Measurement prior to radio link failure

Abstract

The application relates to devices and components including apparatuses, systems and methods for performing measurements prior to radio link failure. In an example, a condition is detected by a UE before a point in time at which a non-terrestrial network (NTN) node will cease providing service to the UE. The condition may be a timing-based condition related to, for example, t-service, a location-based condition related to, for example, a reference location, a coverage hole, and / or a timer condition. The UE may perform radio resource management (RRM) measurements before the point in time based on the condition to attempt to measure neighboring cells.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority to patent application No. PCT / CN2022 / 111166, “Measurement Before Radio Link Failure,” filed on August 9, 2022, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present application relates generally to wireless communication systems, and in particular to measurements prior to radio link failure. Background Art

[0004] The 3rd Generation Partnership Project (3GPP) Technical Specifications (TS) define standards for wireless networks. These TSs describe various aspects related to user equipment making measurements on neighboring cells for mobility purposes. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 A network environment according to some embodiments is illustrated.

[0006] Figure 2 A timing diagram according to some embodiments is illustrated.

[0007] Figure 3 An example of non-terrestrial network (NTN) coverage according to some embodiments is illustrated.

[0008] Figure 4 Overlay scenarios according to some embodiments are illustrated.

[0009] Figure 5 Timing-based radio resource management (RRM) measurements according to some embodiments are illustrated.

[0010] Figure 6 Location-based RRM measurements according to some embodiments are illustrated.

[0011] Figure 7 RRM measurements based on network coverage holes according to some embodiments are illustrated.

[0012] Figure 8 Timer-based RRM measurements according to some embodiments are illustrated.

[0013] Fig. 9 An example of an operational flow / algorithm structure implemented to manage the performance of RRM measurements according to some embodiments is illustrated.

[0014] Fig.10 User equipment according to some embodiments is illustrated.

[0015] Fig.11 A base station according to some embodiments is illustrated. DETAILED DESCRIPTION

[0016] The following specific embodiments refer to the accompanying drawings. The same reference numerals may be used to identify the same or similar elements in different drawings. In the following description, specific details, such as specific structures, architectures, interfaces and technologies are described for the purpose of illustration rather than limitation, so as to provide a thorough understanding of various aspects of various embodiments. However, it is obvious to those skilled in the art who benefit from the present disclosure that various aspects of various embodiments can be practiced in other examples that deviate from these specific details. In some instances, descriptions of well-known devices, circuits and methods are omitted so as not to obscure the descriptions of various embodiments due to unnecessary details. For the purposes of this document, the phrases "A / B" and "A or B" refer to (A), (B) or (A and B); and the phrase "based on A" refers to "based at least in part on A", for example, it can be "based only on A" or it can be "based in part on A".

[0017] Embodiments of the present disclosure relate to managing the execution of measurements (such as radio resource management (RRM) measurements) before radio link failure (RLF). In an example, a serving cell of a user equipment (UE) is provided by a non-terrestrial network (NTN) node, such as provided by a satellite in the case of satellite-based communications (although non-satellite NTN is also possible). Before the point in time when the NTN node will stop providing service to the UE, the UE can determine that a set of conditions are met to perform RRM measurements. Therefore, the UE performs RRM measurements before the point in time based on the conditions to attempt to measure a neighboring cell. The neighboring cell can be a terrestrial network (TN) cell or another NTN cell. The point in time can be determined based on timing information and / or location information received from the network. The network can also configure the UE with information about the cell that needs to be measured. By doing so, the UE can avoid attempting to perform RRM measurements when not needed, thereby improving its overall power consumption. These and other features are further described below.

[0018] The following is a glossary of terms that may be used in this disclosure.

[0019] As used herein, the term "circuit" refers to a part of or including a hardware component configured to provide the described functionality. A hardware component may include an electronic circuit, a logic circuit, a processor (shared, dedicated or group) or a memory (shared, dedicated or group), an application specific integrated circuit (ASIC), a field programmable device (FPD) (e.g., a field programmable gate array (FPGA), a programmable logic device (PLD), a complex PLD (CPLD), a high capacity PLD (HCPLD), a structured ASIC or a programmable system on chip (SoC)) or a digital signal processor (DSP). In some embodiments, a circuit may execute one or more software or firmware programs to provide at least some of the functionality. The term "circuit" may also refer to a combination of one or more hardware elements (or a combination of circuits used in an electrical or electronic system) and the program code for executing the functionality of a program code. In these embodiments, the combination of hardware elements and program code may be referred to as a circuit of a specific type.

[0020] As used herein, the term "processor circuit" refers to, is part of, or includes a circuit capable of sequentially and automatically performing a series of arithmetic or logical operations or recording, storing, or transferring digital data. The term "processor circuit" may refer to an application processor, a baseband processor, a central processing unit (CPU), a graphics processing unit, a single-core processor, a dual-core processor, a triple-core processor, a quad-core processor, or any other device capable of executing or otherwise operating computer-executable instructions (such as program code, software modules, and / or functional processes).

[0021] As used herein, the term "interface circuit" refers to, is a part of, or includes a circuit that enables information exchange between two or more components or devices. The term "interface circuit" may refer to one or more hardware interfaces, such as a bus, an I / O interface, a peripheral component interface, and a network interface card.

[0022] As used herein, the term "user equipment" or "UE" refers to a device with radio communication capabilities that can allow a user to access network resources in a communication network. The term "user equipment" or "UE" may be considered synonymous with the following and may be referred to as a client, mobile phone, mobile device, mobile terminal, user terminal, mobile unit, mobile station, mobile user, subscriber, user, remote station, access agent, user agent, receiver, radio equipment, reconfigurable radio equipment or reconfigurable mobile device. In addition, the term "user equipment" or "UE" may include any type of wireless / wired device or any computing device that includes a wireless communication interface.

[0023] As used herein, the term "computer system" refers to any type of interconnected electronic devices, computer devices, or components thereof. Additionally, the term "computer system" or "system" may refer to various components of a computer that are communicatively coupled to each other. Furthermore, the term "computer system" or "system" may refer to multiple computer devices or multiple computing systems that are communicatively coupled to each other and configured to share computing resources or networked resources.

[0024] As used herein, the term "resource" refers to a physical or virtual device, a physical or virtual component within a computing environment, or a physical or virtual component within a specific device, such as a computer device, a mechanical device, a memory space, a processor / CPU time, a processor / CPU usage rate, a processor and accelerator load, a hardware time or usage rate, a power supply, an input / output operation, a port or a network socket, a channel / link allocation, a throughput, a memory usage rate, a storage, a network, a database, and an application or a workload unit. "Hardware resources" may refer to computing, storage, or network resources provided by physical hardware elements. "Virtualized resources" may refer to computing, storage, or network resources provided by a virtualized infrastructure to an application, device, or system. The term "network resources" or "communication resources" may refer to resources that can be accessed by a computer device / system via a communication network. The term "system resources" may refer to any kind of shared entity that provides a service, and may include computing resources or network resources. System resources may be considered as a set of coherent functions, network data objects, or services that can be accessed through a server, wherein such system resources reside on a single host or multiple hosts and can be clearly identified.

[0025] As used herein, the term "channel" refers to any tangible or intangible transmission medium for communicating data or data streams. The term "channel" may be synonymous or equivalent to "communication channel", "data communication channel", "transmission channel", "data transmission channel", "access channel", "data access channel", "link", "data link", "carrier", "radio frequency carrier" or any other similar term representing a path or medium through which data is communicated. Additionally, as used herein, the term "link" refers to a connection made between two devices for sending and receiving information.

[0026] As used herein, the terms "instantiate," "instantiate," and the like refer to the creation of an instance. "Instance" also refers to a specific occurrence of an object, which may occur, for example, during the execution of program code.

[0027] The term "connected" may mean that two or more elements at a common communication protocol layer have an established signaling relationship with each other through a communication channel, link, interface, or reference point.

[0028] As used herein, the term "network element" refers to physical or virtualized equipment or infrastructure used to provide wired or wireless communication network services. The term "network element" may be considered synonymous with or referred to as a networked computer, networking hardware, network equipment, network node, or virtualized network function.

[0029] The term "information element" refers to a structural element that contains one or more fields. The term "field" refers to the individual contents of an information element, or a data element that contains the contents. An information element may include one or more additional information elements.

[0030] Figure 1 A network environment 100 is illustrated according to some embodiments. The network environment 100 may include a user equipment (UE) 104 communicatively coupled to a serving base station 108 of a radio access network (RAN). The serving base station 108 may provide a serving cell 112.

[0031] UE 104 and base station 108 can communicate over an air interface compatible with 3GPP TSs, such as those defining Long Term Evolution (LTE) systems, fifth generation (5G) New Radio (NR) systems, or later systems. Base station 108 can provide user plane and control plane protocol terminations to UE 104 through serving cell 112.

[0032] The network environment 100 may also include neighboring base stations 116 that provide neighboring cells 120 .

[0033] In some instances, the connection that UE 104 has with serving base station 108 may degrade. This may be based on the relative movement between UE 104 and serving base station 108. For example, UE 104 may move away from serving base station 108, or serving base station 108 may move away from UE 104. The latter scenario may occur if serving base station 108 is, for example, a satellite of a non-terrestrial network (NTN).

[0034] To avoid radio link failure (RLF) based on the degraded connection, the UE 104 may attempt to reestablish a radio resource control (RRC) connection with the neighboring cell 120. To this end, the UE 104 may perform RRM measurements as part of cell search, cell selection, cell reselection, handover, etc. The RRM measurements may include different types of measurements indicating channel quality as part of intra-frequency measurements, inter-frequency measurements, and / or inter-RAT measurements, such as reference signal received power (RSRP) measurements, narrowband RSRP (NRSRP), etc.

[0035] In some embodiments, UE 104 may be a narrowband Internet of Things (NB-IoT) UE, which may have relatively long latency for RRC re-establishment.

[0036] Figure 2 An overview of RLF and RRC re-establishment 200 according to some embodiments is illustrated. A relatively long delay in RRC re-establishment of the NB-IoT UE may be between reference point A and reference point D, which may be due to the NB-IoT UE not supporting mobility in the RRC connected state (e.g., no measurement report, no handover, etc.) or due to a relatively long time (e.g., hundreds of milliseconds) to perform cell selection after RLF declaration.

[0037] The relatively long latency is related to various operations / configurations associated with pre-Release 17 (R17) NB-IoT UEs that are compatible with LTE. For example, pre-R17 NB-IoT has no provision for neighbor frequency / cell information, and the UE will need to determine the frequencies / cells to measure on its own. In another example, the NB-IoT UE will not perform neighbor cell measurements or will not provide measurement reports. In yet another example, the NB-IoT UE will not perform a handover, but instead the NB-IoT UE will perform an RRC re-establishment instead.

[0038] Typically, a UE such as a NB-IoT UE compatible with LTE will only perform connection state measurements when two conditions are met. The first condition may correspond to a timer (T3xx / T326) running, and the second condition may correspond to a serving cell quality threshold.

[0039] Timer T3xx (T326) can be triggered due to a transition to a connected state and the relaxed monitoring criteria are not met, or due to a rapid change in the quality of the serving cell when neighCellMeasCriteria is configured. The rapid change can be determined using t-MeasureDeltaP and s-MeasureDeltaP. MeasureDeltaP is the duration for which the UE performs RRM when neighborCellMeasCriteria (channel quality change) is configured. s-MeasureDeltaP is a threshold configuration for changes in the quality of the serving cell (neighCellMeasCriteria). With regard to the quality of the serving cell (the second condition), the threshold configuration for the quality of the serving cell can be determined based on s-MeasureIntra for intra-frequency measurements or s-MeasureInter for inter-frequency measurements. These conditions can be defined as follows (for example, as a supplement to 3GPP TS136.304, V17.2.0 (2022-10)):

[0040] 5.5.x Measurements in NB-IoT

[0041] When transitioning to RRC_CONNECTED mode, the UE shall:

[0042] l>If neighCellMeasCriteria exists in SystemlnformationBlockType3-

[0043] In NB:

[0044] 2> NRSR Ref Set to the most recent result of the serving cell measurement used for cell selection / reselection evaluation;

[0045] 2> If the relaxed monitoring criteria defined in TS 36.304[4] are not met:

[0046] 3> Start T3XX with value t-MeasureDeltaP;

[0047] While in RRC_CONNECTED mode, after performing measurements, the UE shall:

[0048] 1> Use the NRSRP measurement for the measured carrier and the corresponding

[0049] nrs-PowerOffsetNonAnchor of the measured carrier;

[0050] 1>If neighCellMeasCriteria exists in SystemlnformationBlockType3-

[0051] In NB:

[0052] 2>If (NRSRP Ref –(NRSRP–PowerOffsetNonAnchor))>s-

[0053] MeasureDeltaP:

[0054] 3>Set NRSRP Ref =(NRSRP – nrs-PowerOffsetNonAnchor); 3> Start or restart T3XX with the value t-MeasureDeltaP;

[0055] 1>If neighCellMeasCriteria does not exist in SystemlnformationBlockType3-

[0056] NB; or

[0057] 1> If T3XX is running:

[0058] 2> If (NRSRP – nrs-PowerOffsetNonAnchor) < s-Measurelntra, perform intra-frequency measurements as defined in TS 36.133

[161] .

[0059] 2> If (NRSRP – nrs-PowerOffsetNonAnchor) < s-Measurelnter,

[0060] perform inter-frequency measurements as defined in TS 36.133

[16] .

[0061] When served by a terrestrial network (TN) node, the above conditions and variations can be defined for NB-IoT UEs. However, serving by a non-terrestrial network (NTN) node requires considering other factors, as further described in the following figures.

[0062] Figure 3 An example of non-terrestrial network (NTN) coverage 300 according to some embodiments is illustrated. Network 310 can be accessible to a UE via a network node 320 supporting multiple cells. Each cell corresponds to a coverage area within which the NTN coverage 300 is available. Due to different factors including movement of the network node 320, redirection of the beams providing the cells, movement of the UE 304 to an area not covered by the network coverage 300, etc., the network coverage 300 can be discontinuous across the coverage areas. For example, the network coverage 300 can be available in a first cell during a certain time interval and not available in a second cell during the same time interval. During different time intervals, the network coverage 300 can be no longer available in the first cell and available in the second cell.

[0063] In the example, network 310 can implement a specific set of radio access technologies (RATs), such as but not limited to LTE and / or different generations of 3GPP networks. Network 310 can also be a terrestrial network, in which case the network node 320 can be a terrestrial access node, such as an eNB (or more generally a terrestrial base station). In another example, network 310 can be at least partially a non-terrestrial network, where the network node 320 can be implemented on a communication satellite. In this case, the network node 320 can be referred to as a non-terrestrial base station and can be coupled to the terrestrial network via a gateway 332.

[0064] Generally, the network node 320 can cover a large geographical area, where this area can be divided into a large number of cells (possibly hundreds if not thousands). The UE 304 can be located in a cell (shown as Figure 3350 in the cell 350) and can be connected to the network node 320 via the feeder link 324. In this way, the UE 304 can access the network 310 via the network node 320.

[0065] NTN coverage 300 may vary geographically over time. For example, during certain time intervals, network coverage 300 is available to UE 304 located in cell 350. During other time intervals, network coverage 300 is unavailable to UE 304 at the same location, and thus NTN 320 may stop providing service to cell 350 at that location.

[0066] For the sake of clarity of explanation, various embodiments are described below in conjunction with a communication satellite as an example of network node 320. In addition, these various embodiments are described in conjunction with a device with a narrowband Internet of Things (NB-IoT) configuration. However, the embodiments are not limited thereto and are similarly applicable to any other base station belonging to a network providing discontinuous network coverage and / or any other device to which discontinuous network coverage can be provided. In addition, the cause of discontinuous network coverage can be attributed to several factors, such as the repositioning of the communication satellite (e.g., with respect to a mobile cell), a change in the beam direction and / or a change in the location of the device (e.g., with respect to a quasi-earth fixed cell, where the device may be relocated from the coverage area of ​​the cell to a geographic area where the network coverage is unavailable) or a combination thereof. These embodiments are applicable to any situation where such discontinuous network coverage has occurred.

[0067] For NTN networks, the quasi-terrestrial fixed cell scenario can be described in association with a reference location and a threshold distance. Generally speaking, the location information refers to the reference location (ReferenceLocation) of the serving cell. If the distance between the UE and the ReferenceLocation is greater than or equal to the threshold distance (distanceThresh), the UE shall perform intra-frequency measurement, inter-frequency measurement or inter-RAT measurement.

[0068] For NTN networks, the quasi-geo-fixed cell scenario may also be described in association with time-based cell selection / reselection measurements. The timing information (e.g., t-service) refers to the serving cell (e.g., NTN serving cell, such as Figure 3 The time when the serving cell 350 will stop serving a geographical area. If the t-service of the serving cell is present in the system information block (SIB) 19, the UE shall perform intra-frequency measurements, inter-frequency measurements or inter-RAT measurements before the t-service. The exact time to start the measurement before the t-service may depend on the UE specific implementation.

[0069] Efforts are ongoing to specify further enhancements for NTN based on Evolved Universal Terrestrial Access (E-UTRA) (LTE-RAN) based on the following assumptions: Geosynchronous Orbit (GSO) and Non-Geosynchronous Orbit (NGSO) (Low Earth Orbit (LEO) and Medium Earth Orbit (MEO)); Geofixed Tracking Areas (Geofixed cells and Geomobile cells for NGSO); Frequency Division Duplex (FDD) mode; and UEs with GNSS capabilities.

[0070] The objectives of these efforts include: IoT-NTN performance enhancements to address R17 related issues (disabling HARQ feedback to mitigate the impact of HARQ stalling on UE data rate; studying and specifying improved GNSS operations, if necessary, to achieve new position fixes for UE pre-compensation during long connection times and to achieve reduced power consumption). The R17 IoT-NTN work and the R17 New Radio (NR)-NTN results can be considered as baselines; mobility enhancements (supporting neighbor cell measurements and corresponding measurement triggering before RLF, using R17 TN NB-IoT, enhanced machine type communication (eMTC) as a baseline; and reusing the solutions introduced in R17 NR NTN for mobility enhancements for eMTC, where they are adapted to eMTC with only minimal necessary changes); and further enhancements to discontinuous coverage.

[0071] As part of or regardless of such efforts, there are different challenges. For example, the quasi-terrestrial fixed cell goes out of service after t-service, so the RLF may be caused by satellite movement. The NTN cell signal does not degrade drastically compared to the TN cell. Therefore, when the UE moves to the cell edge of the NTN cell, the RSRP is still good (see, for example, Figure 4 400). NTN cells may have more coverage holes, in which the UE should avoid fast RRC re-establishment. If no neighboring NTN / TN cells are available, long RRM only causes UE power consumption.

[0072] Various embodiments of the present disclosure address some or all of the above challenges and / or other challenges. Some factors considered with respect to the embodiments may include: UE movement speed is negligible compared to satellite movement speed, and when the UE moves to the cell edge, the serving cell channel quality may be very good.

[0073] Figure 4 illustrates coverage scenarios according to some embodiments. Figure 4The left hand side of FIG. 4 shows the coverage of a terrestrial network 400. Specifically, a TN node 410 (eg, a TN eNB) provides a cell. The coverage of the cell is shown as having an elliptical boundary, where services are available to UEs located within the elliptical boundary. Figure 4 In the example of , when the UE is located at the cell center 420, the UE may have the highest RRM measurement result (eg, such as a peak of the RSRP measurement result 440). When the UE is located at the cell edge 430, the RRM measurement result is relatively much smaller.

[0074] exist Figure 4 The right hand side of FIG. 4 shows the coverage of the non-terrestrial network 450. Specifically, the NTN node 460 (eg, NTNeNB) provides a cell. The coverage of the cell is also shown as having an elliptical boundary, where services are available to UEs located within the elliptical boundary. Figure 4 In the example of , when the UE is located at the cell center 470, the UE may have the highest RRM measurement result (eg, such as a peak value of the RSRP measurement result 490). When the UE is located at the cell edge 430, the RRM measurement result is relatively much smaller.

[0075] There may be variations in the RRM measurement behavior (e.g., its distribution depends on the location of the UE relative to the cell center), which depends essentially on whether TN coverage or NTN coverage is provided. For example, when comparing RSRP measurement result 440 with RSRP measurement result 490, it can be seen that the RSRP peak is relatively large in the TN coverage use case. In the TN coverage use case, the RSRP value also degrades at a relatively high rate as the UE approaches the cell edge. Due to these differences, the conditions defined for TN coverage (e.g., Figure 2 The conditions for TN NB-IoT UEs in ( ) may not be suitable for NTN coverage.

[0076] Figure 5 Timing-based RRM measurements 500 according to some embodiments are illustrated. As illustrated, a UE 520 is connected to an NTN service cell 510 of an NTN node (e.g., an NTN eNB implemented on a satellite) such that the UE 520 has NTN coverage. The NTN service cell 510 may move relative to the UE 520, and / or the UE 520 may move relative to the NTN 510. In both cases, the NTN coverage changes over time. After a certain point in time, as shown by t-service 530, the network NTN coverage may become unavailable to the UE 520 due to the end of the NTN (where "unavailable" may refer to the NTN coverage not existing or having a channel quality below a first predetermined threshold and a change greater than a second predetermined threshold). Figure 5In the example of , on t-service 530, UE 520 may be located at or near the edge of NTN serving cell 510 (although other relative locations on t-service 530 are possible). Prior to this point in time (e.g., t-service 530), the UE may begin performing RRM measurements. This RRM measurement may include intra-frequency measurements, inter-frequency measurements, and / or inter-RAT measurements for neighboring NTN cells (e.g., provided by the same or different NTN nodes) and / or neighboring TN cells.

[0077] In some embodiments, t-service 530 may be a satellite t-service. In this case, the network (e.g., Figure 3 The network 310 (such as a component thereof) may indicate the value of the t-service 530 to the UE 520. For example, a system information block (SIB) message such as a SIB3-NB message may be sent to the UE and may include information indicating this value. The UE 520 may start performing neighboring NTN / TN cell measurements before the t-service 530. There are different options for when the UE 520 may start performing such measurements.

[0078] In a first option, the network may configure the UE 520 to start RRM measurements at an exact point in time before t-service 530. For example, SIB3-NB indicates the value of the exact point in time (in Figure 5 Additionally or alternatively, the network may configure a time window 550 during which the UE may start or need to perform RRM measurements. This time window 550 may end on or before t-service 530. Figure 5 In the example of , the time difference between t-service 530 and the start time point 540 corresponds to a time window 550. Therefore, at the beginning of the time window 550 or at a certain time during the time window, the UE 520 may perform RRM measurement 560.

[0079] In a second option, the timing may not be configured by the network. Alternatively, the exact time point or time window may depend on the specific implementation of the UE 520.

[0080] The network may specify t-service 530 (eg, the point in time at which the current satellite stops serving UE 520) to UE 520 for NTN serving cell 510. This specification may involve sending one or more SIB messages (eg, SIB3-NB messages).

[0081] UE 502 may decide which satellite (or which cell) to measure based on other information configured by the network. For example, for NB-IOT, one or more SIB 32 messages may be used to indicate ephemerisOrbitalParameters (e.g., information related to the location of the satellite) and the t-service of the neighboring NTN cell. If the neighboring NTN cell is not available (e.g., during the time window 550), UE 502 may skip RRM measurement 560.

[0082] The UE 520 may also decide which TN cell and / or frequency to measure based on the configured frequency and / or cell. Such configuration information may also be obtained from SIB messages, which include, for example, one or more SIB4-NB messages that may be used to indicate intra-frequency neighbor cell measurements and / or one or more SIB5-NB messages that may be used to indicate inter-frequency neighbor cell measurements.

[0083] In some embodiments, when conditions other than the timing-based conditions described above are met, UE 502 may begin performing neighboring NTN / TN cell measurements. These conditions may include: in addition to determining that t-service 530 is approaching (as described above in Figure 5 ), the channel quality of the NTN serving cell 510 is below a predetermined threshold (e.g., as in Figure 2 ) and the channel quality changes rapidly (e.g., as in Figure 2 as in the first condition discussed in ).

[0084] Some embodiments may include enhancements to the priority order of frequencies during RRM for NB-IoT. For example, when UE 520 performs RRM measurements on neighboring cells, the network may indicate which frequency and / or cell (NTN or TN) is prioritized. When performing RRM measurements, UE 520 may follow the prioritization configuration of neighboring frequencies in the SIB. For example, the network may configure the priority of each frequency and / or cell (e.g., by using a priority index). Based on this configuration, UE 520 may determine a set of frequencies and / or cells with a higher priority relative to the priority associated with the NTB serving cell 510, and perform RRM measurements continuously. In contrast, UE 520 may determine a set of frequencies and / or cells with a lower priority relative to the priority associated with the NTB serving cell 510, and perform RRM measurements when it is determined that the above conditions are met.

[0085] Figure 6Location-based RRM measurements 600 according to some embodiments are illustrated. As illustrated, a UE 620 is connected to an NTN serving cell 610 of an NTN node (e.g., an NTN eNB implemented on a satellite) such that the UE 620 has NTN coverage. The NTN serving cell 610 may move relative to the UE 620, and / or the UE 620 may move relative to the NTN 610. In both cases, the NTN coverage varies over time. The NTN serving cell 610 may be associated with a reference location 612. When the relative distance between the UE 620 and the reference location 612 becomes large (e.g., exceeds a predetermined threshold), the UE 620 may start performing RRM measurements. In general, the relative distance at which the UE 620 may start performing RRM measurements corresponds to a clearance distance to the edge of the NTN serving cell 610, wherein this clearance distance may correspond to a predetermined threshold. In other words, when the UE 620 is far enough from the reference location 612 and close enough to the edge of the NTN serving cell 610 (still within the boundary of the NTN serving cell), the UE 620 may perform RRM measurements.

[0086] In some cases, there may be neighboring cells (such as Figure 3 Here, the neighboring cell may also move relative to the UE 620 (in terms of the NTN neighboring cell 630) and / or the UE 620 may also move relative to the neighboring cell. The neighboring cell may also be associated with a reference location (shown as a reference location 632 for the NTN neighboring cell 630). The relative distance between the UE 620 and this reference location may indicate whether network coverage of the neighboring cell to the UE 620 is possible. Where possible, at least RRM measurements for the neighboring cell may be performed. Otherwise, this RRM measurement may be skipped. In other words, instead of performing RRM measurements solely based on the relative distance between the UE 620 and the reference location 612 of the NTN serving cell 610, RRM measurements may also be performed based on the relative distance between the UE 620 and the reference location of the neighboring cell, so that RRM measurements may be skipped when not necessary (e.g., when no coverage of the neighboring cell is available to the UE 620).

[0087] In some embodiments, for quasi-earth fixed satellites, when the relative distance between the UE and the referenceLocation of the serving satellite is greater than (or less than, depending on the physical meaning of referenceLocation) a threshold, the UE 620 starts performing neighboring NTN / TN cell RRM measurements.

[0088] In some embodiments, the network may specify reference locations of the serving cell and / or neighboring cells in quasi-Earth fixed satellites. For example, one or more SIB messages may be used to configure the values ​​of these reference locations for the UE 620.

[0089] When the UE 620 moves to a place where the relative distance between its position and the reference position is greater than a first threshold, the UE 620 may start neighbor cell measurement. Figure 6 In the example of , at a first time, UE 620 is located at a first location within NTN serving cell 610. UE 620 determines a first relative distance 640 between UE 620 and a reference location 612 referred to as "referenceLocation1", (e.g., a distance difference between the first distance and referenceLocation1 which may be set in a SIB message). UE 620 may compare the first relative distance 640 to a first threshold referred to as "distanceThreshFromReference1" which may also be set in the SIB message. Figure 6 In the example of , the comparison indicates that the first relative distance 640 is less than the first threshold. Therefore, the UE 620 does not start performing RRM measurements.

[0090] At a second time, UE 620 is located at a second position within NTN serving cell 610. UE 620 determines a second relative distance 650 between UE 620 and reference position 612. UE 620 may compare second relative distance 650 to the first threshold. Figure 6 In the example of , the comparison indicates that the second relative distance 650 is greater than the first threshold. Therefore, the UE 620 may start performing RRM measurements 660.

[0091] Still in Figure 6 In the example of , UE 620 can decide which neighboring NTN cell to measure based on the reference position configuration of the neighboring satellite in the SIB message (e.g., one or more SIB3-NB messages). Here, UE 620 can determine the reference location 632 of the NTN serving cell 630, which is referred to as "referenceLocation2". UE 620 determines a third relative distance 670 between UE 620 and referenceLocation2. UE 620 can compare the third relative distance 670 with a second threshold called "distanceThreshFromReference2" which can also be set in the SIB message. Figure 6In the example of , the comparison indicates that the third relative distance 670 is less than the second threshold. Therefore, the UE 620 may start performing RRM measurements 660. Otherwise, the UE 620 may determine that no NTN neighboring cells are available and may therefore skip the RRM measurements 660.

[0092] The UE 620 may also decide which TN cell and / or frequency to measure based on the configured frequency and / or cell. Such configuration information may also be obtained from SIB messages, including, for example, one or more SIB4-NB messages that may be used to indicate intra-frequency neighbor cell measurements and / or one or more SIB5-NB messages that may be used to indicate inter-frequency neighbor cell measurements.

[0093] In some embodiments, when conditions other than the location-based conditions described above are met, UE 502 may begin to perform neighboring NTN / TN cell measurements. These conditions may include: in addition to determining based on the reference location information that UE 620 is moving toward the edge of NTN serving cell 610 (as described above in Figure 6 ), the channel quality of the NTN serving cell 610 is below a predetermined threshold (e.g., as in Figure 2 ) and the channel quality changes rapidly (e.g., as in Figure 2 as in the first condition discussed in ).

[0094] Some embodiments may include enhancements for earth mobile cells where the reference location is constantly changing.For example, UE 620 may calculate the relative distance between its location and the reference location by tracking both locations in the same coordinate system.

[0095] Figure 5 and Figure 6 The timing-based RRM measurements and location-based RRM measurements are illustrated as two possible separate and independent schemes. However, it is possible to use these schemes in combination. Specifically, when Figure 5 (e.g., t-service is approaching) and Figure 6 When the two conditions (the distance to the reference position is large) are met, RRM measurements can be performed.

[0096] Figure 7An RRM measurement 700 based on network coverage holes according to some embodiments is illustrated. As illustrated, a UE 720 is connected to an NTN serving cell 710 of an NTN node (e.g., an NTN eNB implemented on a satellite) such that the UE 720 has NTN coverage. The NTN serving cell 710 may move relative to the UE 720, and / or the UE 720 may move relative to the NTN 710. In both cases, the NTN coverage varies over time. In some cases, coverage holes may occur. For example, UE 720 may still be within NTN serving cell 710, but the channel quality of NTN serving cell 710 is low (e.g., NRSRP measurement result of UE 720 and / or a certain measurement result of NTN serving cell 710 is less than a threshold, such as less than s-MeasureIntra or s-MeasureInter), even when UE 720 is not close to the edge of NTN serving cell 710 (e.g., the relative distance between UE 720 and the reference location 712 of NTN serving cell is less than a threshold, such as referenceLocation is less than distanceThreshFromReference). In this case, it can be expected that the channel quality can improve over time, and there may be no other neighboring cells available. Therefore, it may be wasteful to perform RRM measurements when UE 720 is located in a coverage hole. Instead, UE 720 may skip the performance of RRM measurements unless a set of conditions are met.

[0097] In one example, the set of conditions involves channel quality and relative distance. Figure 7 This set of conditions is illustrated as condition 730 in . Specifically, UE 720 can determine the relative distance between UE 720 and reference location 712, and can determine the channel quality (e.g., based on NRSRP measurement and / or a measurement of NTN serving cell 710). If the relative distance is greater than a first predetermined threshold (e.g., distanceThreshFromReference) and if the channel quality is lower than a second predetermined threshold (e.g., s-MeasureIntra or s-MeasureInter), UE 720 performs RRM measurement 740 (e.g., intra-frequency measurement or inter-frequency measurement, as appropriate). Otherwise, RRM measurement 740 is not performed. Here, the network can configure these thresholds. For example, one or more SIB messages can be used to indicate the values ​​of these thresholds.

[0098] In another example, the timer relaxation may be configured by the network (e.g., via a SIB message) or predefined in a technical specification. When the channel quality is low (e.g., below a second predetermined threshold), the change in channel quality is fast, and / or the relative distance is small (e.g., less than a first predetermined threshold), the timer relaxation may relax (e.g., increase) the duration for which the UE 720 is allowed to not perform RRM measurements. Figure 2 , timer T310 may be configured to be relatively long for UE 720 (e.g., relative to Figure 2 ), thereby allowing UE 720 to recover from a coverage hole (eg, without declaring RLF).

[0099] Thus, in some instances, there may be a coverage hole where the channel quality of the serving cell is low, but the UE 720 is not located at the NTN cell edge. If the UE 720 is located in a coverage hole, it may be desirable to avoid fast RRC re-establishment because there may be no other available satellites nearby for the UE 720 to access.

[0100] In some embodiments, the serving cell channel quality threshold may be used in conjunction with referenceLocation as discussed elsewhere herein. The network may configure the UE 720 with both the serving cell channel quality threshold and referenceLocation. When both conditions are met (e.g., the serving cell channel quality is below the serving cell channel quality threshold and the reference location is greater than distanceThreshFromReference), the UE 720 may start RRM measurements on neighboring NTN / TN cells.

[0101] In some embodiments, a relatively longer T310 may be configured for the UE 720 to enable the UE 720 to recover from a coverage hole (eg, without declaring RLF).

[0102] Figure 8 810. Timer-based RRM measurements according to some embodiments are illustrated. As illustrated, UE 820 is connected to NTN serving cell 710 of an NTN node (e.g., an NTN eNB implemented on a satellite) such that UE 820 has NTN coverage. NTN serving cell 810 may move relative to UE 820 and / or UE 820 may move relative to NTN 810. In both cases, NTN coverage varies over time. In some cases, neighboring cell 820 (e.g., NTN neighboring cell or TN neighboring cell) may be unavailable to UE 820 (e.g., NTN neighboring cell or TN neighboring cell). Figure 8810 and the neighborCellMeasCriteria parameter are not configured, and the length of time for which the UE should perform RRM measurements is undefined.

[0103] The implementation scheme can resolve this timer uncertainty. Specifically, the implementation scheme provides that when the neighborCellMeasCriteria parameter is not configured, the UE 820 performs the connected RRM measurement for a limited duration. The network can configure the duration (which can be different from T3XX or T326) to the UE 820. In this case, one or more SIB messages can be used for the configuration. Alternatively or additionally, the UE 820 can determine the duration by itself. Alternatively or additionally, the duration can be defined in a technical specification that the UE 820 is compatible with.

[0104] If UE 820 cannot find a neighboring cell when the timer (as described above) expires, UE 840 can stop RRM measurements. When UE 840 restarts RRM measurements (e.g., the next RRM measurement), a specific implementation can be specific to UE 820. For example, this specific implementation can be based on the ephemeris data of the satellite. Specifically, the ephemeris data can be received in one or more SIB data and can indicate the position, movement and / or orbit of the serving satellite. Therefore, UE 820 can estimate the time when the next NTN coverage can start. The restart time can be set based on this estimated time (e.g., so as to coincide with the estimated time, shortly before the estimated time (such as one hundred milliseconds before the estimated time), or shortly after the estimated time (such as one hundred milliseconds after the estimated time)).

[0105] exist Figure 8 In the example of FIG. 8 , UE 820 is located at the edge of NTN serving cell 810 (although when the relative distance between UE 820 and the reference position of NTN serving cell 810 is like Figure 6 or Figure 7820 is greater than a threshold as in , the embodiments may be similarly and equivalently applicable). The UE 820 may start performing RRM measurements 850, where this execution lasts for a duration 840 configured by the network (as a timer different from T3XX or T326), implemented by the UE 820, or specified in the technical specification. After the time window 840 ends, the UE 820 stops the execution. The UE 820 may then determine a restart time point for the next RRM measurement 870 (e.g., based on ephemeris data). At the restart time point, the UE performs the next RRM measurement 870 during the next time window 860, which may have the same length as the time window 840 by having the same configuration.

[0106] Fig. 9 An example of an operational flow / algorithm structure implemented for managing the execution of RRM measurements according to some embodiments is illustrated. The operational flow / algorithm structure 900 may be performed or implemented by a UE (such as any of the UEs described herein above) or a component thereof (e.g., processor 1004).

[0107] The operational flow / algorithm structure 900 may include detecting a condition at 910 before a point in time when a non-terrestrial network (NTN) node will stop providing service to a UE. The condition may be, for example, Figure 5 The timing-based conditions related to, for example, t-service described in Figure 6 The location-based conditions described in Figure 7 Covering holes as described in and / or Figure 8 Additional conditions can also be monitored. Fig. 9 As illustrated in , operation 902 may include multiple sub-operations 912-916. For example, the operation flow / algorithm structure 900 may include determining at 912 that the channel quality of the serving cell is lower than a first predetermined threshold. The channel quality of the serving cell may be an NRSRP measurement result. The first predetermined threshold may be s-MeasureIntra or s-MeasureInter. The operation flow / algorithm structure 900 may also include determining at 914 that the time point is within a predetermined threshold time period and / or the distance to the reference location is greater than a predetermined threshold distance. The time point may be such as Figure 5 The distance can be defined relative to t-service. Figure 6 The operation flow / algorithm structure 900 may also include determining, at 916, that a change in channel quality is above a second predetermined threshold. The second predetermined threshold may be s-MeasureDeltaP.

[0108] The operation flow / algorithm structure 900 may include performing RRM measurements before the time point based on the condition at 910 to attempt to measure neighboring cells. The neighboring cells may be NTN neighboring cells or TN neighboring cells. The RRM measurements may include inter-frequency measurements and / or intra-frequency measurements.

[0109] Fig.10 An example of an example UE 1000 according to some embodiments is illustrated. UE 1000 may correspond to any of the UEs described herein above, and may be any mobile or non-mobile computing device, such as, for example, a mobile phone, a computer, a tablet, an industrial wireless sensor (e.g., a microphone, a carbon dioxide sensor, a pressure sensor, a humidity sensor, a thermometer, a motion sensor, an accelerometer, a laser scanner, a fluid level sensor, an inventory sensor, a voltage / current meter, or an actuator), a video surveillance / monitoring device (e.g., a camera), a wearable device (e.g., a smart watch), or an Internet of Things (IoT) device.

[0110] UE 1000 may include a processor 1004, an RF interface circuit 1008, a memory / storage device 1012, a user interface 1016, a sensor 1020, a driving circuit 1022, a power management integrated circuit (PMIC) 1024, an antenna structure 1026, and a battery 1028. The components of UE 1000 may be implemented as an integrated circuit (IC), a portion of an integrated circuit, a discrete electronic device or other module, logic component, hardware, software, firmware, or a combination thereof. Fig.10 The block diagram of UE 1000 is intended to show a high-level view of certain of the components of UE 1000. However, some of the components shown may be omitted, additional components may be present, and different arrangements of the components shown may occur in other implementations.

[0111] Components of UE 1000 may be coupled to various other components via one or more interconnects 1032, which may represent any type of interface, input / output, bus (local, system, or extension), transmission line, trace, optical connection, etc., which allows various circuit components (on a common or different chip or chipset) to interact with each other.

[0112] The processor 1004 may include processor circuits, such as, for example, a baseband processor circuit (BB) 1004A, a central processor unit circuit (CPU) 1004B, and a graphics processor unit circuit (GPU) 1004C. The processor 1004 may include any type of circuit or processor circuit that executes or otherwise operates computer-executable instructions (such as program codes, software modules, or functional processes from the memory / storage device 1012) to cause the UE 1000 to perform operations as described herein.

[0113] In some embodiments, the baseband processor circuit 1004A can access the communication protocol stack 1036 in the memory / storage device 1012 to communicate through a 3GPP compatible network. Generally speaking, the baseband processor circuit 1004A can access the communication protocol stack to: perform user plane functions at the PHY layer, MAC layer, RLC layer, PDCP layer, SDAP layer, and PDU layer; and perform control plane functions at the PHY layer, MAC layer, RLC layer, PDCP layer, RRC layer, and non-access layer. In some embodiments, the PHY layer operations can be additionally / alternatively performed by components of the RF interface circuit 1008.

[0114] The baseband processor circuit 1004A may generate or process baseband signals or waveforms that carry information in a 3GPP-compatible network. In some embodiments, the waveforms used for NR may be based on cyclic prefix OFDM (CP-OFDM) in the uplink or downlink, and discrete Fourier transform spread OFDM (DFT-S-OFDM) in the uplink.

[0115] The memory / storage 1012 may include one or more non-transitory computer-readable media including instructions (e.g., the communication protocol stack 1036) that may be executed by one or more processors in the processor 1004 to cause the UE 1000 to perform various operations described herein. The memory / storage 1012 includes any type of volatile or non-volatile memory that may be distributed throughout the UE 1000. In some embodiments, some of the memory / storage 1012 may be located on the processor 1004 itself (e.g., L1 cache and L2 cache), while other memory / storage 1012 is located external to the processor 1004 but accessible via a memory interface. The memory / storage 1012 may include any suitable volatile or non-volatile memory, such as, but not limited to, dynamic random access memory (DRAM), static random access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid-state memory, or any other type of memory device technology.

[0116] The RF interface circuit 1008 may include a transceiver circuit and a radio frequency front end module (RFEM), which allows the UE 1000 to communicate with other devices through a radio access network. The RF interface circuit 1008 may include various elements arranged in a transmit path or a receive path. These elements may include, for example, switches, mixers, amplifiers, filters, synthesizer circuits, control circuits, etc.

[0117] In the receive path, the RFEM may receive the radiated signal from the air interface via the antenna structure 1026 and continue to filter and amplify the signal (using a low noise amplifier). The signal may be provided to the transceiver's receiver, which down-converts the RF signal to a baseband signal that is provided to the baseband processor of the processor 1004.

[0118] In the transmit path, the transmitter of the transceiver up-converts the baseband signal received from the baseband processor and provides the RF signal to the RFEM. The RFEM may amplify the RF signal through a power amplifier before the signal is radiated across the air interface via the antenna 1026.

[0119] In various embodiments, the RF interface circuit 1008 may be configured to send / receive signals in a manner compatible with NR access technology.

[0120] Antenna 1026 may include antenna elements to convert electrical signals into radio waves to travel through the air and convert received radio waves into electrical signals. These antenna elements may be arranged into one or more antenna panels. Antenna 1026 may have an antenna panel that is omnidirectional, directional, or a combination thereof to achieve beamforming and multi-input, multi-output communications. Antenna 1026 may include a microstrip antenna, a printed antenna manufactured on the surface of one or more printed circuit boards, a patch antenna, a phased array antenna, etc. Antenna 1026 may have one or more panels that are designed for a specific frequency band including a band in FR1 or FR2.

[0121] The user interface circuit 1016 includes various input / output (I / O) devices designed to enable a user to interact with the UE 1000. The user interface 1016 includes input device circuits and output device circuits. The input device circuit includes any physical or virtual components for accepting input, including in particular one or more physical or virtual buttons (e.g., a reset button), a physical keyboard, a keypad, a mouse, a touchpad, a touch screen, a microphone, a scanner, a headset, etc. The output device circuit includes any physical or virtual components for displaying information or otherwise conveying information (such as sensor readings, actuator positions, or other similar information). The output device circuit may include any number or combination of audio or visual displays, including in particular one or more simple visual outputs / indicators (e.g., binary state indicators (such as light emitting diodes "LEDs") and multi-character visual outputs), or more complex outputs, such as display devices or touch screens (e.g., liquid crystal displays (LCDs), LED displays, quantum dot displays, projectors, etc.), where the output of characters, graphics, multimedia objects, etc. is generated or produced by the operation of the UE 1000.

[0122] Sensors 1020 may include devices, modules, or subsystems that are designed to detect events or changes in their environment and communicate information about the detected events (sensor data) to some other device, module, subsystem, etc. Examples of such sensors include, among others: an inertial measurement unit including an accelerometer, gyroscope, or magnetometer; a microelectromechanical system or nanoelectromechanical system including a three-axis accelerometer, a three-axis gyroscope, or a magnetometer; a level sensor; a flow sensor; a temperature sensor (e.g., a thermistor); a pressure sensor; a barometric pressure sensor; a gravity meter; an altimeter; an image capture device (e.g., a camera or a lensless aperture); a light detection and ranging sensor; a proximity sensor (e.g., an infrared radiation detector, etc.); a depth sensor; an ambient light sensor; an ultrasonic transceiver; a microphone or other similar audio capture device; and the like.

[0123] The driver circuit 1022 may include software and hardware elements for controlling specific devices embedded in, attached to, or otherwise communicatively coupled to the UE 1000. The driver circuit 1022 may include various drivers to allow other components to interact with or control various input / output (I / O) devices that may be present in or connected to the UE 1000. For example, the driver circuit 1022 may include: a display driver for controlling and allowing access to a display device, a touch screen driver for controlling and allowing access to a touch screen interface, a sensor driver for obtaining sensor readings of the sensor circuit 1020 and controlling and allowing access to the sensor circuit 1020, a driver for obtaining an actuator position of an electromechanical component or controlling and allowing access to an electromechanical component, a camera driver for controlling and allowing access to an embedded image capture device, and an audio driver for controlling and allowing access to one or more audio devices.

[0124] The PMIC 1024 may manage power provided to various components of the UE 1000. Specifically, with respect to the processor 1004, the PMIC 1024 may control power source selection, voltage scaling, battery charging, or DC-DC conversion.

[0125] In some embodiments, the PMIC 1024 may control or otherwise be part of various power saving mechanisms of the UE 1000. For example, if the platform UE is in the RRC_Connected state, in which the platform is still connected to the RAN node because it expects to receive traffic soon, then after a period of inactivity, the platform may enter a state known as discontinuous reception mode (DRX). During this state, the UE 1000 may be powered off for short time intervals, thereby saving power. If there is no data traffic activity for an extended period of time, the UE 1000 may transition to the RRC_Idle state, in which it is disconnected from the network and does not perform operations such as channel quality feedback, handover, etc. The UE 1000 enters a very low power state and performs paging, at which time it wakes up again periodically to listen to the network and then powers off again. The UE 1000 may not receive data in this state; in order to receive data, the platform must transition back to the RRC_Connected state. Additional power saving modes may prevent the device from using the network for a time exceeding the paging interval (from a few seconds to a few hours). During this time, the device is completely unable to connect to the network and can be completely powered off. Any data transmitted during this time will be significantly delayed, and it is assumed that the delay is acceptable.

[0126] The battery 1028 can power the UE 1000, but in some examples, the UE 1000 can be installed and deployed in a fixed location and can have a power source coupled to the power grid. The battery 1028 can be a lithium-ion battery, a metal-air battery such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, etc. In some specific implementations, such as in vehicle-based applications, the battery 1028 can be a typical lead-acid car battery.

[0127] Fig.11 An example base station 1100 according to some embodiments is illustrated. The base station 1100 may be a base station as described elsewhere herein. The base station 1100 may include a processor 1104, an RF interface circuit 1108, a core network (CN) interface circuit 1112, a memory / storage circuit 1116, and an antenna structure 1126. When the base station 1100 is an AMF, the RF interface circuit 1108 and the antenna structure 1126 may not be included.

[0128] The components of base station 1100 may be coupled to various other components via one or more interconnects 1128 .

[0129] The processor 1104, RF interface circuit 1108, memory / storage circuit 1116 (including communication protocol stack 1110), antenna structure 1126 and interconnect 1128 may be similar to those with respect to Fig.10 Like-named elements are shown and described.

[0130] The CN interface circuit 1112 may provide connectivity for a core network (e.g., a 4th or 5th generation core network (4 / 5GC) using a 4 / 5GC compatible network interface protocol such as a carrier Ethernet protocol or some other suitable protocol). The network connectivity may be provided to / from the base station 1100 via optical fiber or wireless backhaul. The CN interface circuit 1112 may include one or more dedicated processors or FPGAs for communicating using one or more of the aforementioned protocols. In some implementations, the CN interface circuit 1112 may include multiple controllers for providing connectivity to other networks using the same or different protocols.

[0131] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of the authorized use should be clearly stated to users.

[0132] For one or more embodiments, at least one of the components shown in one or more of the foregoing figures may be configured to perform one or more operations, techniques, processes, or methods described in the following example section. For example, the baseband circuit described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples described below. For another example, the circuit associated with the UE, base station, or network element described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the embodiments described below in the example section.

[0133] Example

[0134] In the following sections, additional exemplary embodiments are provided.

[0135] Embodiment 1 includes a method of operating a user equipment (UE), the method comprising: detecting a condition before a point in time when a non-terrestrial network (NTN) node will stop providing service to the UE; and performing radio resource management (RRM) measurements before the point in time based on the condition to attempt to measure neighboring cells.

[0136] Embodiment 2 includes the method according to embodiment 1 or any other embodiment herein, the method further comprising: receiving an indication of the time point or a time window including the time point from a network.

[0137] Embodiment 3 includes a method according to embodiment 1 or some other embodiment according to claim 1 herein, wherein the neighboring cell is an NTN neighboring cell, and the method further comprises: receiving a system information block (SIB) 32 message; and selecting a neighboring cell based on the SIB 32 message.

[0138] Embodiment 4 includes the method according to embodiment 3 or any other embodiment herein, the method further comprising: selecting a neighboring cell based on the ephemeris orbit parameter or t-service indication in the SIB 32 message.

[0139] Embodiment 5 includes a method according to embodiment 1 or some other embodiment herein, wherein the neighboring cell is a terrestrial network (TN) neighboring cell, and the method further includes: receiving a system information block (SIB) 4 message or a SIB 5 message; and selecting a neighboring cell based on the SIB 4 message or the SIB 5 message.

[0140] Embodiment 6 includes the method according to embodiment 5 or any other embodiment herein, the method further comprising: selecting a neighboring cell based on the configured frequency in the SIB 4 message or the SIB 5 message.

[0141] Embodiment 7 includes a method according to embodiment 1 or some other embodiment herein, wherein detecting the condition includes: determining that the channel quality of the serving cell is lower than a first predetermined threshold; determining that the time point is within a predetermined threshold time period; and determining that the change in channel quality is higher than a second predetermined threshold.

[0142] Embodiment 8 includes the method according to embodiment 1 or any other embodiment herein, the method further comprising: selecting a neighboring cell based on priority information provided by a network.

[0143] Embodiment 9 includes the method according to embodiment 1 or any other embodiment herein, wherein the UE is a narrowband Internet of Things UE.

[0144] Embodiment 10 includes a method according to embodiment 1 or any other embodiment herein, wherein detecting the condition comprises: determining a reference position of a serving satellite; and comparing a relative distance between the UE and the reference position.

[0145] Embodiment 11 includes the method according to embodiment 10 or any other embodiment herein, the method further comprising: receiving an indication of the reference location from a network.

[0146] Embodiment 12 includes a method according to embodiment 10 or 11 or any other embodiment herein, wherein detecting the condition further comprises: determining that the first distance is greater than the first predetermined threshold; and determining that the second distance between the UE and the second reference position of the neighboring cell of the NTN is less than a second predetermined threshold.

[0147] Embodiment 13 includes a method according to embodiment 10, 11 or 12 or any other embodiment herein, wherein detecting the condition further comprises: determining that the channel quality of the serving cell is lower than a third predetermined threshold; and determining that a change in the channel quality is higher than a predetermined threshold.

[0148] Embodiment 14 includes a method according to embodiment 10 or any other embodiment herein, wherein detecting the condition further comprises: determining that the first distance is greater than the first predetermined threshold; and determining that the service cell channel quality is lower than a second predetermined threshold.

[0149] Embodiment 15 includes the method according to embodiment 1 or any other embodiment herein, the method further comprising: selecting a neighboring cell based on a reference location configuration in a SIB-3 message.

[0150] Embodiment 16 includes a method according to embodiment 1 or any other embodiment herein, the method further comprising: determining that a neighbor cell measurement standard parameter is not configured; detecting a duration based on the determination that the neighbor cell measurement standard is not configured; and limiting the execution of RRM measurements to the duration.

[0151] Embodiment 17 includes the method according to embodiment 16 or any other embodiment herein, the method further comprising: determining the duration based on a network configuration or a predefined UE configuration.

[0152] Embodiment 18 may include an apparatus comprising means for performing one or more elements of a method described in or related to any of Embodiments 1 to 17, or any other method or process described herein.

[0153] Embodiment 19 may include one or more non-transitory computer-readable media, which include instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of a method described in or related to any of Embodiments 1 to 17 or any other method or process described herein.

[0154] Embodiment 20 may include an apparatus comprising logic components, modules, or circuits for performing one or more elements of the method described in or related to any of Embodiments 1 to 17, or any other method or process described herein.

[0155] Embodiment 21 may include methods, techniques or processes as described in or related to any one of Embodiments 1 to 17, or portions or parts thereof.

[0156] Embodiment 22 may include a device such as a UE, comprising: one or more processors and one or more memories (e.g., one or more computer-readable media), the one or more memories comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform a method, technique, process, or portion thereof as described in or related to any one of Embodiments 1 to 17.

[0157] Embodiment 23 may include a signal as described in or related to any one of Embodiments 1 to 17, or a portion or part thereof.

[0158] Embodiment 24 may include a datagram, information element, packet, frame, segment, PDU or message, or a portion or part thereof, as described in or related to any one of Embodiments 1 to 17 or otherwise described in the present disclosure.

[0159] Embodiment 25 may include a signal encoded with data, or a portion or part thereof, as described in or related to any one of Embodiments 1 to 17 or as otherwise described in this disclosure.

[0160] Embodiment 26 may include a signal encoded with a datagram, IE, packet, frame, segment, PDU or message, or a portion or part thereof as described in or related to any of Embodiments 1 to 17 or otherwise described in the present disclosure.

[0161] Embodiment 27 may include an electromagnetic signal carrying computer-readable instructions, wherein execution of these computer-readable instructions by one or more processors will cause the one or more processors to perform a method, technique, or process, or a portion thereof, as described in or related to any of Embodiments 1 to 17.

[0162] Embodiment 28 may include a computer program comprising instructions, wherein execution of the program by a processing element causes the processing element to perform a method, technique, or process, or a portion thereof, as described in or related to any one of Embodiments 1 to 17.

[0163] Embodiment 29 may include signals in a wireless network as shown and described herein.

[0164] Embodiment 30 may include a method of communicating in a wireless network as shown and described herein.

[0165] Embodiment 31 may include a system for providing wireless communications as shown and described herein.

[0166] Embodiment 32 may include an apparatus for providing wireless communications as shown and described herein.

[0167] Unless explicitly stated otherwise, any of the above embodiments may be combined with any other embodiment (or combination of embodiments). The foregoing description of one or more specific implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise form disclosed. Modifications and variations are possible in view of the above teachings or may be obtained from the practice of various embodiments.

[0168] Although the above embodiments have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to include all such variations and modifications.

Claims

1. A method of operating a user equipment (UE), the method comprising: detecting a condition prior to a point in time at which a non-terrestrial network (NTN) node will stop providing service to the UE; as well as Radio resource management (RRM) measurements are performed before the time point based on the conditions to attempt to measure neighboring cells.

2. The method according to claim 1, further comprising: An indication of the time point or a time window including the time point is received from a network.

3. The method according to claim 1, wherein the neighboring cell is an NTN neighboring cell and the method further comprises: receiving a system information block (SIB) 32 message; as well as The neighboring cell is selected based on the SIB 32 message.

4. The method according to claim 3, further comprising: The neighboring cell is selected based on the ephemeris orbit parameter or the t-service indication in the SIB 32 message.

5. The method of claim 1, wherein the neighboring cell is a terrestrial network (TN) neighboring cell and the method further comprises: Receiving a system information block (SIB) 4 message or a SIB 5 message; as well as The neighboring cell is selected based on the SIB 4 message or the SIB 5 message.

6. The method according to claim 5, further comprising: The neighboring cell is selected based on a configured frequency in the SIB 4 message or the SIB 5 message.

7. The method of claim 1, wherein detecting the condition comprises: Determining that the serving cell channel quality is lower than a first predetermined threshold; determining that the time point is within a predetermined threshold time period; as well as A change in channel quality is determined to be above a second predetermined threshold.

8. The method according to claim 1, further comprising: The neighboring cell is selected based on priority information provided by the network.

9. The method of claim 1, wherein the UE is a NB-IoT UE.

10. The method of claim 1, wherein detecting the condition comprises: Determining a first reference position of a serving cell of the NTN; as well as A first distance between the UE and the first reference location is compared with a first predetermined threshold.

11. The method according to claim 10, further comprising: An indication of the first reference location is received from a network.

12. The method according to claim 10 or 11, wherein detecting the condition further comprises: determining that the first distance is greater than the first predetermined threshold; as well as It is determined that a second distance between the UE and a second reference location of the neighboring cell of the NTN is less than a second predetermined threshold.

13. The method of claim 10, 11 or 12, wherein detecting the condition comprises: Determining that the serving cell channel quality is lower than a third predetermined threshold; as well as A change in channel quality is determined to be above a predetermined threshold.

14. The method of claim 10, wherein detecting the condition comprises: determining that the first distance is greater than the first predetermined threshold; as well as It is determined that the serving cell channel quality is lower than a second predetermined threshold.

15. The method according to claim 13, further comprising: The neighbor cell is selected based on a reference location configuration in a system information block (SIB) 3 message.

16. The method according to claim 1, further comprising: Determining that neighbor cell measurement standard parameters are not configured; detecting a duration based on the determining that the neighbor cell measurement criteria is not configured; as well as The performing of the RRM measurements is limited to the duration.

17. The method according to claim 13, further comprising: The duration is determined based on a network configuration or a predefined UE configuration.

18. The method according to claim 13 or 17, further comprising: stopping the RRM measurement at the end of the duration; determining a restart time based on ephemeris data associated with the NTN; as well as The RRM measurements are restated at the restart time.

19. A user equipment (UE), comprising one or more processors and one or more memories storing instructions, the instructions, when executed by the one or more processors, configuring the UE to perform the method according to any one of claims 1 to 18.

20. One or more computer-readable storage media storing instructions which, when executed on a user equipment (UE), cause the UE to perform the method according to any one of claims 1 to 18.

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