Satellite signal propagation delay variation compensation

Abstract

SOLUTION: A method for detecting satellite signal propagation delay variation includes: transmitting ephemeris data of a satellite and cell measurement window specifications to a terminal; receiving an indication from the terminal that a cell measurement signal will arrive at the terminal outside of a time frame defined by the cell measurement window specifications; modifying the cell measurement window specifications based on a difference in propagation delay between a serving cell, which defines the cell measurement window specifications, and a neighboring cell, which transmits the cell measurement signal, so that the cell measurement signal will arrive at the terminal within the time frame defined by the cell measurement window specifications, the satellite providing communication with the terminal for at least one of the serving cell and the neighboring cell; and transmitting modified cell measurement window specifications to the terminal.EFFECT: Satellite signal propagation delay variation can be compensated.SELECTED DRAWING: Figure 2A

Description

[Background technology]

[0001] While the terminal is connected to a serving cell of the network, a window of time is provided to the terminal during which the terminal can perform measurements on neighboring cell measurement signals, some of which may utilize satellites for communication.

[0002] Due to the movement of the satellites, the propagation delays of signals, including the measurement signals sent to the terminals, are constantly changing. For a given terminal, such delays may change over time as the satellites move. This movement also causes the measurement signal timing to drift.

[0003] If the terminal cannot perform measurements on neighboring cells, the terminal cannot report neighboring cell measurement results or cannot perform handover condition evaluation, which may affect handover performance. [Brief description of the drawings]

[0004] 1A and 1B are schematic diagrams of a system for compensating for satellite signal propagation delay variations in accordance with at least one embodiment of the present invention.

[0005] 2A and 2B are diagrams illustrating the relative timing between measurement windows and measurement signals in accordance with at least one embodiment of the present invention.

[0006] FIG. 3 is an operational flow for detecting satellite signal propagation delay variation in accordance with at least one embodiment of the present invention.

[0007] FIG. 4 is an operational flow for reporting satellite signal propagation delay variations in accordance with at least one embodiment of the present invention.

[0008] FIG. 5 is an operational flow for compensating for satellite signal propagation delay variations in accordance with at least one embodiment of the present invention.

[0009] FIG. 6 is a diagram illustrating the relative timing between measurement windows of varying duration and measurement signals in accordance with at least one embodiment of the present invention.

[0010] FIG. 7 is a diagram illustrating the relative timing between measurement windows and measurement signals with varying offsets in accordance with at least one embodiment of the present invention.

[0011] FIG. 8 is a diagram illustrating the relative timing between measurement windows and measurement signals with modified periodicity in accordance with at least one embodiment of the present invention.

[0012] FIG. 9 is a diagram illustrating the relative timing between an initially configured measurement window, an additional measurement window, and a measurement signal in accordance with at least one embodiment of the present invention.

[0013] FIG. 10 is an operational flow for further compensating for satellite signal propagation delay variations in accordance with at least one embodiment of the present invention.

[0014] FIG. 11 is a further operational flow for compensating for satellite signal propagation delay variations in accordance with at least one embodiment of the present invention.

[0015] FIG. 12 is a block diagram of an exemplary hardware configuration of a serving cell for satellite signal propagation delay variation compensation in accordance with at least one embodiment of the present invention.

[0016] FIG. 13 is a block diagram of an exemplary hardware configuration of a terminal for satellite signal propagation delay variation compensation in accordance with at least one embodiment of the present invention.

[0017] 14-30 are taken from US Provisional Patent Application No. 63 / 140,578, from which this application claims priority. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The following disclosure provides many different embodiments or examples for implementing different features of the provided subject matter. Specific examples of components, values, operations, materials, arrangements, etc. are described below to simplify the disclosure. These are, of course, merely examples and are not intended to be limiting. Other components, values, operations, materials, arrangements, etc. are also contemplated. In addition, the disclosure may repeat reference numerals and / or letters in the various examples. This repetition is for purposes of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and / or configurations discussed.

[0019] During handover of the terminal from the serving cell to the neighboring cell, the terminal may perform measurements to properly synchronize and connect to the neighboring cell. In some embodiments, such as when the serving cell and the neighboring cell operate on different carrier frequencies, the terminal cannot simultaneously communicate with the serving cell and synchronize and connect to the neighboring cell. Thus, in some wireless technologies, such as 5G NR, the network provides measurement gaps that enable the terminal to perform proper measurements with the neighboring cell to synchronize and connect to the neighboring cell. In some embodiments, such as 5G NR, the terminal performs measurements on the synchronization signal blocks (SSBs) of the neighboring cells during the measurement gaps. In some embodiments, the network provides the timing of the neighboring cell SSBs using the SSB-based Radio Resource Management (RRM) Measurement Time Configuration (SMTC) protocol.

[0020] The network provides the terminal with an SMTC specification that defines a window of time during which the terminal can perform measurements on neighbor cell SSBs while the terminal is connected to the serving cell. The SMTC specification includes the window periodicity, offset, and duration, and is based on the timing of the serving cell (also referred to as the Primary Cell (PCell)). The SMTC window periodicity (also referred to as the Measurement Gap Repetition Period (MGRP)) is, for example, 5, 10, 20, 40, 80, or 160 ms, and the SMTC window duration is, for example, 1, 2, 3, 4, or 5 ms. The serving cell does not schedule communication with the terminal during the measurement gap. The network ensures that SSBs from neighbor cells are sent during the measurement gap so that the terminal can measure the strength and quality of the neighbor cell SSBs. In some embodiments, the terminal generates neighbor cell measurements at standardized intervals.

[0021] In a Low Earth Orbit (LEO) Non-Terrestrial Network (NTN) scenario, the propagation delay for the nearby satellite cell SSB to reach the terminal changes constantly due to the movement of the satellite cells. The delay varies based on the relative position of the terminal on the ground. The nearby satellite cell delay also changes over time for the terminal as the satellite cells move. Due to this movement, the nearby satellite cell SSB timing measured by the terminal also drifts. The terminal also moves, but the effect of the terrestrial terminal movement is negligible compared to the speed of the satellite.

[0022] In the NTN scenario, the terminal is exposed to different propagation delays between the serving satellite cell and the neighboring satellite cells. In some situations, the SMTC window configuration and the SSB reception time are different for different satellite cells, such as between the cells of satellites at different positions. Reducing the size of the measurement gap allows more time to be spent on communication with the serving cell, rather than on measurements of neighboring cells. However, due to the small measurement gap size, there is a high risk that the terminal cannot acquire the SSB of the neighboring satellite cells for radio resource management (RRM) measurements, for neighboring cells of different frequencies or the same frequency. The SMTC window duration is at most 5 ms, and depending on the initial position of the SSB of the neighboring satellite cells in the SMTC window, the statically configured SMTC window cannot accommodate larger variations in the propagation delay. Measurement of neighboring satellite cells is challenging with the current SMTC configuration options, since the terminal is not required to monitor the SSB outside the configured SMTC window.

[0023] Variations in propagation delay exist for handovers between LEO satellites flying at the same altitude, are more pronounced for handovers between LEO satellites flying at different altitudes, and are even more pronounced for handovers between LEO satellites and Geostationary Earth Orbit (GEO) satellites. Furthermore, due to differences in location, over the same time period between the same satellites, each terminal experiences different variations in propagation delay. As described in R2-2010795 below, the SMTC window should be improved for NTN systems because it needs to keep up with the delay variations between serving and neighboring cells / satellites. "In the normal case of TN system, the SSB burst signal generated by the neighboring cell is always detectable within the corresponding SMTC window configured via the serving cell. Outside the corresponding SMTC window configured, there is no need for the UE to measure the SSB burst signal. However, for NTN system, the analysis shows that the SSB burst signal generated by the neighboring cell may be outside the corresponding SMTC window configured via the serving satellite. If the UE has the ability to acquire the propagation delay difference between the serving and neighboring satellites, the UE can still know when to detect the actual SSB burst signal generated by the neighboring cell even if the SSB burst signal is outside the corresponding SMTC window configured. If RAN2 does not want to refine the SMTC configuration for NTN, the UE should be allowed to search for the SSB burst signal generated by the neighboring cell even if it is outside the corresponding SMTC window configured." The SMTC window for SSB measurements established by the serving cell should attempt to take into account all possible SSB delays for all connected terminals.

[0024] 1A and 1B are schematic diagrams of a system for compensating for satellite signal propagation delay variations in accordance with at least one embodiment of the present invention, with Fig. 1A showing the system at an earlier time and Fig. 1B showing the system at a later time.

[0025] In Figures 1A and 1B, satellite 120A flying in LEO currently provides communications for NTN gateway 110A, which is the serving cell of terminal 100, and satellite 120B flying in LEO at a higher altitude than satellite 120A provides communications for NTN gateway 110B, which is a potential target neighbor cell. In this scenario, satellite 120A is moving away from terminal 100 along orbit 122A, and satellite 120B on a different orbit 122B is moving towards terminal 100. The propagation delay between satellite 120A and terminal 100 is represented as dSAT1-UE(t) (i.e., a function of time t), and the delay between satellite 120B and terminal 100 is represented as dSAT2-UE(t). In some embodiments, satellite 120A and satellite 120B do not support the NR protocol and instead simply relay signals from terrestrial gateways NTN gateway 110A and NTN gateway 110B, respectively. Such satellites are referred to as "transparent" in some examples. In some embodiments with transparent satellites, the propagation delay also depends on the relative positions of the gateway cells, which in some embodiments are NTN Gateway 110A and NTN Gateway 110B. In some embodiments, satellite 120A comprises a serving cell of the cellular network, and satellite 120B comprises a neighboring cell of the cellular network. They both fully support the NR protocol and function as satellite cells. Satellite 120A is moving toward its connected NTN Gateway 110A, and satellite 120B is moving toward its connected NTN Gateway 110B. FIG. 1A shows the relative positions of the satellites at a first time t1, and FIG. 1B shows the relative positions of the satellites at a second time t2. FIG. 1B shows that at time t2, satellite 120A has changed position by distance 124A, and satellite B has changed position by distance 124B. The respective propagation delays between the satellites and the gateway are dSAT1-GW1(t) and dSAT1-GW2(t).

[0026] Due to satellite movement, the propagation delay varies over time. Table 1 provides a numerical example based on estimated elevation angles between satellite cells and ground objects in one embodiment where satellite 120A is flying at an altitude of 600 km, satellite 120B is flying at an altitude of 1500 km, and both satellites 120A and 120B are transparent. [Table 1] Table 1: Propagation delay variation for terminal-gateway communication through transparent satellite

[0027] The timing of the terminal 100 is based on the serving cell (NTN gateway 110 communicating through satellite 120A in Figures 1A and 1B), so the terminal 100 experiences drift in the SSB from satellite 120B.

[0028] Based on the geometry shown in Figure 1 and Table 1, the total propagation delay between NTN gateway 110A and terminal 100 varies from about 5.1 ms to about 6.1 ms, and the total propagation delay between NTN gateway 110B and terminal 100 decreases from about 13.4 ms to about 10.6 ms. Thus, the difference in total propagation delay between the connection through satellite 120A and the connection through satellite 120B as observed by terminal 100 varies from 8.3 ms at t1 to 5.5 ms at t2. Thus, the SSB from NTN gateway 110B, which was adjusted to arrive within the SMTC window at t1 according to the configuration established by NTN gateway 110A, actually ends up outside the SMTC window at t2.

[0029] Figures 2A and 2B are diagrams illustrating the relative timing between measurement windows and measurement signals according to at least one embodiment of the present invention, where Figure 2A illustrates the relative timing at an earlier time, such as t1, in Figure 1A, and Figure 2B illustrates the relative timing at a later time, such as t2, in Figure 1B.

[0030] 2A shows an intended timeline 236 when the measurement windows and measurement signals are aligned. As a result of the alignment, measurement window 230A opens at time 232A, and measurement signal 237A sent at time 238A is received before measurement window 230A closes. Similarly, measurement window 230B opens at time 232B, and measurement signal 237B sent at time 238B is received before measurement window 230B closes.

[0031] FIG. 2B shows a resultant timeline 236 for the change in propagation delay caused by the satellite orbits shown in FIG. 1A and FIG. 1B. Because the total propagation delay between the NTN gateway 110A (serving cell) and the terminal 100 changes from about 5.1 ms to about 6.1 ms, the measurement window 230A starts at time 232A after a delay 233A of 1 ms. Because the total propagation delay between the NTN gateway 110B (neighboring cell) and the terminal 100 changes from about 13.4 ms to about 10.6 ms, the measurement signal 237A starts at time 238A with a 2.8 ms advance 239A. This results in the measurement signal 237A reaching the terminal 100 outside the measurement window 230A. Unless compensated, the terminal 100 will not receive the measurement signal 237A. A substantially similar effect is also exerted on the measurement window 230B and the measurement signal 237B.

[0032] 3 is an operational flow for detecting satellite signal propagation delay variation in accordance with at least one embodiment of the present invention. In some embodiments, the operational flow provides a method for detecting satellite signal propagation delay variation by a serving cell in communication with a terminal. In some embodiments, the operations are performed by a detection section or a subsection of the serving cell in communication with the terminal.

[0033] In S340, the detection section or a subsection thereof sends the satellite's orbit data and the cell measurement window specification to the terminal. If multiple terminals are connected to the serving cell, the detection section sends the orbit data and the cell measurement window specification to all connected terminals. In a situation like that of Figures 1A and 1B, where the serving cell and multiple of the neighboring cells use satellites to communicate with the terminal, the orbit data of each satellite is sent to the terminal.

[0034] In some embodiments, the cell measurement window specification includes a periodicity, duration, and offset. In some embodiments where cell measurements are performed according to the SMTC protocol, the serving cell defines the cell measurement window specification within which neighboring cells send cell measurement signals. In these embodiments, the cell measurement window specification includes a periodicity mgrp, a gap duration mgl, a gap timing advance mgta, and an offset gapOffset. In these embodiments, the gap duration mgl effectively sets the duration of the measurement window, since the measurement window is a time frame within a gap with non-transmission time on either side. Also, in SMTC protocol embodiments, the offset gapOffset is in the range of 0 to 1 times the periodicity mgrp. For example, if mgrp is 80, then the gapOffset ranges from 0 to 79. In SMTC protocol and other embodiments, the cell measurement window specification is sent through radio resource control (RRC) signaling as part of MeasConfig.

[0035] In some embodiments, the orbit data represents satellite position, satellite velocity, and reference position. In some embodiments where the satellites are transparent, the orbit data further represents the gateway position. In some embodiments, the orbit data is also sent through RRC signaling. In these and some other embodiments, the range and resolution of each value in the orbit data may affect the spectral efficiency and accuracy. In some embodiments, the satellite position is three coordinate values ​​using 84 bits with a range of ±50,000 km and a resolution of 0.4 m, the satellite velocity is three scalar values ​​using 60 bits with a range of ±8 km / s and a resolution of 0.015 km / s, and the reference position is three coordinate values ​​using 75 bits with a range of ±6500 km and a resolution of 0.4 m. In the SMTC protocol and other embodiments, the orbit data is sent through Radio Resource Control (RRC) signaling as part of MeasObjectNR.

[0036] In some embodiments, the detection section further sends one or more report conditions. In some embodiments, the report conditions include a delay report periodicity, a delay difference threshold, and a gap sequence value. In some embodiments, the delay report periodicity is significantly greater than the measurement window periodicity (e.g., greater than 1000 ms). In some embodiments, a delay difference threshold can be used to determine whether the terminal sends a report or includes a suggestion in the report. In some embodiments, two delay difference thresholds are used such that an alert is issued when the delay difference exceeds a higher threshold between 1 ms and 1000 ms, and the alert is active until the delay difference falls below a lower threshold between 1 ms and 1000 ms. Having a higher activation threshold and a lower deactivation threshold leads to reduced false positives and false negatives. In some embodiments, the gap sequence determines which neighboring cells send in which gaps within the same gap period or measurement window. In some embodiments where the terminal performs more analysis, a report condition is a determination by the terminal that a measurement signal arrives at the terminal outside of a time frame defined by the cell measurement window specification. In some embodiments, the detection section instructs the terminal to send a report in any case. In the SMTC protocol and other embodiments, the reporting conditions are sent through Radio Resource Control (RRC) signaling as part of the MeasObjectNR.

[0037] In S342, the detection section or a subsection thereof receives an indication from the terminal that a cell measurement signal will arrive at the terminal outside of a time frame defined by a cell measurement window specification. In some embodiments, the indication is received through RRC signaling. In some embodiments, the indication includes information representative of an offset between a measurement window and a measurement signal detected by the terminal that sent the indication, information that allows the serving cell to determine an offset between a measurement window and a measurement signal detected by the terminal that sent the indication, or any other information that may be used by the serving cell to determine an appropriate compensation. In some embodiments, the indication includes a confirmation that the cell measurement signal will arrive at the terminal within a time frame defined by a cell measurement window specification. In some embodiments, the indication includes a delay difference value that represents a difference in propagation delay between a serving cell and a neighboring cell of the cellular network. In a situation where more than one of the neighboring cells uses satellites to communicate with the terminal, multiple indications may be received from the terminal. In the case where multiple terminals are connected to the serving cell, the detection section may receive one or more indications from each connected terminal. In some embodiments, the indication includes a geographical location of the terminal, and in some of these embodiments, no other information.

[0038] In S344, the detection section or a subsection thereof determines whether all suggestions have been received, depending on the measurement window specification and the transmission of the orbit data. In some embodiments, the detection section refers to a time limit within which the terminal must send a suggestion or other criteria for determining that all suggestions considered have been received. In some embodiments, the terminal sends a suggestion regardless of whether the cell measurement signal reaches the terminal within the time frame defined by the cell measurement window specification, and the detection section waits until a suggestion is received from each connected terminal. If the detection section determines that all suggestions have been received according to the criteria, the operation flow proceeds to S346 to continue the detection process. If the detection section determines that the criteria have not been met, the operation flow returns to S342 to receive further suggestions.

[0039] In S346, the detection section or a subsection thereof determines the relative timing between the measurement window detected by the connected terminal and the measurement signals of any neighboring cells. In some embodiments, the connected terminal provides the relative timing directly in the indication received in S342. In some embodiments, the detection section determines whether there is an overlap based on other information provided by the terminal in the indication received in S342. In some embodiments, where the indication received in S342 includes the geographic location of the terminal, the detection section performs all the operations necessary to make the determination for each terminal for each neighboring cell. If the detection section determines that all measurement signals detected by the terminal of all received indications are received within the measurement window, the operation flow ends without further operations for compensation. If the detection section determines that the measurement signals are received outside the measurement window of the connected terminal, the operation flow proceeds to S360 to perform compensation. In some embodiments, the decision in S346 is not based on whether a single measurement signal arrives at a single terminal outside the measurement window, but instead is based on a threshold amount of the terminal, neighboring stations, some weighted factor criterion, etc.

[0040] In S360, the compensation section of the serving cell compensates for measurement signals that arrive at the terminal outside the measurement window defined by the measurement window specification sent in S340. In some embodiments, the compensation section or a subsection thereof modifies the cell measurement window specification such that the cell measurement signals sent from the satellite arrive at the terminal within the time frame defined by the cell measurement window specification. Some embodiments of the compensation operation in S360 are described in more detail with respect to FIG.

[0041] 4 is an operational flow for reporting satellite signal propagation delay variation in accordance with at least one embodiment of the present invention. In some embodiments, the operational flow provides a method for reporting satellite signal propagation delay variation by a terminal connected to a serving cell. In some embodiments, the operations are performed by a reporting section or a subsection of the terminal.

[0042] At S450, the reporting section or a subsection thereof receives satellite orbit data and cell measurement window specifications from a serving cell of the cellular network, the satellite orbit data and cell measurement window specifications being substantially similar to those described with respect to S340 of Figure 3. In some embodiments, the reporting section further receives reporting conditions, such as those described with respect to S340 of Figure 3, or instructions to send reports in any event.

[0043] At S452, the reporting section or a subsection thereof determines the propagation delay of each neighboring cell. In some embodiments, the reporting section determines the difference in propagation delay between the serving cell of the cellular network and the neighboring cell based on the orbit data and the geographical location of the terminal. In some embodiments, the determining section obtains the geographical location from a Global Positioning System (GPS) chip in the terminal, direct user input, or other manner not using the cellular network. In this manner, the reporting section makes the determination without providing the geographical location of the terminal to the cellular network or enabling the cellular network to obtain the geographical location of the terminal. In some embodiments, the reporting section does not make any determination other than the difference in propagation delay, such as in response to a reporting condition based on the difference in propagation delay. In some embodiments, the reporting section also reports the propagation delay variation, since the propagation delay may be different at the time the measurement signal reaches the terminal. In some embodiments, the serving cell is a non-terrestrial gateway that communicates with the terminal through a satellite. In some of these embodiments, the reporting section further determines the difference in propagation delay based on the geographical location of the non-terrestrial gateway.

[0044] In some embodiments, the reporting section uses the propagation delay to further determine whether the cell measurement signal arrives outside of a time frame defined by the cell measurement window specification, e.g., in response to a reporting condition based on such a determination. In some circumstances, the reporting section determines that the cell measurement signal arrives outside of a time frame defined by the cell measurement window specification.

[0045] At S454, the reporting section or subsection determines whether a reporting condition is met. In some embodiments, the reporting section references a reporting condition or a reporting instruction received from the serving cell along with the cell measurement window specification and the orbit data. In some embodiments, the reporting section references an internal reporting condition. In some embodiments where the reporting condition is a delay difference threshold, the reporting section determines for each neighboring cell whether the difference in propagation delay between the neighboring cell and the serving cell exceeds the delay difference threshold. If the reporting section determines that the reporting condition is met, the operational flow proceeds to S456 to send a report. If the reporting section determines that the reporting condition is not met, the operational flow ends without sending a report.

[0046] At S456, the report section or a subsection thereof sends a report to the serving cell. In some embodiments, the report is sent via RRC signaling. In some embodiments, the report section sends an indication in the report to the serving cell that the cell measurement signal is received outside a window defined by the cell measurement window specification. In some embodiments, the report includes an indication that the difference in propagation delay between the neighbor cell and the serving cell exceeds a delay difference threshold. In some embodiments, the report indicates that a reporting condition has not been met, such as when the serving cell instructs the terminal to send a report in any case.

[0047] 5 is an operational flow for compensating for satellite signal propagation delay variation in accordance with at least one embodiment of the present invention. In some embodiments, the operational flow provides a method for compensating for satellite signal propagation delay variation by a serving cell. In some embodiments, the operations are performed by a compensation section or a subsection thereof of the serving cell.

[0048] At S562, the compensation section or a subsection thereof modifies the cell measurement window specification. In some embodiments, the compensation section modifies at least one of the periodicity, duration, and offset. In some embodiments, the compensation section specifies an additional measurement window specification, such as an additional measurement window having a periodicity, duration, and offset. In some embodiments, the compensation section determines a modification that causes at least one measurement signal from all neighboring cells to reach all connected terminals within a time frame defined by the measurement window specification. In some embodiments, the compensation section determines a modification that causes at least one measurement signal from a majority of neighboring cells to reach a majority of connected terminals within a time frame defined by the measurement window specification. In some embodiments, the compensation section determines a separate modification for each neighboring cell, each communication channel, or each frequency band.

[0049] At S564, the compensation section or a subsection thereof determines the spectral efficiency of the cell measurement window specification modified at S562. In some embodiments, the spectral efficiency is a measurement of the amount of bandwidth consumed by the terminal for purposes related to establishing and maintaining network communications. In some embodiments where neighboring cells communicate on different frequencies than the serving cell, this directly relates to the amount of time taken to establish and maintain network communications, such as waiting for reception of a measurement signal. In some embodiments, the compensation section determines a separate spectral efficiency for each neighboring cell, each communication channel, or each frequency band.

[0050] At S566, the compensation section or a subsection thereof determines whether the spectral efficiency is acceptable. In some embodiments, the compensation section determines whether the spectral efficiency of the modified cell measurement window specification at S564 is acceptable by comparing the spectral efficiency to a spectral efficiency threshold. If the compensation section determines that the spectral efficiency of the modified cell measurement window specification at S564 is acceptable, the operational flow proceeds to transmission of the modified measurement window specification at S568. If the compensation section determines that the spectral efficiency of the modified cell measurement window specification at S564 is not acceptable, the operational flow proceeds to further modifying the measurement window specification at S562.

[0051] As the iterations of S562, S564, and S566 proceed, different modifications are tried until an acceptable spectral efficiency is achieved. In some embodiments where the spectral efficiency is compared to a spectral efficiency threshold, modifying the cell measurement window specification includes determining that the spectral efficiency of the modified cell measurement window specification exceeds the spectral efficiency threshold. In some embodiments, an algorithm or formula is used to determine a modification that has the greatest spectral efficiency. In some embodiments, an algorithm or formula is used to determine a modification of the cell measurement window specification that balances the spectral efficiency with the reception of the measurement signal. For example, a modification that allows at least one measurement signal from every neighboring cell to reach all connected terminals significantly reduces the spectral efficiency, especially in situations where there are many connected terminals.

[0052] In S568, the compensation section or a subsection thereof sends the cell measurement window specification modified in S562 to the connected terminal. In some embodiments, the modified cell measurement window specification is sent through RRC signaling. In some embodiments, the modified cell measurement window specification is substantially similar to that sent in S340 of FIG. 3, but without the orbit data and reporting conditions. In some embodiments, the modified cell measurement window specification includes a separate modification for each neighboring cell, each communication channel, or each frequency band.

[0053] FIG. 6 illustrates the relative timing between measurement windows and measurement signals with varying durations according to at least one embodiment of the present invention. Timeline 636 includes relative timing at times after t2 in FIG. 1B. Similar to the description of FIG. 2B, the measurement window 630A begins at time 632A after a 1 ms delay 633A because the total propagation delay between NTN gateway 110A (serving cell) and terminal 100 varies from about 5.1 ms to about 6.1 ms. The measurement signal 637A begins at time 638A with a 2.8 ms advance 639A because the total propagation delay between NTN gateway 110B (neighboring cell) and terminal 100 varies from about 13.4 ms to about 10.6 ms. However, instead of the measurement signal 637A arriving at terminal 100 outside of measurement window 630A, the cell measurement window specification has been modified by the serving cell to have a longer duration. Because of this modification, the measurement window 630A still begins at time 632A, but opens long enough to include time 638B when the measurement signal 637B arrives at the terminal 100.

[0054] In some embodiments, the measurement signal is advanced and the measurement window is delayed from the perspective of the terminal. The increase in the duration of the measurement window brings the subsequent measurement signal into the measurement window. In such a case, unless the sum of the advancement of the measurement signal and the delay of the measurement window is greater than half the periodicity, the increase in the duration used to capture the subsequent measurement signal reduces the spectral efficiency to 50% or less. In other words, the terminal consumes more than half the connection time or bandwidth just to maintain the network connection. A spectral efficiency of 50% or less may not be acceptable in many embodiments, and changing the cell measurement window specification to increase the duration has a higher probability of resulting in acceptable spectral efficiency in other situations. For example, in some embodiments where the measurement signal is delayed and the measurement window is advanced from the perspective of the terminal, changing the cell measurement window specification to increase the duration has a higher probability of resulting in acceptable spectral efficiency.

[0055] FIG. 7 illustrates the relative timing between measurement windows and measurement signals with modified offsets according to at least one embodiment of the present invention. Timeline 736 includes the relative timing at times after t2 in FIG. 1B. Similar to the description of FIG. 2B, measurement signal 737A starts at time 738A with an advance of 2.8 ms 739A because the total propagation delay between NTN gateway 110B (neighbor cell) and terminal 100 changes from about 13.4 ms to about 10.6 ms. The total propagation delay between NTN gateway 110A (serving cell) and terminal 100 changes from about 5.1 ms to about 6.1 ms. However, due to the modification, offset 731A has been introduced into the cell measurement window specification. As a result, measurement window 730A includes time 738B at which measurement signal 737B arrives at terminal 100 because measurement window 730A starts after offset 731A from time 732A.

[0056] In some embodiments, the measurement signal is advanced and the measurement window is delayed as seen by the terminal. The introduction of an offset in the measurement window, which is also a net increase in the offset from zero to a positive value, causes subsequent measurement signals to fall within the measurement window. Since the duration and periodicity of the measurement windows are constant and no other windows are introduced, the spectral efficiency is also constant. In other words, the terminal does not consume more connection time or bandwidth just to maintain a network connection than before the offset was introduced. An unchanged spectral efficiency after a change in the cell measurement window specification has a higher probability of being acceptable than a reduced spectral efficiency. However, in some embodiments where many terminals are connected to a serving cell with which many neighboring cells communicate via satellites, the relative timing between the measurement signals and the measurement windows as seen by different connected terminals is advanced and delayed by different amounts in different directions. Thus, a change in the cell measurement window specification to introduce or increase an offset has a lower probability of significantly increasing the amount of neighboring cells sending at least one measurement signal that reaches the connected terminal in embodiments with many terminals, many satellites, or both.

[0057] FIG. 8 is a diagram illustrating the relative timing between measurement windows and measurement signals with modified periodicity according to at least one embodiment of the present invention. Timeline 836 includes relative timing at times after t2 in FIG. 1B. Similar to the description of FIG. 2B, the measurement window 830A begins at time 832A after a 1 ms delay 833A because the total propagation delay between NTN gateway 110A (serving cell) and terminal 100 varies from about 5.1 ms to about 6.1 ms. The measurement signal 837A begins at time 838A with a 2.8 ms advance 839A because the total propagation delay between NTN gateway 110B (neighboring cell) and terminal 100 varies from about 13.4 ms to about 10.6 ms. However, instead of the measurement signal 837A arriving at terminal 100 outside a certain measurement window, the cell measurement window specification has been modified by the serving cell to have a shorter periodicity. Because of this change, measurement window 830A still begins at time 832A and ends before measurement signal 837B reaches terminal 100, but due to the reduction in periodicity, another measurement window 834B is open when measurement signal 837B reaches terminal 100.

[0058] In some embodiments, from the perspective of the terminal, the measurement signal is brought forward and the measurement window is delayed. A decrease in the periodicity of the measurement window, which is a substantial increase in the proportion of the measurement window with respect to time, reduces the spectral efficiency because the connected terminal spends more time waiting for the measurement signal. However, in some embodiments where many terminals are connected to a serving cell with which many neighboring cells communicate via satellites, a change in the cell measurement window specification to double the proportion of the measurement window has a higher probability of significantly increasing the amount of neighboring cells sending at least one measurement signal that reaches the connected terminal than a change that does not increase the amount of time the connected terminal spends waiting for the measurement signal.

[0059] FIG. 9 illustrates the relative timing between an initially configured measurement window, an additional measurement window, and a measurement signal according to at least one embodiment of the present invention. Timeline 936 includes the relative timing at times after t2 in FIG. 1B. Similar to the description of FIG. 2B, the measurement window 930A begins at time 932A after a 1 ms delay 933A because the total propagation delay between NTN gateway 110A (serving cell) and terminal 100 varies from about 5.1 ms to about 6.1 ms. The measurement signal 937A begins at time 938A with a 2.8 ms advance 939A because the total propagation delay between NTN gateway 110B (neighboring cell) and terminal 100 varies from about 13.4 ms to about 10.6 ms. However, instead of the measurement signal 937A arriving at terminal 100 outside of a measurement window, the cell measurement window specification has been modified by the serving cell to have an additional measurement window specification. In some embodiments, the additional window measurement specification includes a periodicity, duration, and offset having different values ​​in addition to the periodicity, duration, and offset of the initial window measurement specification. Because of this change, the measurement window 930A still begins at time 932A and ends before the measurement signal 937B reaches the terminal 100, but the additional window measurement specification causes another measurement window 935 to be open when the measurement signal 937B reaches the terminal 100.

[0060] In some embodiments, from the perspective of the terminal, the measurement signal is brought forward and the measurement window is delayed. An additional window measurement specification that effectively adds a measurement window reduces the spectral efficiency since the connected terminal spends more time waiting for the measurement signal. However, in some embodiments where many terminals are connected to a serving cell with which many neighboring cells communicate via satellites, a change in the cell measurement window specification to add a measurement window has a higher likelihood of significantly increasing the amount of neighboring cells sending at least one measurement signal that reaches the connected terminal than a change that does not increase the amount of time the connected terminal spends waiting for the measurement signal.

[0061] 10 is an operational flow for further compensating for satellite signal propagation delay variation in accordance with at least one embodiment of the present invention. In some embodiments, the operational flow provides a method for compensating for satellite signal propagation delay variation by a terminal connected to a serving cell. In some embodiments, the operations are performed by a compensation section or a subsection thereof of the terminal.

[0062] At S1070, the compensation section or a subsection thereof receives a modified window measurement specification from the serving cell. In some embodiments, the modified window measurement specification is received through RRC signaling. In some embodiments, the modified cell measurement window specification is modified as described in S562 of FIG. 5.

[0063] In S1072, the compensation section or subsection determines whether any of the neighboring cell measurement signals arrive outside the measurement window defined by the modified cell measurement window specification. Some of the connected terminals determine that the modified cell measurement window specification still results in one or more neighboring cell measurement signals arriving outside the measurement window because modifying the cell measurement window specification to ensure that at least one measurement signal from all neighboring cells arrives at all connected terminals would result in unacceptable spectral efficiency in some circumstances. If the compensation section determines that one or more neighboring cell measurement signals arrive outside the measurement window, the operation flow proceeds to individual measurement window configuration in S1074. If the compensation section determines that at least one measurement signal from all neighboring cells arrives within the measurement window, the operation flow ends without performing individual measurement configuration.

[0064] In S1074, the compensation section or a subsection thereof configures an individual measurement window. In some embodiments, the compensation section configures an individual measurement window specification that defines one or more time frames during which only the individual terminal waits for the arrival of a measurement signal. During the time frames defined by the individual measurement window specification, the serving does not communicate with the terminal but continues to communicate with other terminals. In this way, the individual measurement window specification results in a much smaller reduction in spectral efficiency for the cell and other terminals than a terminal configured with an individual measurement window specification. In some embodiments in which the measurement signal is advanced and the measurement window is delayed from the terminal's perspective, the compensation section configures an individual measurement window similar to the measurement window 935 of FIG. 9. In some embodiments, the individual measurement window specification includes a periodicity, duration, and offset that may be configured to receive multiple measurement signals from different neighboring cells. In some embodiments, the individual measurement window specification only includes a start time and duration, resulting in a single individual measurement window that has a higher probability of resulting in a higher spectral efficiency in embodiments that result in multiple individual measurement windows but may allow for the reception of fewer measurement signals.

[0065] At S1076, the compensation section or a subsection thereof sends a report of the individual measurement window specifications to the serving cell. In some embodiments, the individual measurement window specifications are sent through RCC signaling.

[0066] At S1078, the compensation section or a subsection thereof receives a confirmation from the serving cell. In some embodiments, the confirmation received from the serving cell confirms that the serving cell will not communicate with the terminal during any time frame defined by the individual measurement window specification. In other words, the serving cell provides a measurement gap for the terminal that coincides with any time frame defined by the individual measurement window specification. In some embodiments, the confirmation is received through RCC signaling.

[0067] In some embodiments, the serving cell may perform operations S1072, S1074, S1076, and S1078. In some of these embodiments, the computational load on the serving cell increases, leading to the serving cell utilizing more computational resources. In some of these embodiments, the terminal sends more detailed information regarding the measurement window and the relative timing of the measurement signals to the serving cell, such as during transmission of a propagation delay report similar to operation S456 of FIG. 4. In some of these embodiments, the serving cell sends individual cell measurement window specifications to each terminal during transmission of modified cell measurement window specifications similar to operation S568 of FIG. 5.

[0068] 11 is a further operational flow for compensating for satellite signal propagation delay variation in accordance with at least one embodiment of the present invention. In some embodiments, the operational flow provides a method for compensating for satellite signal propagation delay variation by a terminal connected to a serving cell. In this embodiment, the operations are performed by a system including a serving cell 1110 and a terminal 1100 connected to the serving cell 1110. In some embodiments, transmission between the serving cell 1110 and the terminal 1100 is performed through RRC signaling.

[0069] The serving cell 1110 sends the measurement window specification and orbit data 1140 to the terminal 1100. In some embodiments, the serving cell 1110 also sends reporting conditions. The terminal 1100 receives the window specification and orbit data 1140 and determines the delay propagation for each cell that communicates with the terminal 1100 through a satellite. In response to determining a significant difference in the delay propagation between the serving cell 1110 and any neighboring cells, or in response to determining that other reporting conditions specified by the serving cell are met, the terminal 1100 sends a delay propagation report 1156 to the serving cell. In some embodiments, the delay propagation report includes more detailed information than the propagation delay value, such as the measurement window and the relative timing of the measurement signals as seen by the terminal 1100. The serving cell 1110 receives the delay propagation report 1156 and modifies the cell measurement window specification in response to the delay propagation report 1156 including an indication that the measurement signals of one or more neighboring cells will not reach the terminal 1100 during any time frame defined by the cell measurement window specification. In some embodiments, the serving cell 1110 attempts to modify the cell measurement window specification such that at least one measurement signal from all neighboring cells arrives within the measurement window as seen by the terminal 1100, but no modification achieves this with acceptable spectral efficiency. The serving cell 1110 sends a modified cell measurement window specification 1168 to the terminal 1100 that causes measurement signals from all neighboring cells not to arrive within the measurement window as seen by the terminal 1100. In response to receiving the modified cell measurement window specification 1168, the terminal 1100 configures an individual cell measurement window specification 1176 to define a measurement window for receiving at least one measurement signal of any neighboring cell whose measurement signal does not arrive within any time frame defined by the modified cell measurement window specification 1168. The terminal 1100 sends the individual cell measurement window specification 1176 to the serving cell 1110. The serving cell 1110 responds by sending a synchronous measurement gap 1169 that confirms that the serving cell 1110 provides measurement gaps that are synchronous with the time frame defined by the individual cell measurement window specification 1176 .

[0070] In some embodiments of the system, the serving cell 1110 does not send trajectory data, does not collect propagation delay reports, or does not receive individual cell measurement window specifications. Instead, in these embodiments, each connected terminal, such as the terminal 1100, sends its geographical location to the serving cell 1110. In some of these embodiments, the serving cell 1110 makes all decisions based on this information, including determining whether a change to the cell measurement window specification is necessary, determining changes to the cell measurement window specification, and determining the individual cell measurement window specification. In such embodiments, the serving cell 1110 utilizes more computational resources instead of the connected terminal, resulting in more energy efficiency for the connected terminal. However, some embodiments in which the connected terminal performs more decisions balance energy consumption more than some embodiments in which the serving cell 1110 performs all decisions. Also, in some embodiments in which the terminal 1100 is in a geographical area where network collection of individual geographical locations is prohibited, the terminal 1100 may not have the capability to send its geographical location to the serving cell 1110. Furthermore, in some embodiments where only connected terminals send geographical locations, terminal-determined reporting conditions cannot be used that would require all terminals to send geographical locations all the time, not just when delay becomes significant or exceeds a threshold.

[0071] 12 is a block diagram of an example hardware configuration of a serving cell for satellite signal propagation delay variation compensation in accordance with at least one embodiment of the present invention. The example hardware configuration includes a serving cell 1210A that communicates with a terminal 1200 and neighboring cells 1210B, 1210C, 1210D, and 1210E through a cellular network 1226.

[0072] The serving cell 1210A includes a controller 1212, a storage unit 1214, and a communication interface 1216. In some embodiments, the controller 1212 and the storage unit 1214 are part of a client computer, a computer system including multiple computers, or a server mainframe that directly interfaces with the serving cell 1210A.

[0073] In some embodiments, the controller 1212 is a processor or programmable circuit that executes instructions that cause the processor or programmable circuit to perform operations according to the instructions. In some embodiments, the controller 1212 is an analog or digital programmable circuit, or any combination thereof. In some embodiments, the controller 1212 is comprised of physically separate storage or circuitry that interacts through communication. In some embodiments, the storage unit 1214 is a non-volatile computer readable medium that can store executable and non-executable data for access by the controller 1212 during execution of instructions. The communication interface 1216 transmits and receives data to and from the network 1226.

[0074] The controller 1212 includes a detection section 1280 and a compensation section 1282. The storage unit 1214 includes orbit data 1284, cell measurement window specifications 1286, and compensation parameters 1288.

[0075] The detection section 1280 is a circuit or instruction of the controller 1212 that detects whether an attached terminal, such as terminal 1200, does not have measurement signals from neighboring cells, such as neighboring cells 1210B, 1210C, 1210D, and 1210E, that reach the attached terminal during a time frame defined by the cell measurement window specification. In some embodiments, the detection section 1280 utilizes information in the storage unit 1214, such as the trajectory data 1284 and the cell measurement window specification 1286. The detection section 1280 may include subsections for performing additional functions as described in the preceding flow charts. Such subsections may be represented by names associated with their functions.

[0076] The compensation section 1282 is a circuit or instruction of the controller 1212 that performs satellite signal propagation delay variation compensation. In some embodiments, the compensation section 1282 modifies the cell measurement window specification to increase reception of neighbor cell measurement signals with acceptable spectral efficiency. While performing the compensation, in some embodiments, the compensation section 1282 utilizes information in the storage unit 1214, such as the cell measurement window specification 1286 and the compensation parameters 1288. The compensation section 1282 may include subsections for performing additional functions as described in the preceding flow charts. Such subsections may be represented by names associated with their functions.

[0077] In other embodiments, the serving cell includes or is in direct communication with other devices capable of processing logical functions to perform the operations herein. In some embodiments, the controller and storage unit are not entirely separate devices, but share circuitry or one or more computer-readable media. In some embodiments, the storage unit may be a hard drive that stores both computer-executable instructions and data accessed by the controller, and the controller may be a combination of a central processing unit (CPU) and RAM into which all or a portion of the computer-executable instructions may be copied for execution by the CPU during performance of the operations herein.

[0078] In embodiments in which the serving cell utilizes a computer to perform the operations herein, a program installed on the computer causes the computer to function as or perform the operations associated with the serving cell of the embodiments described herein. In some embodiments, such a program may be executed by a processor to cause the computer to perform certain operations associated with some or all of the blocks of the flowcharts and block diagrams described herein.

[0079] 13 is a block diagram of an exemplary hardware configuration of a terminal for satellite signal propagation delay variation compensation in accordance with at least one embodiment of the present invention. The exemplary hardware configuration includes a terminal 1300 in communication with a serving cell 1310A and neighboring cells 1310B, 1310C, 1310D, and 1310E through a cellular network 1326.

[0080] The terminal 1300 includes a controller 1302, a storage unit 1304, and a communication interface 1306. In some embodiments, the terminal 1300 is a mobile phone, a smartphone, a tablet, a notebook computer, or any other device with a cellular network communication interface.

[0081] In some embodiments, the controller 1302 is a processor or programmable circuit that executes instructions that cause the processor or programmable circuit to perform operations according to the instructions. In some embodiments, the controller 1302 is an analog or digital programmable circuit, or any combination thereof. In some embodiments, the controller 1302 is comprised of physically separate storage or circuitry that interacts through communication. In some embodiments, the storage unit 1304 is a non-volatile computer readable medium that can store executable and non-executable data for access by the controller 1302 during execution of instructions. The communication interface 1306 transmits and receives data to and from the network 1326.

[0082] The controller 1302 includes a report section 1390 and a compensation section 1392. The storage unit 1304 includes orbit data 1394, cell measurement window specifications 1396, and compensation parameters 1398.

[0083] The report section 1390 is circuitry or instructions in the controller 1302 that reports whether measurement signals of any neighboring cells, such as neighboring cells 1310B, 1310C, 1310D, and 1310E, do not reach the terminal 1300 during a time frame defined by the cell measurement window specification. In some embodiments, the report section 1390 utilizes information in the storage unit 1304, such as the trajectory data 1394 and the cell measurement window specification 1396. The report section 1390 may include subsections for performing additional functions as described in the preceding flow charts. Such subsections may be represented by names associated with their functions.

[0084] The compensation section 1392 is a circuit or instruction of the controller 1302 that performs satellite signal propagation delay variation compensation. In some embodiments, the compensation section 1392 configures individual cell measurement window specifications to receive measurement signals of any neighboring cells not received by the cell measurement window specifications. While performing the compensation, in some embodiments, the compensation section 1392 utilizes information in the storage unit 1304, such as the cell measurement window specifications 1396 and the compensation parameters 1398. The compensation section 1392 may include subsections for performing additional functions as described in the preceding flow charts. Such subsections may be represented by names associated with their functions.

[0085] In other embodiments, the terminal includes other devices capable of processing logical functions to perform the operations herein. In some embodiments, the controller and the storage unit are not entirely separate devices, but share circuitry or one or more computer-readable media. In some embodiments, the storage unit may be a hard drive that stores both computer-executable instructions and data accessed by the controller, and the controller may be a combination of a central processing unit (CPU) and RAM into which all or a portion of the computer-executable instructions may be copied for execution by the CPU during performance of the operations herein.

[0086] In embodiments in which a terminal utilizes a computer processor to perform the operations herein, a program installed on the terminal causes the terminal to function as or perform the operations of the embodiments described herein. In some embodiments, such a program may be executed by the computer processor to cause the terminal to perform certain operations associated with some or all of the blocks of the flowcharts and block diagrams described herein.

[0087] Various embodiments of the present invention are described with reference to flow charts and block diagrams, whose blocks may represent (1) processing steps where operations are performed or (2) sections of a controller responsible for carrying out the operations. Particular steps and sections are implemented by dedicated circuitry, programmable circuitry provided with computer readable instructions stored on a computer readable medium, and / or a processor provided with computer readable instructions stored on a computer readable medium. In some embodiments, the dedicated circuitry includes digital and / or analog hardware circuitry and may include integrated circuits (ICs) and / or discrete circuits. In some embodiments, the programmable circuitry includes reconfigurable hardware circuitry comprising logical AND, OR, XOR, NAND, NOR, and other logic operations, flip-flops, registers, memory elements, and the like, such as field programmable gate arrays (FPGAs), programmable logic arrays (PLAs), and the like.

[0088] Various embodiments of the invention include systems, methods, and / or computer program products. In some embodiments, the computer program product includes a computer-readable storage medium (or media) having computer-readable program instructions for causing a processor to perform aspects of the invention.

[0089] In some embodiments, a computer-readable storage medium includes a tangible device that can hold and store instructions for use by an instruction execution device. In some embodiments, a computer-readable storage medium includes, but is not limited to, for example, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the above. A non-exhaustive list of more specific examples of computer-readable storage media includes the following: portable computer diskettes, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROMs or flash memories), static random access memories (SRAMs), portable compact disk read-only memories (CD-ROMs), digital versatile disks (DVDs), memory sticks, floppy disks, punch cards or mechanically encoded devices such as raised structures in grooves with instructions recorded therein, and any suitable combination of the above. A computer-readable storage medium, as used herein, is not to be construed as a transitory signal per se, such as an electric wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a wave guide or other transmission medium (e.g., light pulses passing through a fiber optic cable), or an electrical signal sent through a wire.

[0090] In some embodiments, the computer readable program instructions described herein can be downloaded from a computer readable storage medium to each computing / processing device, or can be downloaded to an external computer or storage device over a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. In some embodiments, the network may include copper transmission cables, optical transmission fiber, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer readable program instructions from the network and transfers the computer readable program instructions to a computer readable storage medium within each computing / processing device for storage.

[0091] In some embodiments, the computer readable program instructions for performing the operations described above are source or object code written in any combination of one or more programming languages, including assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state setting data, or traditional procedural programming languages, such as Smalltalk, object oriented programming languages ​​such as C++, and the "C" programming language or similar programming languages. In some embodiments, the computer readable program instructions execute entirely on the user's computer, partially on the user's computer as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In some embodiments, in the latter scenario, the remote computer is connected to the user's computer through any type of network, including a local area network (LAN) or wide area network (WAN), or the connection may be made to an external computer (e.g., through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), executes the computer readable program instructions by utilizing state information of the computer readable program instructions to customize the electronic circuitry to perform aspects of the invention.

[0092] Although the embodiments of the present invention have been described, the technical scope of the claimed subject matter is not limited to the above-described embodiments. It is obvious to those skilled in the art that various modifications and improvements can be made to the above-described embodiments. It is also obvious from the scope of the claims that the embodiments to which such modifications or improvements have been made are included in the technical scope of the invention.

[0093] The operations, procedures, steps, and stages of each process performed by the apparatus, systems, programs, and methods illustrated in the claims, embodiments, or figures may be performed in any order, unless the order is indicated by "earlier than," "before," etc., and unless output from a previous process is used in a later process. The use of phrases such as "first" or "next" in the claims, embodiments, or figures to describe a process flow does not necessarily imply that the processes must be performed in that order.

[0094] In accordance with at least one embodiment of the present invention, satellite signal propagation delay variations can be compensated for by sending to the terminal orbital data and cell measurement window specifications for satellites providing communication with the terminal for a serving cell and / or a neighboring cell, receiving an indication from the terminal that a cell measurement signal will arrive at the terminal outside a time frame defined by the cell measurement window specification, modifying the cell measurement window specification based on a difference in propagation delay between the serving cell defining the cell measurement window specification and the neighboring cell sending the cell measurement signal, such that the cell measurement signal arrives at the terminal within the time frame defined by the cell measurement window specification, and sending the modified cell measurement window specification to the terminal.

[0095] Some embodiments include instructions in a computer program, a method performed by a processor executing the instructions of the computer program, and a serving cell performing the method. In some embodiments, the serving cell includes a controller including circuitry configured to perform operations in the instructions.

[0096] In accordance with at least one embodiment of the present invention, satellite signal propagation delay variations can be compensated for by receiving satellite orbit data and a cell measurement window specification from a serving cell of a cellular network, determining whether a cell measurement signal sent from a neighboring cell is received outside a time frame defined by the cell measurement window specification based on a difference in propagation delay between the serving cell and the neighboring cell, and sending an indication to the serving cell that the cell measurement signal is received outside the window defined by the cell measurement window specification.

[0097] Some embodiments include instructions in a computer program, a method performed by a processor executing the instructions of the computer program, and a terminal for performing the method. In some embodiments, the terminal includes a controller including circuitry configured to perform operations in the instructions.

[0098] The foregoing has outlined certain features of certain embodiments so that those skilled in the art may better understand aspects of the present disclosure. Those skilled in the art will appreciate that this disclosure may be utilized as a basis for designing or modifying other processes and structures to carry out the same purposes and / or achieve the same advantages as the embodiments disclosed herein. Those skilled in the art will also recognize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and will recognize that various changes, substitutions, and alterations may be made without departing from the spirit and scope of the present disclosure.

[0099] This application claims priority to U.S. Provisional Patent Application No. 63 / 137,916, filed January 15, 2021, and U.S. Provisional Patent Application No. 63 / 140,578, filed January 22, 2021, each of which is described below and incorporated by reference in its entirety.

[0100] U.S. Provisional Patent Application No. 63 / 137,916

[0101] 3GPP TSG-RAN WG2 Meeting #113-e

[0102] E-Meeting: January 25th ~ February 5th, 2021

[0103] Agenda item: 8.10.3.3

[0104] Source: Rakuten Mobile

[0105] Title: SMTC and measurement gap configuration for NTN

[0106] Document purpose: Discussion and decision

[0107] 1. Introduction The UE measurement challenges posed by differences in propagation delay between satellites remain a topic of discussion. The following agreements were reached during the offline discussions

[0106] [NTN] SMTC and GAP (2nd round): agreement: 1. Proposal 1: SMTC and gap configuration in NTN are configured based on the timing of PCell. 2. The RAN2 understands that, similar to the principle in the TN, the UE is not forced to detect SSB bursts outside the corresponding SMTC window configured in the NTN. 3. Similar to the TN, the UE, together with the network in the NTN, should have a consistent understanding of measurement gaps to avoid unsynchronized behavior between the UE and the network. This contribution solves an open issue and proposes a solution for SMTC window / gap configuration for SSB / CSI-RS measurements of neighboring cells (with varying delay) for cases when the network does not have accurate UE location information.

[0108] 2. Discussion

[0109] 2.1. Comments on the existing proposal (R2-2010795) First, we would like to offer our perspective on existing proposals that require discussion. Proposal 2-1: RAN2 understands that the impact of delay differences between satellites on the SMTC configuration should be addressed in NTN. FFS: Is improvement of the SMTC configuration necessary in NTN? As described later in R2-2010795, the SMTC window should be refined for NTN systems since it needs to follow the delay variation between serving and neighboring cells / satellites. "In the normal case of TN system, the SSB burst signal generated by the neighboring cell is always detectable within the corresponding SMTC window configured via the serving cell. Outside the corresponding SMTC window configured, there is no need for the UE to measure the SSB burst signal. However, for NTN system, the analysis shows that the SSB burst signal generated by the neighboring cell may be outside the corresponding SMTC window configured via the serving satellite. If the UE has the ability to acquire the propagation delay difference between the serving and neighboring satellites, the UE can still know when to detect the actual SSB burst signal generated by the neighboring cell even if the SSB burst signal is outside the corresponding SMTC window configured. If RAN2 does not want to refine the SMTC configuration for NTN, the UE should be allowed to search for the SSB burst signal generated by the neighboring cell even if it is outside the corresponding SMTC window configured."

[0110] Proposal 1: The SMTC window should be improved for NTN systems since it needs to follow the delay variation between serving and neighboring cells / satellites. Proposal 2-2: RAN2 will first identify the scenarios and discuss the severity of the impacts before starting to improve the SMTC configuration in NTN.

[0111] Proposal 2: The improvement of SMTC configuration in NTN should be taken up in detail. Proposal 4: Due to the SMTC window configuration in NTN, RAN2 cannot assume that the network always has accurate location information of the UE. Due to security and privacy concerns, national regulatory bodies may prohibit network providers from obtaining the UE's location, even if precise location can be obtained by satellite. Thus, it may not be possible to assume that all networks have the exact location of the UE at all times.

[0112] Proposal 3: Agree with Proposal 4 in R2-2010795: Due to the SMTC window configuration in NTN, RAN2 cannot assume that the network always has accurate location information of the UE. Proposal 6-1: RAN2 understands that the impact of delay differences between satellites on the measurement gap configuration should be addressed in NTN. FFS: Is an improvement in the measurement gap configuration necessary in NTN? If R2-2010795 proves that an improvement in the measurement gap configuration is necessary in the NTN system, the following options may be considered: Option 1: Extend the length of the measurement gap to ensure that its length is equal to or greater than the SSB periodicity. Option 2: Reuse current signaling for measurement gap configuration (i.e. configure measurement gaps per frequency) and the timing of the configured measurement gaps refers to the timing at the satellite or NTN GW. With the configured measurement gaps, it is up to the UE / NW to derive the measurement gaps at the UE side based on its location and the orbits of the candidate satellites. Since the actual timing of the SMTC windows at the UE side for cells in other satellites changes over time based on the satellite movement, the NW needs to derive the actual timing of the measurement gaps at the UE side based on the UE location and the orbits of the candidate satellites. Note: In this example, the measurement gaps are maintained per satellite. Option 3: Configure multiple measurement gaps per frequency, and the timing of the configured measurement gaps refers to the timing of the PCell on the UE side. Option 4: Increase the length of the measurement gap based on the maximum propagation delay difference between the serving and nearby satellites to prevent the UE from missing the SSB bursts of nearby satellites. Option 5: Apply measurement gap timing advance periodically to detect all possible SSBs. For option 1, extending the measurement gap period should not be discussed as a priority since data cannot be scheduled during the measurement gap period and extending the measurement gap period reduces the spectrum efficiency. A method is proposed for determining measurement gaps for a UE even when the gNB does not have UE location information, which can also be effectively used for other options such as option 2 and option 3. Assumptions: 1) Based on Proposal 6-1 Option 2: "It is up to the UE / NW to derive the measurement gaps at the UE side based on its location and the orbits of the candidate satellites. Since the actual timing of the SMTC windows at the UE side for cells in other satellites changes over time based on the satellite movement, the NW needs to derive the actual timing of the measurement gaps at the UE side based on the UE location and the orbits of the candidate satellites. Note: In this example, the measurement gaps are maintained per satellite." 2) As agreed at RAN1 Meeting #103, it can be assumed that the UE always has its location information via GNSS.

[0113] Proposal 4: The following method is agreed upon to determine measurement gaps for a UE even when the gNB does not have the UE location information. 1. The gNB needs to send the trajectories of neighboring cells to the UE in RRC signaling as part of MeasObjectNR RRC. 2. The UE can calculate the propagation delay of nearby cells / satellites based on its location and nearby satellite orbits. 3. If the UE detects a significant RTD (> “X” ms) between the serving and nearby satellites, it informs the gNB via an RRC message. 4. The gNB configures measurement gaps for each neighbor or extends the measurement gaps based on UE feedback. 5. The UE shall calculate the RTD for the neighbors after a preconfigured period “Y” indicated by the gNB, and if the RTD change for the neighbors is greater than “Z”, report the RTD to the serving cell via an RRC message. Proposal 6-2: RAN2 will first identify scenarios and discuss the severity of impacts before starting to refine the measurement gap configuration in NTN. The severity of the impact can be evaluated in RAN2, but it should be agreed that a solution is required to provide appropriate configuration of measurement gaps / SMTC to detect SSB / CSI-RS.

[0114] Proposal 5: A solution is required to provide a proper configuration of measurement gaps / SMTC for detecting SSB / CSI-RS. Proposal 7: Due to the measurement gap configuration (20 / 5) in NTN, RAN2 cannot assume that the network always has accurate location information of the UE.

[0115] Proposal 6: Agree with Proposal 7 in R2-2010795: Due to the measurement gap configuration in NTN, RAN2 cannot assume that the network always has accurate location information of the UE. Proposal 8: More discussion is needed in RAN2 before sending LS to RAN4 to clarify the requirement for measurement SMTC / gap configuration (16 / 6) in NTN.

[0116] Proposal 7: Agree with Proposal 8 in R2-2010795: More discussion is needed in RAN2 before sending LS to RAN4 to clarify requirements for measurement SMTC / Gap configuration in NTN.

[0117] U.S. Provisional Patent Application No. 63 / 140,578

[0118] 1. Introduction The challenges for User Equipment (UE) measurements caused by different propagation delays between satellites remain a topic of discussion. During the offline discussions

[0106] [NTN] Synchronization Signal (SS) / Physical Broadcast Channel (PBCH) based Measurement Timing Configuration (SMTC) and Gap (2nd round), the following agreements were reached: agreement: 1. Proposal 1: The SMTC and gap configuration in NTN are configured based on the timing of the primary cell (PCell). 2. The Radio Access Network 2 (RAN2) understands that, similar to the principle in the Terrestrial Network (TN), the UE is not forced to detect SSB bursts outside the corresponding SMTC window configured in the NTN. 3. Similar to the TN, the UE, together with the network in the NTN, should have a consistent understanding of measurement gaps to avoid unsynchronized behavior between the UE and the network. 4. In Rel-17, the New Radio (NR) NTN supports UEs that can obtain at least one of their position, time reference, and frequency based on its Global Navigation Satellite System (GNSS) implementation. Radio Access Network 1 (RAN1) 102e.

[0119] background: During handover of a UE from a serving cell to a neighboring cell, the UE needs to perform measurements to properly synchronize and connect to the neighboring cell. In some embodiments, such as when the serving cell and the neighboring cell operate on different carrier frequencies, the UE cannot simultaneously transmit and receive with the serving cell and synchronize and connect to the neighboring cell. Thus, in some wireless technologies, such as 5G NR, a measurement gap is a time period provided by the network that allows the UE to perform appropriate measurements with the neighboring cell to synchronize and connect to the neighboring cell. In some embodiments, such as 5G NR, the UE performs measurements on the SSBs of the neighboring cells during the measurement gap. In some embodiments, the network provides the timing of the neighboring cell SSBs using SMTC. In connected mode, the UE is provided by the network with an SMTC that defines a window of time during which the UE can perform measurements on neighboring cell SSBs. The SMTC is configured by a window periodicity, an offset, and a window duration, and is based on the timing of the primary cell (PCell) (also referred to as the "serving cell"). The window periodicity (measurement gap) can be configured as 5, 10, 20, 40, 80, or 160 ms, and the SMTC window duration can be configured as 1, 2, 3, 4, or 5 ms. Figure 1 below (Figure 14 in this application) illustrates an SMTC / measurement gap configuration according to some embodiments. In some embodiments, based on the UE capabilities, a measurement gap is configured if the UE cannot measure SSB for neighboring cells and monitor the serving cell simultaneously. In some embodiments, the serving cell does not schedule the UE during the measurement gap. The network ensures that SSB from neighboring cells is sent during the measurement gap so that the UE can measure the strength and quality of the neighboring cell SSB. In some embodiments, the UE needs to generate neighboring cell measurements at appropriate intervals to meet the requirements in TS 38.133, which is incorporated herein by reference in its entirety. Figure 2 (Figure 15 in this application) illustrates details of the measurement gap / SMTC configuration according to some embodiments.

[0120] Exemplary problems solved by the disclosure: In a Low Earth Orbit (LEO) NTN scenario, the propagation delay for the neighbor cell SSB to reach the UE constantly changes due to satellite movement. Therefore, the SMTC / measurement gap configuration needs to take this delay variation into account. The delay can be different based on the relative location of the UE on the ground, as illustrated below for User Equipment 1 (UE1) and User Equipment 2 (UE2). The window for SSB measurements should take into account all possible neighbor cell SSB delays, i.e., all possible delays between UE1 and UE2. The neighbor cell delay also changes over time for the UE as the satellite moves. In Figure 3 (Figure 16 in this application), the propagation delay encountered by the UE at the UE1 position changes to the propagation delay encountered by the UE at the UE2 position as the satellite beam moves on the ground. Due to this movement, the neighbor cell SSB timing measured by the UE also drifts. Note that the UE also moves, but the effect of the UE movement is mostly negligible since the effect is negligible compared to the speed of the satellite. Figure 4 below (Figure 17 in this application) illustrates the variation of propagation delay in a LEO NTN according to some embodiments. If the UE cannot perform SSB measurements on neighboring cells, the UE may not be able to report neighboring cell measurement results or perform handover condition evaluation. This will negatively impact handover performance and cause the UE to disconnect unexpectedly. Handover is crucial in LEO NTN scenarios due to satellite movement. In NTN, the UE is exposed to different propagation delays between the serving cell and neighboring cells. The SMTC configuration and SSB reception window may be different for different cells (e.g., between cells of satellites at different locations, as shown in FIG. 4). The UE may be configured with only one measurement gap, and the maximum measurement gap length is 6 ms. Thus, for neighboring cells of different frequencies or the same frequency, the configured measurement gap may not work, and the UE may not be able to acquire the SSB of the neighboring cells for radio resource management (RRM) measurements, as shown in FIG. 5 (FIG. 18 in this application). A basic scenario is illustrated where SAT1 [LEO600] currently serves the UE and SAT2 [LEO1500] is a potential target neighbor cell. In the considered scenario, SAT1 is moving away from the UE and SAT2, potentially on a different orbit, is moving towards the UE. The propagation delay between SAT1 and the UE is denoted as dSAT1-UE(t) (i.e., a function of time t) and the delay between SAT2 and the UE is denoted as dSAT2-UE(t). Note that in a transparent satellite scenario, the propagation delay also depends on the relative position of the terrestrial NTN gateway. In this example, SAT1 is moving towards the connected NTN-GW1 and SAT2 is moving towards the connected NTN-GW2. The respective propagation delays between the satellites and the gateways are dSAT1-GW1(t) and dSAT1-GW2(t). Due to the movement of the satellites, the propagation delay varies with time. Figure 19 provides a numerical example based on the estimated elevation angles between UE and SAT1 / SAT2 and between NTN-GW1 and SAT1, and NTN-GW2 and SAT2. In this example, the LEO satellites are assumed to fly at an altitude of 600 km. Due to the recent RAN2 agreements listed in the introduction, the UE timing is based on the serving cell (SAT1 in this example), so the UE is subject to SSB drift from a neighboring cell (SAT2). Based on the assumed geometries of the scenarios in Figure 4 and Table 1, the propagation delay between NTN-GW1 and the UE varies from 5.1 ms to 6.1 ms, and the propagation delay between NTN-GW2 and the UE decreases from about 13.4 ms to about 10.6 ms. Thus, the delay difference between the two connections observed by the UE varies from 18.5 ms at T1 to 16.7 ms at T2. The maximum SMTC window duration is 5 subframes, and depending on the initial position in time of the SMTC window of SAT2's SSB, the statically configured window may not be able to accommodate the variations in propagation delay. Since it was agreed in RAN2 that the UE is not required to monitor SSB outside the configured SMTC window, measurements on neighboring cells are challenging with the current SMTC configuration options, at least for (semi-)static SMTC configurations. Due to the delay difference, it is essential to dynamically adjust the gap configuration. The SMTC window follows the dynamically determined gap configuration. The challenges are even more pronounced in the LEO and geostationary orbit (GEO) cases. 38.811:See Figure 20.

[0121] 2. Discussion

[0122] 2.1. Comments on the existing proposal (R2-2010795) We first provide some perspective on existing proposals that require discussion, which are incorporated herein by reference in their entirety. Proposal 2-1: RAN2 understands that the impact of delay differences between satellites on the SMTC configuration should be addressed in NTN. FFS: Is improvement of the SMTC configuration necessary in NTN? As described later in R2-2010795, the SMTC window should be refined for NTN systems since it needs to follow the delay variation between serving and neighboring cells / satellites. "In the normal case of TN system, the SSB burst signal generated by the neighboring cell is always detectable within the corresponding SMTC window configured via the serving cell. Outside the corresponding SMTC window configured, there is no need for the UE to measure the SSB burst signal. However, for NTN system, the analysis shows that the SSB burst signal generated by the neighboring cell may be outside the corresponding SMTC window configured via the serving satellite. If the UE has the ability to acquire the propagation delay difference between the serving and neighboring satellites, the UE can still know when to detect the actual SSB burst signal generated by the neighboring cell even if the SSB burst signal is outside the corresponding SMTC window configured. If RAN2 does not want to refine the SMTC configuration for NTN, the UE should be allowed to search for the SSB burst signal generated by the neighboring cell even if it is outside the corresponding SMTC window configured." Assumptions: 1) Based on Proposal 6-1 Option 2: "It is up to the UE / Network (NW) to derive the measurement gaps at the UE side based on its location and the orbits of the candidate satellites. Since the actual timing of the SMTC windows at the UE side for cells in other satellites changes over time based on the satellite movement, the NW needs to derive the actual timing of the measurement gaps at the UE side based on the UE location and the orbits of the candidate satellites. Note: In this example, the measurement gaps are maintained per satellite." 2) As agreed at RAN1 Meeting #103, it can be assumed that the UE always has its location information via GNSS. Exemplary embodiment: A method for determining measurement gaps for a UE even when a 5G radio node (gNB) does not have UE location information 1. The gNB sends the trajectories of neighboring cells to the UE in Radio Resource Control (RRC) signaling as part of MeasObjectNR RRC. 2. The UE can calculate the propagation delay of nearby cells / satellites based on the UE position and nearby satellite orbits. 3. If the UE detects a significant round trip delay (RTD) between the serving and nearby satellites (>“Delta RTD” ms), it informs the gNB via an RRC message. 4. The gNB configures measurement gaps for each neighbor or extends the measurement gaps based on UE feedback. 5. The UE calculates the RTD for the neighbors after a preconfigured periodicity "Delay report periodicity" indicated by the gNB, and reports the RTD to the serving cell via an RRC message if the RTD change for the neighbors is greater than "Delta RTD Act". See Figure 21. 6. When the UE reports a neighbourhood delay difference threshold smaller than "Delta RTD deAct", measurement gaps are disabled. RTD: Round Trip Delay Delta RTD: Round trip delay between the serving cell and the neighboring cell Step 1: In some embodiments of step 1, the transmission of the neighbor cell trajectories to the UE is done in MeasObjectNR RRC. MeasConfigNR RRC Initially, the gNB configures only one measurement gap. mgrp (measurement gap repetition period) is the periodicity (in ms) at which the measurement gap repeats. Periodicities of 20, 40, 80, and 160 ms are defined in NR. gapOffset is the gap offset of the gap pattern. A total of 160 offset values ​​are not applicable for all periodicities. The offset value specifies the starting subframe in the period, so its value ranges from "0" to "mgrp-1". For example, if the periodicity is 40 ms, the offset range is from "0" to "39". mgl (measurement gap length) is the length of the measurement gap in ms. Measurement gap lengths of 1.5, 3, 3.5, 4, 5.5, and 6 ms are defined in NR. mgta (measurement gap timing advance): If configured, the UE starts measurements mgta (ms) before the occurrence of the gap subframe. That is, the measurement gap starts at a time mgta (ms) advanced relative to the end of the latest subframe that occurs just before the measurement gap. The amount of timing advance may be 0.25 ms (FR2) or 0.5 ms (FR1). See Figure 22. Step 2: In some embodiments of step 2, the UE calculates the nearby transmission delay based on nearby satellite orbits reported by the UE. I. If any of the advertised neighbors are outside the SMTC window of the measurement configuration (see Figure 24) Note: The satellite transmission delay calculation mechanism is still under discussion in RAN1. Step 3: In one embodiment of step 3, UE trigger event “delay A1” proximity measurement delay delta > “threshold X” Step 4: In one embodiment of step 4, the gNB configures an additional MeasGap via RRC Reconfiguration. See Figure 25. NOTE: The gNB configures additional gap measurements only if neighbor cell SSB is not detected by changing mgl, mgrp, mgta or SMTC window size / offset. Step 5: In some embodiments of step 5, the UE configures additional gap measurements. See Figure 26. Step 6: If the UE measures a delay difference between the neighbor cell and the serving cell that is less than the "delay threshold X" In some embodiments of step 6, UE trigger event “delay A2” neighborhood measurement delay delta < “delay threshold X” Some advantages of the scheme: 1) UE location in the network is not required. 2) The SMTC measurement window does not need to extend beyond 5 ms (longer SMTC windows degrade spectral efficiency) 3) The scheme can work at any time for nearby satellite types LEO600-LEO1500-GEO. 4) Gaps are dynamically configured to increase spectral efficiency. 5) Gap configuration can be minimized because the gNB has delay information of nearby satellites. 6) Obtaining nearby satellite delay information improves RACH and HO performance. 7) Giving gNB the flexibility to choose between “gap period implementation complexity” versus “optimal resource utilization”.

[0123] Appendix: In NR, cell quality is measured by using SSBs. Each SSB has two synchronization signals and a physical broadcast channel with a longer transmission periodicity compared to the cell reference signal (CRS). The SSB periodicity can be configured in the range of 5, 10, 20, 40, 80, and 160 ms for each cell. However, the terminal does not need to measure the cell quality with the same periodicity as the SSBs, and an appropriate measurement periodicity can be configured depending on the channel conditions. This avoids unnecessary measurements and saves terminal power. A new SSB-based Radio Resource Management (RRM) Measurement Time Configuration (SMTC) window is introduced to inform the terminal of the periodicity and timing of the SSBs that the terminal must use for cell quality measurement. The SMTC window periodicity may be set in the same range as the SSBs (i.e., 5, 10, 20, 40, 80, and 160 ms), and the window duration may be set to 1, 2, 3, 4, or 5 ms depending on the number of SSBs sent for the cell being measured. Once the SMTC window is informed by the gNB, the UE detects and measures the SSB within the window and reports the measurement results to the serving base station. SS block based RRM measurement timing configuration or SMTC is the measurement window periodicity / duration / offset information for UE RRM measurements per carrier frequency. For intra-frequency connected mode measurements, up to two measurement window periodicities can be configured. For idle mode measurements, a single SMTC is configured per carrier frequency. For inter-frequency connected mode measurements, a single SMTC is configured per carrier frequency. See Figure 27. Using the same RF transceiver for measuring the quality of neighboring cells or other component carriers and for transmitting and receiving data in the serving cell allows for reduced implementation costs. Nevertheless, this means that no data can be transmitted or received in the serving cell during measurements of other cells or component carriers of different frequencies. In LTE, UE data transmission in the serving cell is stopped during the measurement gap, providing the UE with an opportunity to adjust its RF transceiver to perform measurements of the quality of neighboring cells or measurements of other component carriers of different frequencies. In NR, the concept of measurement gaps is used. However, measurements are performed on SSBs and the measurement gap configuration is improved compared to LTE. In LTE, the measurement gap length (MGL) is fixed and at least one primary / secondary synchronization signal can be observed within the gap. In LTE, primary / secondary synchronization signals are sent every 5 ms. Thus, the MGL in LTE is 6 ms, allowing 0.5 ms for RF adjustment at the beginning and end of the measurement gap. The terminal detects the synchronization signal in the MGL and identifies the cell ID and reception timing. The terminal later performs measurements on the CRS. In NR, the SMTC window duration can be set to accommodate SSB transmissions. However, a fixed MGL can result in potential degradation of serving cell throughput. As an example, if the SMTC window duration is 2 ms and the MGL is 6 ms, an interval of 4 ms is not available for data transmission and reception in the serving cell. The measurement gap pattern is characterized by MGRP and MGL. There are 24 gap pattern configurations defined in 38.133 to cover all needs for NR and E-UTRAN measurements. The measurement gap patterns are pre-sent in the table below (FIG. 28). Configuration provided by NR RRC In the following cases, the NR RRC is responsible for providing the measurement gap pattern configuration to the UE. This is done using the MeasGapConfig IE in the MeasConfig IE and is carried by the RRC Reconfiguration message. The NR RRC is responsible for: · Configure the UE for NR standalone operation (single carrier, with NR CA and NR-DC) or gapUE or gapFR1 in NE-DC configuration. Configure the UE with gapFR2 in any configuration (i.e., NR standalone operation (single carrier, with NR CA and NR-DC) or EN-DC or NE-DC). The MeasGapConfig IE specifies the measurement gap configuration and controls the setup / release of the measurement gap. Details of this IE are given below (Figure 29); *gapOffset: This can be defined as the offset of the gap pattern. There are about 160 offset values, but not all values ​​are applicable for all periodicities. The offset value specifies the starting subframe in the period, so its value ranges from "0" to "mgrp-1". For example, if the periodicity is 20 ms, the offset range is from "0" to "19". * Measurement Gap Length (mgl): This is the length of the measurement gap in ms. The measurement gap lengths may be 1.5, 3, 3.5, 4, 5.5, and 6 ms. * Measurement Gap Repetition Period (mgrp): This defines the periodicity (in ms) at which the measurement gaps recur. This can be configured as 20, 40, 80, and 160 ms. * Measurement Gap Timing Advance (Mgta): If configured, the UE starts measurements mgta (ms) before the occurrence of the gap subframe. That is, the measurement gap starts at a time mgta (ms) advanced relative to the end of the latest subframe that occurs just before the measurement gap. The amount of timing advance may be 0.25 ms (FR2) or 0.5 ms (FR1). See Figure 30. Handling Measurement Gaps (from a Medium Access Control (MAC) perspective) During a measurement gap, on the serving cell in the corresponding Frequency Range (FR) of the measurement gap, the MAC entity: Does not perform Hybrid Automatic Repeat Request (HARQ) feedback, Scheduling Request (SR), and Channel State Information (CSI) transmission ·Does not report Sounding Reference Signal (SRS) Do not transmit on the uplink (UL) shared channel (SCH) except for Msg3 No reception on the Downlink (DL) SCH The UE does not monitor the Physical Downlink Control Channel (PDCCH) except when it is waiting for Msg2 or Msg4 during the Random Access (RA) procedure. reference: 3GPP TS38.311, which is incorporated herein by reference in its entirety. 3GPP TS38.821, which is incorporated herein by reference in its entirety. 3GPP TS38.811, which is incorporated herein by reference in its entirety. 5G Wireless Performance and Management https: / / www.nttdocomo.co.jp / english / binary / pdf / corporate / technology / rd / technical_journal / bn / vol20_3 / vol20_3_009en.pdf, the entirety of which is incorporated herein by reference.

Claims

1. A method performed by a terminal, comprising: receiving satellite orbit data and synchronization signal (SS) / physical broadcast channel (PBCH) block measurement timing configuration (SMTC) from the network; adjusting the propagation delay with respect to neighboring cells; sending a delay propagation report to the network; A method for providing the above.

2. The method of claim 1 , further comprising receiving an adjusted SMTC.

3. The method of claim 1 , wherein the SMTC includes at least one of an offset, a periodicity, and a duration of a cell measurement window.

4. The method of claim 1 , wherein the orbital data includes at least one of a position of the satellite, a velocity of the satellite, and a relative cell position within the satellite.

5. The method of claim 1 , wherein the network comprises a serving cell.

6. The method of claim 5 , wherein the propagation delay comprises a delay difference representing a difference in propagation delay between the serving cell and the neighboring cell.

7. receiving satellite orbit data and synchronization signal (SS) / physical broadcast channel (PBCH) block measurement timing configuration (SMTC) from the network; adjusting the propagation delay with respect to neighboring cells; sending a delay propagation report to the network; To cause a terminal to perform an operation comprising: A non-transitory computer-readable medium containing instructions executable by said terminal.

8. The computer-readable medium of claim 7 , wherein the operations further comprise receiving an adjusted SMTC.

9. The computer-readable medium of claim 7 , wherein the SMTC comprises at least one of an offset, a periodicity, and a duration of a cell measurement window.

10. 8. The computer readable medium of claim 7, wherein the orbital data includes at least one of a position of the satellite, a velocity of the satellite, and a relative cell position within the satellite.

11. The computer-readable medium of claim 7 , wherein the network comprises a serving cell.

12. The computer-readable medium of claim 11 , wherein the propagation delay comprises a delay differential that represents a difference in propagation delay between the serving cell and the neighboring cell.

13. receiving satellite orbit data and synchronization signal (SS) / physical broadcast channel (PBCH) block measurement timing configuration (SMTC) from the network; adjusting the propagation delay with respect to neighboring cells; sending a delay propagation report to the network; A terminal comprising a controller including circuitry configured to execute the steps of:

14. The terminal of claim 13 , wherein the controller is further configured to: receive an adjusted SMTC.

15. The terminal of claim 13, wherein the SMTC includes at least one of an offset, a periodicity, and a duration of a cell measurement window.

16. 14. The terminal of claim 13, wherein the orbital data includes at least one of the positions of the satellites, the velocities of the satellites, and relative cell positions within the satellites.

17. The terminal of claim 13 , wherein the network comprises a serving cell.

18. The terminal of claim 17 , wherein the propagation delay comprises a delay difference that represents a difference in propagation delay between the serving cell and the neighbor cell.

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