one or both of the first time information and the second time information can indicate various types of time information. For example, the first time information, the second time information, or both may include an absolute time point. Additionally or alternatively, the first time information, the second time information, or both can contain a time duration. Additionally or alternatively, the first time information, the second time information, or both may include a time point relative to at least one reference time point such as the t-Service. This way, the first time information and / or the second time information can be implemented flexibly.

[0063] In some embodiments, one of both of the first time information, and the second time information is based on a time indication of the end of coverage of the cell for aerospace device switching without L3 mobility, such as unchanged physical cell ID (PCI) mobility such as “t-service”. Additionally or alternatively, the first time information, the second time information, or both is based on a time indication when the satellite associated to the cell becomes available for the unchanged PCI mobility such as “t-start”. Additionally or alternatively, the first time information, the second time information, or both is based on a time duration during which the cell is unavailable for the unchanged PCI mobility such as “t-gap”. In details,. “T-service” can indicate the time when the terminal device 101 lefts the coverage of the current serving cell or the current neighbor cell. “T-start” can indicate the time when the terminal device 101 comes into the coverage of the new serving cell or the new neighbor cell. “T-gap” can indicate the time when the terminal device 101 is in the gap between the current serving cell and the new serving cell, or in the gap between the current neighbor cell and the new neighbor cell. The skilled in the art can understand that the first time information and the second time information can be implemented in other formats. This way, the time of aerospace device switching such as satellite switching can be indicated flexibly for both the serving cell and the neighbor cell.

[0064] In some example senatios, there can be a plurality of neighbor cells for the terminal device 101. The second time information is configured for the plurality of neighbor cells of the terminal device 101, wherein the neighbor cell is one of the plurality of neighbor cells. This way, the second time information can be transmitted to the terminal device 101 in one message, to reduce message payload. Alternatively, the second time information is configured separately for the different neighbor cell of the terminal device 101, to improve flexibility for the second time information.

[0065] The first time information or the second time information can be transmitted in various possible manners. For example, the first time information can be broadcast as part of the system information of the serving cell, such as common serving cell configuration parameters. Additionally or alternatively, the second time information may be part of the system information of at least one of the serving cell or the neighbor cell, such as system information block 19 (SIB 19) for NR NTN. Additionally or alternatively, the first time information, the second time information, or both may be overwritten by dedicated signaling. This way, the first time information, and the second time information can be transmitted to the terminal device 101 reliably and can be overwritten flexibly.

[0066] In some example situations, the cell can be a serving cell of the terminal device 101. In these situations, the indication may comprise first time information for resetting the at least one measurement for the serving cell, and the terminal device 101 is further caused to determine the first time information as second time information for resetting one or more measurements for one or more neighbor cells of the terminal device 101. This way, the measurement can be simplified in case such as the serving cell and the neighbor cell is generated by the same satellite.

[0067] The serving cell and the neighbor cell can be generated by the same satellite. The terminal device 101 may determine the first time information as the second time information in the following scheme. Based on receiving an indication that the first time information applies to the at least one neighbor cell of the terminal device 101, the terminal device 101 determines the first time information as the second time information in the absence of the second time information. This way, the second time information can be saved, to save some signaling payload.

[0068] In some examples, the measurement in the terminal device 101 can be reset in the radio condition change such as aerospace device switching such as satellite switching. For instance, in resetting the at least one measurement, the terminal device 101 may determine at least one sample obtained after the radio condition change of aerospace device as invalid for the at least one measurement. Alternatively or additionally, the terminal device 101 can start to perform a set of measurements based on the radio conditions after the change. Alternatively or additionally, the terminal device 101 may reset at least one measurement sample for the at least one measurement. Alternatively or additionally, the terminal device 101 may change measurement conditions based on the radio conditions after the change. As an addition or an altenative, the terminal device 101 may change at least one measurement filter coefficient for the at least one measurement. As an addition or an altenative, the terminal device 101 can change the number of samples required for the at least one measurement. This way, the interference can be avoided between the samples in different radio conditions before the changing and after the change, thus ensuring correct UE behavior, avoiding potential mobility events and reducing UE’s power consumption.

[0069] In some embodiments, there can be one or more cases that lead to radio condition changing for the terminal device 101. The change in the radio conditions of the cell can be caused by hard aerospace device switching such as hard satellite switching from the first satellite 123 providing the cell 131 to the second satellite 125 providing the cell 137. Additionally or alternatively, the change in the radio conditions of the cell can be caused by soft aerospace device switching such as soft satellite switching from the first satellite 123 to the second satellite 125. Additionally or alternatively, the change in the radio conditions of the cell can be caused by a change of a beam of a satellite providing the cell. Additionally or alternatively, the change in the radio conditions of the cell can be caused by a change in transmitting power of the satellite providing the cell. Additionally or alternatively, the change in the radio conditions of the cell can be caused by a change of a beam direction of the satellite providing the cell. Additionally or alternatively, the change in the radio conditions of the cell can be caused by a change in a beamwidth of a beam of the satellite providing the cell. The skill in the art can understand that the change in the radio conditions of the cell can be caused by other cases. This way, the radio condition changing and 16 measurement resetting can be applied to several cases, to make the terminal device 101 reliable communication.

[0070] In some embodiments, the network device 105 can discard measurement reports for cells that are received from the terminal device 101 shortly before the switching time, to avoid measurement reports with error.

[0071] In some embodiments, the present disclosure can be summarized in the following. It is proposed to create awareness of the potential sudden change of radio conditions of a given cell that is being used as a candidate for measurements. The origin for such a change of radio conditions may be a soft or hard satellite switch routing the same cell with unchanged PCI, but may be triggered by other conditions as well for the general applicability of the application. The change could also occur for the same cell with changed PCI. The awareness may be provided for the current serving cell or a candidate neighbor cell. The awareness may be created by indicating a specific time by which the terminal device 101 should consider measurements as “potentially broken”.

[0072] In some embodiments, there may be the following exemplified cases. In the first case, the terminal device 101 in RRCIDLE or RRCINACTIVE is performing measurements towards its serving cell and when the configured time “t” is reached, the terminal device 101 will stop or relax considering new samples as valid for current measurements, to stop new samples from “polluting” existing measurements, while at the same time starting a new set of measurements with new radio timing conditions, such as with new SSB timing, new Doppler offset, etc. The terminal device 101 resets the filters to perform new “clean” measurements.

[0073] In the second case, the terminal device 101 is performing measurements on neighbors, whereas the terminal device 101 is configured with measurement events that are similar to type Bl or B2. A configured time “t2” for one neighbor is reached, at which the terminal device 101 will either reset the measurement samples for the configured neighbor, change the measurement conditions with new radio parameters, or change the measurement filter coefficients to account for abrupt change or changes in the radio conditions for the neighbor cell.

[0074] In some embodiments, the target scenario is EFC deployments with hard and soft aerospace device switching such as soft satellite switching. The advantage of the embodiments can be that by controlling or resetting the measurements, the terminal device 17 101 captures correct measurements of the new radio conditions. This ensures correct behavior of the terminal device 101, avoids unnecessary measurements reporting and potential mobility events, and reduces power consumption of the terminal device 101.

[0075] In some embodiments, the detailed implementation is illustrated in the following. FIG. 3 illustrates an example of process flow measurement reset in the terminal device in accordance with some example embodiments of the present disclosure. While doing measurements for the serving cell and / or neighboring cells at 310, the terminal device 101 is checking if the time “t” is reached for the serving cell at 320. The time “t” can also correspond to a time window, where the serving cell is unavailable. When the time “t” is reached, or the time window has passed, the terminal device 101 resets the measurements for the serving cell and adapts to new radio conditions at 320. At the same time, the terminal device 101 is checking if the time “t2” is reached for the neighbor cell at 340. The time “t2” can also correspond to a time window, where the neighbor cell is unavailable. When the time “t2” is reached, or the time window has passed, the terminal device 101 resets the measurements for the neighbor cell and adapts to new radio conditions. This way, the terminal device 101 can reset measurement when the radio condition change in the serving cell or the neighbor cell, to avoid unnecessary measurement reporting and potential mobility events and reduce the power consumption of the terminal device 101.

[0076] In some embodiments, the times “f ’ and “t2” can relate to an absolute point in time, a time duration, or a relative time with respect to another time, such as t-Service or the time indication of the end of coverage of the cell for unchanged PCI mobility. Times “t” and “t2” can also relate to the considered framework in 3GPP for unchanged PCI mobility, such as t-Service, t-Start as the time indication when the satellite associated with the cell becomes available for the unchanged PCI mobility, or t-Gap as the time duration during which the cell is unavailable for the unchanged PCI mobility. More specifically, time values “t” and “t2” can be the same as any of t-service, t-start, t-gap, or the combination thereof. In other possible scenarios, those time values correspond to t-service, t-start, t-gap. This way, the radio condition change can be indicated to the terminal device 101 flexibly.

[0077] In some embodiments, the same “t2” is given for a list of neighbor cells such as percell list. Alternatively, a different “t2” such as array of “t2” could be given to the terminal device 101 indicating to which neighbor cells apply. This way, the second time information such as “t2” can be used flexibly in multiple cases. In case of “t2” absence, the terminal device 101 can implicitly assume “t” as “t2” for all cells, assuming surrounding cells will switch at a similar time as the serving cell. Similarly, the UE could read a flag that indicated the explicit use of all the “t2” as “t” This way, the signaling payload can be saved, or the indication can be more reliable in error reception of “t2”.

[0078] In some embodiments, the time “t” can be broadcast as part of the system information of the serving cell, such as common serving cell configuration parameters, while the time “t2” could be included as part of the serving cell’s system information or the neighbor cell’s system information, such as SIB 19 for NR NTN. This way, the time “t” or “t2” can be transmitted to the terminal device 101 reliably. The time “t” or “t2” can be overwritten by dedicated signaling, such as a reconfiguration message for UEs in connected mode. This way, the time “t” or “t2” can be overwritten can be overwritten flexibly.

[0079] In some embodiments can also achieve dynamically changing the number of samples required for cell measurements. This way, the interference in the radio condition changing can be reduced. In some embodiments, the network device 105 can discard measurement reports for cells that are received shortly before the switching time, to avoid measurement report with error. In some embodiments, the time “t” and “t2” also can be used to reset of reconfigure the measurements in the case satellite beams change behavior, like changing power, shifting the beam direction disruptively or changing the beamwidth. This way, the measurement resetting can be adaptive to multiple radio condition changing cases.

[0080] FIG. 4 illustrates an example of a method implemented at a terminal device 101 in accordance with some example embodiments of the present disclosure. In method 400, at 410, the terminal device 101 receives an indication of a radio condition change of aerospace device associated with a cell for which the terminal device 101 is performing at least one measurement. At 420, based on the indication, the terminal device 101 resets the at least one measurement for the cell.

[0081] In some embodiments, in the event that the cell is a serving cell of the terminal device 101, the indication comprises first time information for resetting the at least one measurement for the serving cell; or in the event that the cell is a neighbor cell of the terminal device 101, the indication comprises second time information for resetting the at least one measurement for the neighbor cell.

[0082] In some embodiments, the first time information is the same with the second time information. In some embodiments, at least one of the first time information or the second time information indicates at least one of the following: an absolute time point; a time duration; or a time point relative to at least one reference time point.

[0083] In some embodiments, at least one of the first time information or the second time information is based on at least one of the following: a time indication of the end of coverage of the cell for aerospace device switching without L3 mobility; a time indication when the aerospace device associated to the cell becomes available for the unchanged PCI mobility; or a time duration during which the cell is unavailable for the unchanged PCI mobility.

[0084] In some embodiments, the second time information is configured for a plurality of neighbor cells of the terminal device 101, wherein the neighbor cell is one of the plurality of neighbor cells; or the second time information is configured separately for the neighbor cell of the terminal device 101.

[0085] In some embodiments, the method comprises at least one of the following: the first time information is broadcast as part of system information of the serving cell; the second time information is part of system information of at least one of the serving cell or the neighbor cell; or at least one of the first time information or the second time information is overwritten by dedicated signaling.

[0086] In some embodiments, the cell is a serving cell of the terminal device 101, the indication comprises first time information for resetting the at least one measurement for the serving cell, and the terminal device 101 is further caused to: determine the first time information as second time information for resetting at least one measurement for at least one neighbor cell of the terminal device 101.

[0087] In some embodiments, the terminal device 101 is caused to determine the first time information as the second time information by: based on receiving an indication that the first time information is applicable to the at least one neighbor cell of the terminal device 101, determining the first time information as the second time information in the absence of the second time information.

[0088] In some embodiments, wherein the terminal device 101 is caused to reset the at least one measurement by at least one of the following: determining at least one sample obtained after the radio condition change of aerospace device as invalid for the at least one measurement; starting to perform a set of measurements based on the radio conditions after 20 the change; resetting at least one measurement sample for the at least one measurement; changing measurement conditions based on the radio conditions after the change; changing at least one measurement filter coefficient for the at least one measurement; or changing the number of samples required for the at least one measurement.

[0089] In some embodiments, the change in the radio conditions of the cell is caused by at least one of the following: hard aerospace device switching such as hard satellite switching from a first aerospace device providing the cell to a second aerospace device providing the cell; soft aerospace device switching such as soft satellite switching from the first aerospace device to the second aerospace device; a change of a beam of a satellite providing the cell; a change in transmitting power of the satellite providing the cell; a change of a beam direction of the satellite providing the cell; or a change in a beamwidth of a beam of the satellite providing the cell.

[0090] FIG. 5 illustrates an example of a method implemented at a network device in accordance with some example embodiments of the present disclosure. In the method 500, at 510, the network device 105 determines a radio condition change of aerospace device associated with a cell for which a terminal device 101 is performing at least one measurement. At 520, the network device 105 transmits to the terminal device 101, an indication of the radio condition change.

[0091] In some embodiments, in the event that the cell is a serving cell of the terminal device 101, the indication comprises first time information for resetting the at least one measurement for the serving cell; or in the event that the cell is a neighbor cell of the terminal device 101, the indication comprises second time information for resetting the at least one measurement for the neighbor cell.

[0092] In some embodiments, the first time information is the same with the second time information. In some embodiments, at least one of the first time information or the second time information indicates at least one of the following: an absolute time point; a time duration; or a time point relative to at least one reference time point.

[0093] In some embodiments, at least one of the first time information or the second time information is based on at least one of the following: a time indication of end of coverage of the cell for aerospace device switching without L3 mobility; a time indication when the aerospace device associated to the cell becomes available for the unchanged PCI mobility; or a time duration during which the cell is unavailable defined for the unchanged PCI mobility.

[0094] In some embodiments, the second time information is configured for a plurality of neighbor cells of the terminal device, wherein the neighbor cell is one of the plurality of neighbor cells; or the second time information is configured separately for the neighbor cell of the terminal device.

[0095] In some embodiments, at least one of the following: the first time information is broadcast as part of system information of at least one of the serving cell or the serving cell; the second time information is part of system information of the neighbor cell; at least one of the first time information or the second time information is overwritten by dedicated signaling.

[0096] In some embodiments, the cell is a serving cell of the terminal device 101, the indication comprises first time information for resetting the at least one measurement for the serving cell, and the network device 105 is further caused to: transmit, to the terminal device 101, an indication that the first time information is applicable to at least one neighbor cell of the terminal device 101.

[0097] In some embodiments, the network device 105 is further caused to: discard at least one measurement report received from the terminal device 101 during a predetermined duration prior to the change in the radio conditions. In some embodiments, the change in the radio conditions of the cell is caused by at least one of the following: hard aerospace device switching such as hard satellite switching from a first aerospace device providing the cell to a second aerospace device providing the cell; soft aerospace device switching such as soft satellite switching from the first aerospace device to the second aerospace device; a change of a beam of a satellite providing the cell; a change in transmitting power of the satellite providing the cell; a change of a beam direction of the satellite providing the cell; or a change in a beamwidth of a beam of the satellite providing the cell.

[0098] In some embodiments, an apparatus capable of performing the method 400 (for example, the terminal device 101) 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.

[0099] In some embodiments, the apparatus comprises means for receiving an indication of a radio condition change of aerospace device associated with a cell for which the terminal 22 device 101 is performing at least one measurement; and means for resetting, based on the indication, the at least one measurement for the cell.

[00100] In some embodiments, in the event that the cell is a serving cell of the terminal device 101, the indication comprises first time information for resetting the at least one measurement for the serving cell; or in the event that the cell is a neighbor cell of the terminal device 101, the indication comprises second time information for resetting the at least one measurement for the neighbor cell.

[00101] In some embodiments, the first time information is the same with the second time information. In some embodiments, at least one of the first time information or the second time information indicates at least one of the following: an absolute time point; a time duration; or a time point relative to at least one reference time point.

[00102] In some embodiments, at least one of the first time information or the second time information is based on at least one of the following: a time indication of end of coverage of the cell for aerospace device switching without L3 mobility; a time indication when the aerospace device associated to the cell becomes available for the unchanged PCI mobility; or a time duration during which the cell is unavailable for the unchanged PCI mobility.

[00103] In some embodiments, the second time information is configured for a plurality of neighbor cells of the terminal device 101, wherein the neighbor cell is one of the plurality of neighbor cells; or the second time information is configured separately for the neighbor cell of the terminal device 101.

[00104] In some embodiments, the first time information is broadcast as part of system information of the serving cell; the second time information is part of system information of at least one of the serving cell or the neighbor cell; or at least one of the first time information or the second time information is overwritten by dedicated signaling.

[00105] In some embodiments, the cell is a serving cell of the terminal device 101, the indication comprises first time information for resetting the at least one measurement for the serving cell, and the apparatus further comprises means for determining the first time information as second time information for resetting at least one measurement for at least one neighbor cell of the terminal device 101.

[00106] In some embodiments, the means for determining the first time information as second time information comprises: means for based on receiving an indication that the first time information is applicable to the at least one neighbor cell of the terminal device 101, determining the first time information as the second time information in the absence of the second time information.

[00107] In some embodiments, the means for resetting the at least one measurement comprises at least one of the following: means for determining at least one sample obtained after the radio condition change of aerospace device as invalid for the at least one measurement; means for starting to perform a set of measurements based on the radio conditions after the change; means for resetting at least one measurement sample for the at least one measurement; means for changing measurement conditions based on the radio conditions after the change; means for changing at least one measurement filter coefficient for the at least one measurement; or means for changing the number of samples required for the at least one measurement.

[00108] In some embodiments, the change in the radio conditions of the cell is caused by at least one of the following: hard aerospace device switching such as hard satellite switching from a first aerospace device providing the cell to a second aerospace device providing the cell; soft aerospace device switching such as soft satellite switching from the first aerospace device to the second aerospace device; a change of a beam of a satellite providing the cell; a change in transmitting power of the satellite providing the cell; a change of a beam direction of the satellite providing the cell; or a change in a beamwidth of a beam of the satellite providing the cell.

[00109] In some embodiments, an apparatus capable of performing the method 500 (for example, the network device 105) 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.

[00110] In some embodiments, the apparatus comprises: means for determining a radio condition change of aerospace device associated with a cell for which a terminal device 101 is performing at least one measurement; and means for transmitting, to the terminal device 101, an indication of the change.

[00111] In some embodiments, in the event that the cell is a serving cell of the terminal device 101, the indication comprises first time information for resetting the at least one measurement for the serving cell; or in the event that the cell is a neighbor cell of the terminal device 101, the indication comprises second time information for resetting the at least one 24 measurement for the neighbor cell.

[00112] In some embodiments, the first time information is the same with the second time information. In some embodiments, at least one of the first time information or the second time information indicates at least one of the following: an absolute time point; a time duration; or at least one time point relative to a reference time point.

[00113] In some embodiments, at least one of the first time information or the second time information is based on at least one of the following: a time indication of end of coverage of the cell for unchanged physical cell ID (PCI) mobility; a time indication when the aerospace device associated to the cell becomes available for the unchanged PCI mobility; or a time duration during which the cell is unavailable defined for aerospace device switching without L3 mobility.

[00114] In some embodiments, the second time information is configured for a plurality of neighbor cells of the terminal device 101, wherein the neighbor cell is one of the plurality of neighbor cells; or the second time information is configured separately for the neighbor cell of the terminal device 101.

[00115] In some embodiments, at least one of the following: the first time information is broadcast as part of system information of the serving cell; the second time information is part of system information of at least one of the serving cell or the neighbor cell; at least one of the first time information or the second time information is overwritten by dedicated signaling.

[00116] In some embodiments, the cell is a serving cell of the terminal device 101, the indication comprises first time information for resetting the at least one measurement for the serving cell, and the apparatus further comprises means for transmitting to the terminal device 101, an indication that the first time information is applicable to at least one neighbor cell of the terminal device 101.

[00117] In some embodiments, the apparatus further comprises means for discarding at least one measurement report received from the terminal device 101 during a predetermined duration prior to the change in the radio conditions. In some embodiments, the change in the radio conditions of the cell is caused by at least one of the following: hard aerospace device switching such as hard satellite switching from a first aerospace device providing the cell to a second aerospace device providing the cell; soft aerospace device switching such as soft satellite switching from the first aerospace device to the second aerospace device; a 25 change of a beam of a satellite providing the cell; a change in transmitting power of the satellite providing the cell; a change of a beam direction of the satellite providing the cell; or a change in a beamwidth of a beam of the satellite providing the cell.

[00118] FIG. 6 illustrates a simplified block diagram of a device 600 that is suitable for implementing some example embodiments of the present disclosure. The device 600 may be provided to implement a communication device, for example, the terminal device 101, or the network device 105 as shown in FIG. 1 A, or FIG. 3. As shown, the device 600 includes one or more processors 610, one or more memories 620 coupled to the processor 610, and one or more communication modules 640 coupled to the processor 610.

[00119] The communication module 640 is for bidirectional communications. The communication module 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.

[00120] 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.

[00121] Memory 620 may include one or more non-volatile memories and one or more volatile memories. Examples of 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 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.

[00122] A computer program 630 includes computer-executable instructions that are executed by the associated processor 610. The program 730 may be stored in the ROM 624. The processor 610 may perform any suitable actions and processing by loading the program 630 into the RAM 622.

[00123] 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 26 with reference to FIGS. 1A to 5. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[00124] In some example 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.

[00125] FIG. 7 illustrates a block diagram of an example of a computer readable medium 700 in accordance with some example embodiments of the present disclosure. The computer readable medium 700 has the program 630 stored thereon. It is noted that although the computer readable medium 700 is depicted in the form of CD or DVD in FIG. 8, the computer readable medium 700 may be in any other form suitable for carrying or holding the program 630.

[00126] 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, apparatus, 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.

[00127] 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 method 400, or 500 as described above with reference to FIG. 4 or 5. 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.

[00128] 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 apparatus, 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.

[00129] 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, apparatus, or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

[00130] 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, apparatus, 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. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e g., RAM vs. ROM).

[00131] 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 5 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.

[00132] 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 10 or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A terminal device comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to:receive an indication of a radio condition change of aerospace device associated with a cell for which the terminal device is performing at least one measurement; andreset, based on the indication, the at least one measurement for the cell.

2. The terminal device of claim 1, wherein:in the event that the cell is a serving cell of the terminal device, the indication comprises first time information for resetting the at least one measurement for the serving cell; orin the event that the cell is a neighbor cell of the terminal device, the indication comprises second time information for resetting the at least one measurement for the neighbor cell.

3. The terminal device of claim 2, wherein:the first time information is the same with the second time information.

4. The terminal device of claim 2 or 3, wherein at least one of the first time information or the second time information indicates at least one of the following:an absolute time point;a time duration; ora time point relative to at least one reference time point.

5. The terminal device of any one of claims 2-4, wherein at least one of the first time information or the second time information is based on at least one of the following:a time indication of end of coverage of the cell for aerospace device switching without L3 mobility;a time indication when the aerospace device associated to the cell becomes available for the unchanged PCI mobility; ora time duration during which the cell is unavailable for the unchanged PCI mobility.

6. The terminal device of any of claims 2-5, wherein:the second time information is configured for a plurality of neighbor cells of the terminal device, wherein the neighbor cell is one of the plurality of neighbor cells; orthe second time information is configured separately for the neighbor cell of the terminal device.

7. The terminal device of any of claims 2-6, wherein at least one of the following:the first time information is broadcast as part of system information of the serving cell;the second time information is part of system information of at least one of the serving cell or the neighbor cell; orat least one of the first time information or the second time information is overwritten by dedicated signaling.

8. The terminal device of claim 1, wherein the cell is a serving cell of the terminal device, the indication comprises first time information for resetting the at least one measurement for the serving cell, and the terminal device is further caused to:determine the first time information as second time information for resetting at least one measurement for at least one neighbor cell of the terminal device.

9. The terminal device of claim 8, wherein the terminal device is caused to determine the first time information as the second time information by:based on receiving an indication that the first time information is applicable to the at least one neighbor cell of the terminal device, determining the first time information as the second time information in the absence of the second time information.

10. The terminal device of any of claims 1-9, wherein the terminal device is caused to reset the at least one measurement by at least one of the following:determining at least one sample obtained after the radio condition change of aerospace device as invalid for the at least one measurement;starting to perform a set of measurements based on the radio conditions after the change;resetting at least one measurement sample for the at least one measurement;changing measurement conditions based on the radio conditions after the change;changing at least one measurement filter coefficient for the at least one measurement; orchanging the number of samples required for the at least one measurement.

11. The terminal device of any of claims 1-10, wherein the change in the radio conditions of the cell is caused by at least one of the following:hard aerospace device switching from a first aerospace device providing the cell to a second aerospace device providing the cell;soft aerospace device switching from the first aerospace device to the second aerospace device;a change of a beam of an aerospace device providing the cell;a change in transmitting power of the aerospace device providing the cell;a change of a beam direction of the aerospace device providing the cell; ora change in a beam width of a beam of the aerospace device providing the cell.

12. A network device comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the network device at least to:determine a radio condition change of aerospace device associated with a cell for which a terminal device is performing at least one measurement; andtransmit, to the terminal device, an indication of the change.

13. The network device of claim 12, wherein:in the event that the cell is a serving cell of the terminal device, the indication comprises first time information for resetting the at least one measurement for the serving cell; orin the event that the cell is a neighbor cell of the terminal device, the indication comprises second time information for resetting the at least one measurement for the neighbor cell.

14. The terminal device of claim 13, wherein:the first time information is the same with the second time information.

15. The network device of claim 13 or 14, wherein at least one of the first time information or the second time information indicates at least one of the following:an absolute time point;a time duration; ora time point relative to at least one reference time point.

16. The network device of claim 13-15, wherein at least one of the first time information or the second time information is based on at least one of the following:a time indication of end of coverage of the cell for aerospace device switching without L3 mobility;a time indication when the aerospace device associated to the cell becomes available for the unchanged PCI mobility; ora time duration during which the cell is unavailable defined for the unchanged PCI mobility.

17. The network device of any of claims 13-16, wherein:the second time information is configured for a plurality of neighbor cells of the terminal device, wherein the neighbor cell is one of the plurality of neighbor cells; orthe second time information is configured separately for the neighbor cell of the terminal device.

18. The network device of any of claims 13-17, wherein at least one of the following:the first time information is broadcast as part of system information of the serving cell;the second time information is part of system information of at least one of the serving cell or the neighbor cell;at least one of the first time information or the second time information is overwritten by dedicated signaling.

19. The network device of claim 12, wherein the cell is a serving cell of the terminal device, the indication comprises first time information for resetting the at least one measurement for the serving cell, and the network device is further caused to:transmit, to the terminal device, an indication that the first time information is applicable to at least one neighbor cell of the terminal device.

20. The network device of any of claims 12-19, wherein the network device is further caused to:discard at least one measurement report received from the terminal device during a predetermined duration prior to the change in the radio conditions.

21. The network device of any of claims 12-20, wherein the change in the radio conditions of the cell is caused by at least one of the following:hard aerospace device switching from a first aerospace device providing the cell to a second aerospace device providing the cell;soft aerospace device switching from the first aerospace device to the second aerospace device;a change of a beam of an aerospace device providing the cell;a change in transmitting power of the aerospace device providing the cell;a change of a beam direction of the aerospace device providing the cell; ora change in a beamwidth of a beam of the aerospace device providing the cell.

22. A method comprising:receiving, at a terminal device, an indication of a radio condition change of aerospace device associated with a cell for which the terminal device is performing at least one measurement; andresetting, based on the indication, the at least one measurement for the cell.

23. A method comprising:determining, at a network device, a radio condition change of aerospace device associated with a cell for which a terminal device is performing at least one measurement; andtransmitting, to the terminal device, an indication of the change.

24. An apparatus comprising:means for receiving, at a terminal device, an indication of a radio condition change of aerospace device associated with a cell for which the terminal device is performing at least one measurement; andmeans for resetting, based on the indication, the at least one measurement for the cell.

25. An apparatus comprising:means for determining, at a network device, a radio condition change of aerospace device associated with a cell for which a terminal device is performing at least one measurement; andmeans for transmitting, to the terminal device, an indication of the change.

26. A non-transitory computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least the method of claim 22 or 23.

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