Satellite signal propagation delay variation compensation

Abstract

Variations in satellite signal propagation delay can be compensated for by: transmitting satellite ephemeris data and cell measurement window specifications to the terminal; receiving an indication from the terminal that the cell measurement signal will arrive at the terminal outside the time frame defined by the cell measurement window specifications; modifying the cell measurement window specifications based on the propagation delay difference between the serving cell defining the cell measurement window specifications and the neighboring cells transmitting 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 neighboring cells; and transmitting the modified cell measurement window specifications to the terminal.

Description

Background Technology

[0001] When a terminal connects to a serving cell of a network, it is provided with a time window during which it can perform measurements on neighboring cell signals. Some neighboring cells can communicate via satellite.

[0002] Due to the movement of the satellite, the propagation delay of the signals (including measurement signals) transmitted to the terminal constantly changes. As the satellite moves, this delay may also change over time for a given terminal. With this movement, the timing of the measurement signals will also drift.

[0003] If the terminal cannot perform measurements on neighboring cells, it may be unable to report neighboring cell measurements or perform conditional handover assessments, thus affecting handover performance. Attached Figure Description

[0004] Figure 1A and Figure 1B This is a schematic diagram of a system for compensating for changes in satellite signal propagation delay according to at least one embodiment of the present invention.

[0005] Figure 2A and Figure 2B This is a diagram illustrating the relative timing between the measurement window and the measurement signal according to at least one embodiment of the present invention.

[0006] Figure 3 This is an operational procedure for detecting changes in satellite signal propagation delay according to at least one embodiment of the present invention.

[0007] Figure 4 This is an operational procedure for reporting changes in satellite signal propagation delay according to at least one embodiment of the present invention.

[0008] Figure 5 This is an operational procedure for compensating for changes in satellite signal propagation delay according to at least one embodiment of the present invention.

[0009] Figure 6 This is a diagram illustrating the relative timing between a measurement window with a modified duration and a measurement signal according to at least one embodiment of the present invention.

[0010] Figure 7 This is a diagram illustrating the relative timing between a measurement window with a modified offset and a measurement signal according to at least one embodiment of the present invention.

[0011] Figure 8 This is a diagram illustrating the relative timing between a measurement window with a modified period and a measurement signal according to at least one embodiment of the present invention.

[0012] Figure 9This is a diagram illustrating the initial configuration of the measurement window, the additional measurement window, and the relative timing between the measurement signal and the measurement signal, according to at least one embodiment of the present invention.

[0013] Figure 10 This is an operational procedure for further compensating for changes in satellite signal propagation delay according to at least one embodiment of the present invention.

[0014] Figure 11 This is another operational procedure for compensating for changes in satellite signal propagation delay according to at least one embodiment of the present invention.

[0015] Figure 12 This is a block diagram of an exemplary hardware configuration for a serving cell for satellite signal propagation delay variation compensation according to at least one embodiment of the present invention.

[0016] Figure 13 This is a block diagram of an exemplary hardware configuration for a terminal for satellite signal propagation delay variation compensation according to at least one embodiment of the present invention.

[0017] Figures 14-30 The drawing is the figure of U.S. Provisional Patent Application Serial No. 63 / 140,578, which claims priority to this application. Detailed Implementation

[0018] The following disclosure provides numerous different embodiments or examples for implementing various features of the provided subject matter. Specific examples of components, values, operations, materials, arrangements, etc., are described below to simplify this disclosure. Of course, these are merely examples and not limiting. Other components, values, operations, materials, arrangements, etc., may be contemplated. Furthermore, reference numerals and / or letters may be repeated in various examples. Such repetition is for simplicity and clarity and does not in itself establish relationships between the various embodiments and / or configurations discussed.

[0019] During handover from a serving cell to a neighboring cell, the terminal can perform measurements to properly synchronize and connect to the neighboring cell. In some embodiments, such as when the serving cell and the neighboring cell are operating at different carrier frequencies, the terminal cannot simultaneously communicate with the serving cell and synchronize and connect with the neighboring cell. Therefore, in some wireless technologies such as 5G NR, a measurement gap is provided by the network to allow the terminal to perform appropriate measurements with the neighboring cell in order to synchronize and connect to the neighboring cell. In some embodiments such as 5G NR, the terminal performs measurements on the synchronization signal block (SSB) of the neighboring cell during the measurement gap. In some embodiments, the network uses the SSB-based Radio Resource Management (RRM) Measurement Time Configuration (SMTC) protocol to provide timing for the neighboring cell's SSB.

[0020] When a terminal connects to a serving cell, the network provides the terminal with an SMTC specification, which defines the window of time during which the terminal can perform measurements on the SSBs of neighboring cells. The SMTC specification includes the window period, offset, and duration, and is based on the timing of the serving cell (also known as the primary cell (PCell)). The SMTC window period (also known as the Measurement Interval Repetition Period (MGRP)) can be 5, 10, 20, 40, 80, or 160 ms, while the SMTC window duration can be 1, 2, 3, 4, or 5 ms. The serving cell does not schedule communication with the terminal during the measurement interval. The network ensures that SSBs from neighboring cells are transmitted during the measurement interval, enabling the terminal to measure the strength and quality of neighboring cell SSBs. In some embodiments, the terminal will perform neighboring cell measurements at standardized intervals.

[0021] In a Low Earth Orbit (LEO) Non-Terrestrial Network (NTN) scenario, the propagation delay of neighboring satellite cell SSBs to the terminal constantly changes due to the movement of satellite cells. This delay varies based on the terminal's relative position on the ground. As satellite cells move, the delay of neighboring satellite cells to the terminal also changes over time. With this movement, the timing of neighboring satellite cell SSBs measured by the terminal will also drift. The terminal also moves, but the impact of the terminal's movement on the ground is negligible compared to the satellite's velocity.

[0022] In NTN scenarios, terminals experience varying propagation delays between serving and neighboring satellite cells. In some cases, the SMTC window configuration and SSB reception time differ for different satellite cells, such as between cells of satellites located at different points in the network. Reducing the measurement gap size allows more time to be dedicated to communication with the serving cell, rather than measuring neighboring cells. However, due to the small measurement gap size, the risk of the terminal missing SSBs of neighboring satellite cells used for Radio Resource Management (RRM) measurements increases for inter-frequency or even intra-frequency neighboring cells. The SMTC window duration is at most 5ms, therefore a statically configured SMTC window cannot handle large variations in propagation delay depending on where the neighboring satellite cell's SSB initially lies within the SMTC window. Since the terminal does not need to monitor SSBs outside the configured SMTC window, measuring neighboring satellite cells is challenging under the current SMTC configuration options.

[0023] There are variations in propagation delays during handovers between LEO satellites operating at the same altitude, and these variations are more pronounced between LEO satellites operating at different altitudes, and even more pronounced between LEO satellites and geostationary orbit (GEO) satellites. Furthermore, due to location differences, each terminal will experience different variations in propagation delays between the same satellites within the same time period. As mentioned below in R2-2010795, for NTN systems, the SMTC window should be enhanced because the SMTC window needs to follow the delay variations between the serving cell / satellite and neighboring cells / satellites.

[0024] "Under normal circumstances in a TN system, SSB bursts generated by neighboring cells are always detectable within the corresponding SMTC window configured via the serving cell. The UE does not need to measure SSB bursts outside the corresponding configured SMTC window. However, for an NTN system, based on analysis, SSB bursts generated by neighboring cells may be outside the corresponding SMTC window configured via the serving satellite. If the UE is able to obtain the propagation delay difference between the serving satellite and neighboring satellites, then even if the SSB burst is outside the corresponding configured SMTC window, the UE can still know when to detect the actual SSB burst generated by the neighboring cell. If RAN2 does not wish to make any enhancements to the SMTC configuration of the NTN, it should allow the UE to search for SSB bursts generated by neighboring cells, even outside the corresponding configured SMTC window."

[0025] The SMTC window established by the serving cell for SSB measurement should attempt to account for all possible SSB delays of all connected terminals.

[0026] Figure 1A and Figure 1B This is a schematic diagram of a system for compensating for changes in satellite signal propagation delay according to at least one embodiment of the present invention. Figure 1A The system at an earlier time is shown, while Figure 1B The system at a later time is shown.

[0027] exist Figure 1A and Figure 1BIn this scenario, satellite 120A, traveling in LEO (Left Orbit), is currently providing communication to NTN gateway 110A (the serving cell of terminal 100), while satellite 120B, traveling in LEO at a higher altitude than satellite 120A, is providing communication to NTN gateway 110B (a potential target neighboring cell). In this configuration, satellite 120A moves away from terminal 100 along trajectory 122A, while satellite 120B, on a different trajectory 122B, moves towards terminal 100. The propagation delay between satellite 120A and terminal 100 is specified as dSAT1-UE(t), i.e., a function of time t, while the delay between satellite 120B and terminal 100 is specified as dSAT2-UE(t). In some embodiments, satellites 120A and 120B do not support the NR protocol and instead simply relay signals from terrestrial gateways NTN gateways 110A and 110B, respectively. Therefore, in some cases, these satellites are referred to as "transparent." 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 includes the serving cell of the cellular network, while satellite 120B includes a neighboring cell of the cellular network; both fully support the NR protocol and therefore act as satellite cells. Satellite 120A is connected to and moves toward NTN gateway 110A, while satellite 120B is connected to and moves toward NTN gateway 110B. Figure 1A The relative position of the satellite at the first time t1 is shown, while Figure 1B The relative position of the satellite at the second time t2 is shown. Figure 1B It shows that at time t2, the position of satellite 120A has changed by a distance of 124A, and the position of satellite B has changed by a distance of 124B. The corresponding propagation delays between the satellites and the gateway are dSAT1-GW1(t) and dSAT1-GW2(t).

[0028] Due to the movement of the satellites, the propagation delay varies over time. Table 1 provides example figures from one embodiment, where satellite 120A travels at an altitude of 600 km and satellite 120B travels at an altitude of 1500 km, based on the estimated elevation angle between the satellite cell and the land object, and both satellites 120A and 120B are transparent.

[0029] [Table 1]

[0030]

[0031] Table 1 – Variation in propagation delay for terminal gateway communication via transparent satellite

[0032] The timing of terminal 100 is based on the serving cell, NTN gateway 110A, which is in Figure 1A and 1B Communication is conducted via satellite 120A. Therefore, terminal 100 will experience SSB drift from satellite 120B.

[0033] Based on the geometry shown in Figure 1 and Table 1, the total propagation delay between NTN gateway 110A and terminal 100 changes from approximately 5.1 ms to 6.1 ms, while the total propagation delay between NTN gateway 110B and terminal 100 decreases from approximately 13.4 ms to 10.6 ms. Therefore, the difference in total propagation delay between the connection via satellite 120A and the connection via satellite 120B, as observed by terminal 100, changes from 8.3 ms at t1 to 5.5 ms at t2. Therefore, according to the configuration established by NTN gateway 110A at t1, the SSB from NTN gateway 110B, coordinated to arrive within the SMTC window, will actually fall outside the SMTC window at t2.

[0034] Figure 2A and Figure 2B This is a diagram illustrating the relative timing between the measurement window and the measurement signal according to at least one embodiment of the present invention. Figure 2A It shows things like Figure 1A The relative timing at earlier times such as t1 in the text, while Figure 1B It shows things like Figure 1B The relative timing at later times such as t2 in the text.

[0035] Figure 2A The expected timeline 236 is shown when the measurement window and measurement signal are coordinated. As coordinated, measurement window 230A opens at time 232A, and measurement signal 237A, transmitted at time 238A, is received before measurement window 230A closes. Similarly, measurement window 230B opens at time 232B, and measurement signal 237B, transmitted at time 238B, is received before measurement window 230B closes.

[0036] Figure 2B It shows that due to Figure 1A and Figure 1BThe timeline 236 is caused by changes in propagation delay due to the satellite ephemeris table shown. Because the total propagation delay between NTN gateway 110A, serving cell, and terminal 100 changes from approximately 5.1 ms to 6.1 ms, measurement window 230A begins at time 232A after a 1 ms delay 233A. Because the total propagation delay between NTN gateway 110B, neighboring cell, and terminal 100 changes from approximately 13.4 ms to 10.6 ms, measurement signal 237A begins at time 238A with a 2.8 ms advance 239A. This causes measurement signal 237A to arrive at terminal 100 outside of measurement window 230A. Unless compensated, terminal 100 will not receive measurement signal 237A. Measurement window 230B and measurement signal 237B are affected in substantially the same way.

[0037] Figure 3 This is an operational procedure for detecting changes in satellite signal propagation delay according to at least one embodiment of the present invention. In some embodiments, the operational procedure provides a method for detecting changes in satellite signal propagation delay by a serving cell communicating with a terminal. In some embodiments, the operation is performed by a detection section of the serving cell communicating with the terminal or its corresponding named sub-section.

[0038] In S340, the detection area or its sub-area transmits satellite ephemeris data and cell measurement window specifications to the terminals. When more than one terminal is connected to the serving cell, the detection area transmits ephemeris data and cell measurement window specifications to all connected terminals. Figure 1A and Figure 1B In the scenario shown, more than one of the serving cell and neighboring cells is communicating with the terminal via satellite, and ephemeris data for each satellite is transmitted to the terminal.

[0039] In some embodiments, the cell measurement window specification includes a period, 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 in which neighboring cells transmit cell measurement signals. In these embodiments, the cell measurement window specification includes a period 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 because the measurement window is a time frame within the gap, which is filled with non-transmission time on either side. Also in SMTC protocol embodiments, the offset gapOffset ranges from 0 to 1 less than the period mgrp. For example, if mgrp is 80, then the range of gapOffset is 0 to 79. In SMTC protocol and other embodiments, the cell measurement window specification is transmitted as part of the MeasConfig via Radio Resource Control (RRC) signaling.

[0040] In some embodiments, ephemeris data represents satellite position, satellite velocity, and reference position. In some embodiments where the satellite is transparent, the ephemeris data further represents the gateway position. In some embodiments, the ephemeris data is also transmitted via RRC signaling. In these and some other embodiments, the range and resolution of each value in the ephemeris data may affect spectral efficiency and accuracy. In some embodiments, the satellite position is three coordinate values ​​with a range of ±50,000 km and a resolution of 0.4 m, utilizing 84 bits; the satellite velocity is three scalar values ​​with a range of ±8 km / s and a resolution of 0.015 km / s, utilizing 60 bits; and the reference position is three coordinate values ​​with a range of ±6,500 km and a resolution of 0.4 m, utilizing 75 bits. In the SMTC protocol and other embodiments, the ephemeris data is transmitted via Radio Resource Control (RRC) signaling as part of the MeasObjectNR.

[0041] In some embodiments, the detection zone further transmits one or more reporting conditions. In some embodiments, the reporting conditions include a delayed reporting period, a delay difference threshold, and a gap sequence value. In some embodiments, the delayed reporting period is much larger than the measurement window period, such as exceeding 1000 ms. In some embodiments, the terminal can use the delay difference threshold to determine whether to transmit a report or whether to include an indication in the report. In some embodiments, two delay difference thresholds are used such that once the delay difference increases beyond the higher threshold within 1 to 1000 ms, an alarm is triggered, and the alarm remains active until the delay difference decreases beyond the lower threshold within 1 to 1000 ms. Having a higher activation threshold and a lower deactivation threshold results in fewer false alarms and missed alarms. In some embodiments, the gap sequence determines which neighboring cells will transmit during the same gap period or during which gap within the measurement window. In some embodiments where the terminal performs further analysis, the reporting condition is that the terminal determines that the measurement signal will arrive at the terminal outside the time frame defined by the cell measurement window specification. In some embodiments, the detection zone instructs the terminal to send a report under any circumstances. In the SMTC protocol and other embodiments, the reporting conditions are transmitted via Radio Resource Control (RRC) signaling as part of the MeasObjectNR.

[0042] In S342, the detection area or its sub-area receives an indication from the terminal that the cell measurement signal will arrive at the terminal outside the time frame defined by the cell measurement window specification. In some embodiments, this indication is received via RRC signaling. In some embodiments, the indication includes information representing the offset between the measurement window and the measurement signal perceived by the terminal transmitting the indication, information allowing the serving cell to determine the offset between the measurement window and the measurement signal perceived by the terminal transmitting the indication, or any other information that the serving cell can use to determine appropriate compensation. In some embodiments, the indication includes confirmation that the cell measurement signal will arrive at the terminal within the time frame defined by the cell measurement window specification. In some embodiments, the indication includes a delay difference representing the propagation delay difference between the serving cell and neighboring cells of the cellular network. If more than one of the neighboring cells is communicating with the terminal via satellite, more than one indication can be received from the terminal. If more than one terminal is connected to the serving cell, the detection area can receive one or more indications from each connected terminal. In some embodiments, the indication includes the geographical location of the terminal, and in some of these embodiments, no other information is available.

[0043] In S344, the detection area or its sub-area determines whether all indications have been received in response to the transmission of measurement window specifications and ephemeris data. In some embodiments, the detection area refers to a time limit for the terminal to transmit indications, or other criteria used to determine that all indications to be considered have been received. In some embodiments, the terminal sends an indication regardless of whether the cell measurement signal will arrive at the terminal within the time frame defined by the cell measurement window specification, and the detection area waits until indications are received from each connected terminal. If the detection area determines that all indications have been received according to the criteria, the operation proceeds to S346 to continue the detection process. If the detection area determines that the criteria have not yet been met, the operation returns to S342 to receive additional indications.

[0044] At S346, the detection area or its sub-area determines the relative timing between the measurement window and measurement signal of any neighboring cell perceived by the connected terminal. In some embodiments, the connected terminal will directly provide the relative timing in the indication received at S342. In some embodiments, the detection area determines whether there is overlap based on other information provided by the terminal in the indication received at S342. In some embodiments where the indication received at S342 includes the geographical location of the terminal, the detection area performs all the calculations required to make a determination for each terminal for each neighboring cell. If the detection area determines, based on all received indications, that all measurement signals will be received within the measurement window as perceived by the terminal, the operation process ends without further compensation. If the detection area determines that the measurement signal will be received outside the measurement window of the connected terminal, the operation process proceeds to S360 to perform compensation. In some embodiments, the decision at S346 is not based on whether a single measurement signal will arrive at a single terminal outside the measurement window, but on the number of thresholds for the terminal, neighboring stations, a certain weighting factor criterion, etc.

[0045] At S360, the compensation area for the serving cell will compensate for measurement signals arriving at the terminal outside the measurement window defined by the measurement window specification sent at S340. In some embodiments, the compensation area or its sub-area modifies the cell measurement window specification such that cell measurement signals transmitted from the satellite will arrive at the terminal within the time frame defined by the cell measurement window specification. Some embodiments of the compensation operation at S360 are related to... Figure 5 To describe in more detail.

[0046] Figure 4 This is an operational procedure for reporting changes in satellite signal propagation delay according to at least one embodiment of the present invention. In some embodiments, this operational procedure provides a method for a terminal connected to a serving cell to report changes in satellite signal propagation delay. In some embodiments, this operation is performed by a reporting area of ​​the terminal or its corresponding named sub-area.

[0047] In S450, the reporting area or its sub-area receives satellite ephemeris data and cell measurement window specifications from the serving cell of the cellular network. The satellite ephemeris data and cell measurement window specifications are essentially similar to those regarding... Figure 3 The ones described in S340. In some embodiments, the reporting area further receives reporting conditions (such as regarding...). Figure 3 (as described in S340) or instructions to send a report in any case.

[0048] In S452, the reporting area or its sub-area determines the propagation delay of each neighboring cell. In some embodiments, the reporting area determines the propagation delay difference between the serving cell of the cellular network and neighboring cells based on ephemeris data and the geographic location of the terminal. In some embodiments, the determining area obtains the geographic location from the Global Positioning System (GPS) chip within the terminal, direct user input, or otherwise, without using the cellular network. In this way, the reporting area makes the determination without providing the cellular network with the terminal's geographic location or without allowing the cellular network to obtain the terminal's geographic location. In some embodiments, the reporting area does not make any other determinations besides the propagation delay difference (such as in response to reporting conditions based on the propagation delay difference). In some embodiments, the reporting area also reports propagation delay variations because the propagation delay may differ when the measured signal arrives at the terminal. In some embodiments, the serving cell is a non-terrestrial gateway communicating with the terminal via satellite. In some of these embodiments, the reporting area further determines the propagation delay difference based on the geographic location of the non-terrestrial gateway.

[0049] In some embodiments, the reporting region uses propagation delay to further determine whether the cell measurement signal will arrive outside the time frame defined by the cell measurement window specification, such as in response to a reporting condition based on such a determination. In some cases, the reporting region determines that the cell measurement signal will arrive outside the time frame defined by the cell measurement window specification.

[0050] In S454, the reporting area or its sub-area determines whether the reporting conditions have been met. In some embodiments, the reporting area refers to the reporting conditions or reporting instructions received from the serving cell, as well as the cell measurement window specification and ephemeris data. In some embodiments, the reporting area refers to internal reporting conditions. In some embodiments where the reporting condition is a delay difference threshold, for each neighboring cell, the reporting area determines whether the propagation delay difference between the neighboring cell and the serving cell exceeds the delay difference threshold. If the reporting area determines that the reporting conditions have been met, the operation proceeds to S456 to transmit the report. If the reporting area determines that the reporting conditions have not been met, the operation ends without transmitting the report.

[0051] In S456, the reporting area or its sub-area transmits a report to the serving cell. In some embodiments, the report is transmitted via RRC signaling. In some embodiments, the reporting area transmits in the report an indication to the serving cell that the cell measurement signal will be received outside the window defined by the cell measurement window specification. In some embodiments, the report includes an indication that the propagation delay difference between the neighboring cell and the serving cell exceeds a delay difference threshold. In some embodiments, the report indicates that reporting conditions have not yet been met, such as when the serving cell instructs the terminal to send a report under any circumstances.

[0052] Figure 5 This is an operational procedure for compensating for changes in satellite signal propagation delay according to at least one embodiment of the present invention. In some embodiments, this operational procedure provides a method for compensating for changes in satellite signal propagation delay by a serving cell. In some embodiments, this operation is performed by a compensation area of ​​the serving cell or its corresponding named sub-area.

[0053] In S562, the compensation area or its sub-area modifies the cell measurement window specification. In some embodiments, the compensation area modifies at least one of the period, duration, and offset. In some embodiments, the compensation area specifies additional measurement window specifications, such as an additional measurement window having a period, duration, and offset. In some embodiments, the compensation area determines modifications that will cause at least one measurement signal from all neighboring cells to arrive at all connected terminals within a time frame defined by the measurement window specification. In some embodiments, the compensation area determines modifications that will cause at least one measurement signal from a majority of neighboring cells to arrive at a majority of connected terminals within a time frame defined by the measurement window specification. In some embodiments, the compensation area determines separate modifications for each neighboring cell, each communication channel, or each frequency band.

[0054] In S564, the compensation region or its sub-region determines the spectral efficiency of the cell measurement window specification modified at S562. In some embodiments, 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 frequencies different from the serving cell, this is directly related to the amount of time spent establishing and maintaining network communications (such as waiting for the reception of measurement signals). In some embodiments, the compensation region determines a separate spectral efficiency for each neighboring cell, each communication channel, or each frequency band.

[0055] In S566, the compensation region or its sub-region determines whether the spectral efficiency is acceptable. In some embodiments, the compensation region determines whether the spectral efficiency of the cell measurement window specification modified at S564 is acceptable by comparing the spectral efficiency with a threshold spectral efficiency value. If the compensation region determines that the spectral efficiency of the cell measurement window specification modified at S564 is acceptable, the operation proceeds to the transmission of the modified measurement window specification at S568. If the compensation region determines that the spectral efficiency of the cell measurement window specification modified at S564 is unacceptable, the operation proceeds to further modification of the measurement window specification at S562.

[0056] As S562, S564, and S566 iterate, different modifications are tried until an acceptable spectral efficiency is achieved. In some embodiments where the spectral efficiency is compared to a threshold spectral efficiency value, modifying the cell measurement window specification involves determining that the spectral efficiency of the modified cell measurement window specification is higher than the threshold spectral efficiency value. In some embodiments, an algorithm or formula is used to determine the modification with the maximum spectral efficiency. In some embodiments, an algorithm or formula is used to determine the modification of the cell measurement window specification that balances spectral efficiency with the reception of the measurement signal. For example, a modification that causes at least one measurement signal from all neighboring cells to reach all connected terminals significantly reduces spectral efficiency, especially in the case of many connected terminals.

[0057] In S568, the compensation area or its sub-area transmits the modified cell measurement window specification from S562 to the connected terminal. In some embodiments, the modified cell measurement window specification is transmitted via RRC signaling. In some embodiments, the modified cell measurement window specification is substantially similar to that in S562. Figure 3 Those transmitted at S340, but without ephemeris data and reporting conditions. In some embodiments, the modified cell measurement window specification includes individual modifications for each neighboring cell, each communication channel, or each frequency band.

[0058] Figure 6 This is a graph illustrating the relative timing between a measurement window with a modified duration and a measurement signal according to at least one embodiment of the present invention. Timeline 636 includes later times (such as...) Figure 1B The relative timing of t2 in the text. Similar to the timing of t2 in the text. Figure 2BAs described, because the total propagation delay between NTN gateway 110A, the serving cell, and terminal 100 changes from approximately 5.1 ms to 6.1 ms, the measurement window 630A begins at time 632A after a 1 ms delay 633A. Because the total propagation delay between NTN gateway 110B, the neighboring cell, and terminal 100 changes from approximately 13.4 ms to 10.6 ms, the measurement signal 637A begins at time 638A with a 2.8 ms advance 639A. However, instead of the measurement signal 637A arriving at terminal 100 outside of the measurement window 630A, the cell measurement window specification is modified by the serving cell to have a longer duration. Due to this modification, the measurement window 630A still begins at time 632A, but remains open long enough to include time 638B when the measurement signal 637B arrives at terminal 100.

[0059] In some embodiments, from the terminal's perspective, the measurement signal is advanced and the measurement window is delayed. The increased duration of the measurement window causes subsequent measurement signals to fall within the measurement window. In this case, unless the combined effect of the advanced measurement signal and the delayed measurement window exceeds half the cycle, the increased duration used to capture subsequent measurement signals will reduce spectral efficiency to below 50%. In other words, the terminal will consume more than half of the connection time or bandwidth just to maintain network connectivity. In many embodiments, spectral efficiency less than 50% is unlikely to be acceptable, and therefore, modifying the cell measurement window specification to increase the duration has a greater probability of producing acceptable spectral efficiency in other cases. For example, in some embodiments where the measurement signal is delayed and the measurement window is advanced from the terminal's perspective, modifying the cell measurement window specification to increase the duration has a greater probability of producing acceptable spectral efficiency.

[0060] Figure 7 This is a graph illustrating the relative timing between a measurement window and a measurement signal with a modified offset, according to at least one embodiment of the present invention. Timeline 736 includes later times (such as...) Figure 1B The relative timing of t2 in the text. Similar to the timing of t2 in the text. Figure 2BAs described, because the total propagation delay between NTN gateway 110B, neighboring cells, and terminal 100 changes from approximately 13.4 ms to 10.6 ms, measurement signal 737A begins at time 738A with a 2.8 ms advance 739A. The total propagation delay between NTN gateway 110A, serving cell, and terminal 100 changes from approximately 5.1 ms to 6.1 ms. However, offset 731A has been introduced into the cell measurement window specification, as modified. As a result, when measurement signal 737B arrives at terminal 100, measurement window 730A begins after time 732A with an offset 731A, which makes measurement window 730A include time 738B.

[0061] In some embodiments, from the terminal's perspective, the measurement signal is advanced and the measurement window is delayed. The introduction of the measurement window offset (i.e., an effective increase in offset from zero to a positive value) causes subsequent measurement signals to fall within the measurement window. Because the duration and period of the measurement window remain unchanged, and no other windows are introduced, the spectral efficiency also remains unchanged. In other words, compared to before the offset was introduced, the terminal will not consume more connection time or bandwidth solely for maintaining the network connection. Unchanged spectral efficiency after modification of the cell measurement window specification is more likely to be acceptable than reduced spectral efficiency. However, in some embodiments where many terminals connect to the serving cell, where many neighboring cells communicate via satellite, the relative timing between the measurement signal and the measurement window will be advanced and delayed by different amounts in different directions from the perspective of terminals with different connections. Therefore, in embodiments with many terminals, many satellites, or both, modifications to the cell measurement window specification used to introduce or increase the offset will have a lower probability of significantly increasing the number of neighboring cells transmitting at least one measurement signal to a connected terminal.

[0062] Figure 8 This is a diagram illustrating the relative timing between a measurement window with a modified period and a measurement signal according to at least one embodiment of the present invention. Timeline 836 includes later times (such as...) Figure 1B The relative timing of t2 in the text. Similar to the timing of t2 in the text. Figure 2BAs described, because the total propagation delay between NTN gateway 110A, the serving cell, and terminal 100 changes from approximately 5.1 ms to 6.1 ms, measurement window 830A begins at time 832A after a 1 ms delay 833A. Because the total propagation delay between NTN gateway 110B, the neighboring cell, and terminal 100 changes from approximately 13.4 ms to 10.6 ms, measurement signal 837A begins at time 838A with a 2.8 ms advance 839A. However, instead of measurement signal 837 arriving at terminal 100 outside any measurement window, the cell measurement window specification is modified by the serving cell to have a shorter period. Due to this modification, measurement window 830A still begins at time 832A and ends before measurement signal 837B arrives at terminal 100, but the reduced period causes another measurement window 834B to open when measurement signal 837B arrives at terminal 100.

[0063] In some embodiments, from the terminal's perspective, the measurement signal is advanced and the measurement window is delayed. The reduction in the measurement window period (i.e., an effective increase in the rate of the measurement window relative to time) leads to decreased spectral efficiency because connected terminals will consume more time waiting for the measurement signal. However, in some embodiments where many terminals connect to a serving cell, where many neighboring cells communicate via satellite, modifying the cell measurement window specification to double the rate of the measurement window will have a greater probability of significantly increasing the number of neighboring cells transmitting at least one measurement signal to the connected terminal, compared to modifying the amount of time consumed by connected terminals waiting for the measurement signal without increasing the amount of time.

[0064] Figure 9 This is a diagram illustrating the initial configuration of the measurement window, additional measurement windows, and relative timing with the measurement signal according to at least one embodiment of the present invention. Timeline 936 includes later times (such as...) Figure 1B The relative timing of t2 in the text. Similar to the timing of t2 in the text. Figure 2BAs described, because the total propagation delay between NTN gateway 110A, the serving cell, and terminal 100 changes from approximately 5.1 ms to 6.1 ms, measurement window 930A begins at time 932A after a 1 ms delay 933A. Because the total propagation delay between NTN gateway 110B, neighboring cells, and terminal 100 changes from approximately 13.4 ms to 10.6 ms, measurement signal 937A begins at time 938A with a 2.8 ms advance 939A. However, instead of measurement signal 937A arriving at terminal 100 outside any measurement window, the cell measurement window specification is modified by the serving cell to have an additional measurement window specification. In some embodiments, in addition to the period, duration, and offset of the original window measurement specification, the additional window measurement specification also includes a period, duration, and offset, but with different values. Due to this modification, measurement window 930A still begins at time 932A and ends before measurement signal 937B arrives at terminal 100. However, when measurement signal 937B arrives at terminal 100, the additional window measurement specification causes another measurement window 935 to open.

[0065] In some embodiments, from the terminal's perspective, the measurement signal is advanced and the measurement window is delayed. The additional window measurement specification (which effectively increases the measurement window) leads to reduced spectral efficiency because connected terminals will consume more time waiting for the measurement signal. However, in some embodiments where many terminals connect to a serving cell, where many neighboring cells communicate via satellite, modifying the cell measurement window specification to add a measurement window will have a greater probability of significantly increasing the number of neighboring cells transmitting at least one measurement signal to the connected terminal, compared to modifying the amount of time consumed by connected terminals waiting for the measurement signal without increasing the amount of time.

[0066] Figure 10 This is an operational procedure according to at least one embodiment of the present invention for further compensating for changes in satellite signal propagation delay. In some embodiments, the operational procedure provides a method for a terminal connected to the serving cell to compensate for changes in satellite signal propagation delay. In some embodiments, the operation is performed by a compensation area of ​​the terminal or its corresponding named sub-area.

[0067] In S1070, the compensation area or its sub-area receives the modified window measurement specification from the serving cell. In some embodiments, the modified window measurement specification is received via RRC signaling. In some embodiments, the modified cell measurement window specification is as follows: Figure 5 It was modified as described in S562.

[0068] In S1072, the compensation area or its sub-area determines whether the measurement signal from any neighboring cell will arrive outside the measurement window defined by the modified cell measurement window specification. Because modifying the cell measurement window specification to ensure that at least one measurement signal from all neighboring cells arrives at all connected terminals in some cases results in unacceptable spectral efficiency, some connected terminals will determine that the modified cell measurement window specification still results in the measurement signal from one or more neighboring cells arriving outside the measurement window. If the compensation area determines that the measurement signal from one or more neighboring cells will arrive outside the measurement window, the operation proceeds to individual measurement window configuration in S1074. If the compensation area determines that at least one measurement signal from all neighboring cells will arrive within the measurement window, the operation ends without individual measurement configuration.

[0069] In S1074, the compensation area or its sub-area is configured with an individual measurement window. In some embodiments, the compensation area is configured with an individual measurement window specification that defines one or more time frames within which only individual terminals wait for the arrival of a measurement signal. During the time frame defined by the individual measurement window specification, the service will not communicate with the terminal but will continue to communicate with other terminals. In this way, the reduction in spectral efficiency of the individual measurement window specification for the cell and other terminals is much smaller compared to terminals configured with an individual measurement window specification. In some embodiments where the measurement signal is advanced and the measurement window is delayed from the terminal's perspective, the compensation area configuration is similar to... Figure 9 The measurement window 935 corresponds to an individual measurement window. In some embodiments, the individual measurement window specification includes a period, a duration, and an offset, and it can be configured to receive multiple measurement signals, each from a different neighboring cell. In some embodiments, the individual measurement window specification only includes a start time and a duration, resulting in a single individual measurement window. Compared to embodiments where the individual measurement window specification results in multiple individual measurement windows, a single individual measurement window has a greater probability of leading to greater spectral efficiency, but may allow for receiving fewer measurement signals.

[0070] In S1076, the compensation area or its sub-area transmits a report on the individual measurement window specification to the serving cell. In some embodiments, the individual measurement window specification is transmitted via RCC signaling.

[0071] In S1078, the compensation area or its sub-area receives an acknowledgment from the serving cell. In some embodiments, the acknowledgment 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 the terminal with a measurement gap consistent with any time frame defined by the individual measurement window specification. In some embodiments, this acknowledgment is received via RCC signaling.

[0072] 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, causing the serving cell to utilize more computational resources. In some of these embodiments, the terminal sends more detailed information to the serving cell about the measurement window and the relative timing of the measurement signal, such as in similar... Figure 4 During the transmission of the propagation delay report in operation S456. In some of these embodiments, the serving cell transmits an individual cell measurement window specification to each terminal during the transmission of the modified cell measurement window specification, similar to... Figure 5 Operation S568.

[0073] Figure 11 This is another operational procedure for compensating for changes in satellite signal propagation delay according to at least one embodiment of the present invention. In some embodiments, this operational procedure provides a method for compensating for changes in satellite signal propagation delay by a terminal connected to the serving cell. In this embodiment, the operation is performed by a system including serving cell 1110 and terminal 1100 connected to serving cell 1110. In some embodiments, the transmission between serving cell 1110 and terminal 1100 is performed via RRC signaling.

[0074] Serving cell 1110 transmits measurement window specifications and ephemeris data 1140 to terminal 1100. In some embodiments, serving cell 1110 also transmits reporting conditions. Terminal 1100 receives the window specifications and ephemeris data 1140 and determines the delay propagation of each cell communicating with terminal 1100 via satellite. In response to determining a significant difference in delay propagation between serving cell 1110 and any neighboring cells, or in response to the determination that other reporting conditions specified by the serving cell are met, terminal 1100 transmits 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 relative timing of the measurement window and the measurement signal from the perspective of terminal 1100. Serving cell 1110 receives the delay propagation report 1156 and modifies the cell measurement window specifications in response to any indication in the delay propagation report 1156 that no measurement signal from one or more neighboring cells will arrive at terminal 1100 during any time frame defined by the cell measurement window specifications. In some embodiments, serving cell 1110 attempts to modify the cell measurement window specification such that, from the perspective of terminal 1100, at least one measurement signal from all neighboring cells will arrive within the measurement window, but no modification can achieve this with acceptable spectral efficiency. Serving cell 1110 transmits a modified cell measurement window specification 1168 to terminal 1100, which, from the perspective of terminal 1100, does not cause measurement signals from all neighboring cells to arrive within the measurement window. In response to receiving the modified cell measurement window specification 1168, terminal 1100 configures an individual cell measurement window specification 1176 to define a measurement window for receiving at least one measurement signal from any neighboring cell, from which the measurement signal will not arrive within any time frame defined by the modified cell measurement window specification 1168. Terminal 1100 transmits the individual cell measurement window specification 1176 to serving cell 1110. Serving cell 1110 responds by transmitting a consistent measurement gap 1169, which confirms that serving cell 1110 will provide a measurement gap consistent with any time frame defined by individual cell measurement window specification 1176.

[0075] In some embodiments of this system, serving cell 1110 does not transmit ephemeris data, collect propagation delay reports, or receive individual cell measurement window specifications. Instead, in these embodiments, each connected terminal (such as terminal 1100) transmits its geographic location to serving cell 1110. In some of these embodiments, serving cell 1110 makes all determinations based on this information, including determining whether the cell measurement window specification needs modification, determining modifications to the cell measurement window specification, and determining the individual cell measurement window specification. In such embodiments, serving cell 1110 (rather than connected terminals) utilizes more computing resources, meaning it is more energy-efficient for connected terminals. However, in some embodiments where connected terminals perform more determinations, energy consumption is more balanced compared to some embodiments where serving cell 1110 performs all determinations. Furthermore, in some embodiments where terminal 1100 is in a geographic area where network collection of individual geographic locations is prohibited, terminal 1100 may not have the ability to transmit its geographic location to serving cell 1110. Furthermore, in some embodiments where connected terminals only send geolocations, reporting conditions that require terminal determination cannot be used, thus requiring all terminals to always send geolocations, rather than only when the delay becomes significant or exceeds a threshold.

[0076] Figure 12 This is a block diagram of an exemplary hardware configuration for a serving cell used for satellite signal propagation delay variation compensation according to at least one embodiment of the present invention. The exemplary hardware configuration includes serving cell 1210A, which communicates with terminal 1200 and neighboring cells 1210B, 1210C, 1210D, and 1210E via cellular network 1226.

[0077] 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 comprising two or more computers, or a server host directly connected to serving cell 1210A.

[0078] In some embodiments, controller 1212 is a processor or programmable circuit system that executes instructions to cause the processor or programmable circuit system to perform operations according to the instructions. In some embodiments, controller 1212 is an analog or digital programmable circuit system or any combination thereof. In some embodiments, controller 1212 comprises physically separate storage devices or circuit systems that interact via communication. In some embodiments, storage unit 1214 is a non-volatile computer-readable medium capable of storing executable and non-executable data for access by controller 1212 during instruction execution. Communication interface 1216 transmits and receives data from network 1226.

[0079] The controller 1212 includes a detection area 1280 and a compensation area 1282. The storage unit 1214 includes ephemeris data 1284, cell measurement window specifications 1286, and compensation parameters 1288.

[0080] Detection area 1280 is a circuit system or instruction of controller 1212 that detects whether any connected terminal, such as terminal 1200, will not have any measurement signals from neighboring cells, such as neighboring cells 1210B, 1210C, 1210D, and 1210E, arriving at the connected terminal during a time frame defined by the cell measurement window specification. In some embodiments, detection area 1280 utilizes information in storage unit 1214, such as ephemeris data 1284 and cell measurement window specification 1286. Detection area 1280 may include sub-areas for performing additional functions, as described in the preceding flowchart. These sub-areas can be referenced by names associated with their functions.

[0081] Compensation region 1282 is the circuitry or instructions of controller 1212 that performs compensation for variations in satellite signal propagation delay. In some embodiments, compensation region 1282 modifies the cell measurement window specification to increase the reception of neighboring cell measurement signals with acceptable spectral efficiency. When performing compensation in some embodiments, compensation region 1282 utilizes information in storage unit 1214, such as cell measurement window specification 1286 and compensation parameters 1288. Compensation region 1282 may include sub-regions for performing additional functions, as described in the preceding flowchart. These sub-regions can be referenced by names associated with their functions.

[0082] In other embodiments, the serving cell includes other devices capable of processing logical functions to perform the operations described herein or communicating directly with such other devices. In some embodiments, the controller and storage unit are not completely separate devices, but rather share a circuit system or one or more computer-readable media. In some embodiments, the storage unit may be a hard disk drive storing computer-executable instructions and data accessed by the controller, and the controller may be a combination of a central processing unit (CPU) and RAM, wherein the computer-executable instructions may be copied in whole or in part for execution by the CPU during the execution of the operations described herein.

[0083] In embodiments where a serving cell utilizes a computer to perform the operations described herein, a program installed on the computer causes the computer to function as a serving cell of the embodiments described herein or to perform operations associated with a 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.

[0084] Figure 13 This is a block diagram of an exemplary hardware configuration of a terminal for satellite signal propagation delay variation compensation according to at least one embodiment of the present invention. The exemplary hardware configuration includes a terminal 1300, which communicates with serving cell 1310A and neighboring cells 1310B, 1310C, 1310D, and 1310E via cellular network 1326.

[0085] Terminal 1300 includes a controller 1302, a storage unit 1304, and a communication interface 1306. In some embodiments, terminal 1300 is a cellular phone, smartphone, tablet computer, laptop computer, or any other device with a cellular network communication interface.

[0086] In some embodiments, controller 1302 is a processor or programmable circuit system that executes instructions to cause the processor or programmable circuit system to perform operations according to the instructions. In some embodiments, controller 1302 is an analog or digital programmable circuit system or any combination thereof. In some embodiments, controller 1302 comprises physically separate storage devices or circuit systems that interact via communication. In some embodiments, storage unit 1304 is a non-volatile computer-readable medium capable of storing executable and non-executable data for access by controller 1302 during instruction execution. Communication interface 1306 transmits and receives data from network 1326.

[0087] The controller 1302 includes a reporting area 1390 and a compensation area 1392. The storage unit 1304 includes ephemeris data 1394, cell measurement window specifications 1396, and compensation parameters 1398.

[0088] Reporting area 1390 is a circuitry or instruction of controller 1302 that reports whether measurement signals from any neighboring cells, such as 1310B, 1310C, 1310D, and 1310E, did not arrive at terminal 1300 during the time frame defined by the cell measurement window specification. In some embodiments, reporting area 1390 utilizes information in storage unit 1304, such as ephemeris data 1394 and cell measurement window specification 1396. Reporting area 1390 may include sub-areas for performing additional functions, as described in the preceding flowchart. These sub-areas can be referenced by names associated with their functions.

[0089] Compensation area 1392 is the circuitry or instructions of controller 1302 that performs compensation for satellite signal propagation delay variations. In some embodiments, compensation area 1392 configures individual cell measurement window specifications to receive measurement signals from any neighboring cells that would otherwise not be received according to the cell measurement window specifications. When performing compensation in some embodiments, compensation area 1392 utilizes information in storage unit 1304, such as cell measurement window specifications 1396 and compensation parameters 1398. Compensation area 1392 may include sub-areas for performing additional functions, as described in the preceding flowchart. These sub-areas can be referenced by names associated with their functions.

[0090] In other embodiments, the terminal includes other devices capable of processing logical functions to perform the operations described herein. In some embodiments, the controller and storage unit are not completely separate devices, but rather share a circuit system or one or more computer-readable media. In some embodiments, the storage unit may be a hard disk drive storing computer-executable instructions and data accessed by the controller, and the controller may be a combination of a central processing unit (CPU) and RAM, wherein the computer-executable instructions may be copied in whole or in part for execution by the CPU during the execution of the operations described herein.

[0091] In embodiments where a terminal utilizes a computer processor to perform the operations described herein, a program installed on the terminal causes the terminal to function as described herein or to perform the operations of the embodiments described herein. In some embodiments, such a program may be executed by a 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.

[0092] Various embodiments of the invention are described with reference to flowchart illustrations and block diagrams, where blocks may represent (1) steps of a process for performing an operation, or (2) portions of a controller responsible for performing the operation. Certain steps and portions are implemented by a dedicated circuit system, a programmable circuit system 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 circuit system includes digital and / or analog hardware circuitry and may include integrated circuits (ICs) and / or discrete circuitry. In some embodiments, the programmable circuit system includes reconfigurable hardware circuitry including logic AND, OR, XOR, NAND, NOR and other logic operations, flip-flops, registers, memory elements, such as field-programmable gate arrays (FPGAs), programmable logic arrays (PLAs), etc.

[0093] Various embodiments of the present invention include systems, methods, and / or computer program products. In some embodiments, a computer program product includes one or more computer-readable storage media having computer-readable program instructions thereon for causing a processor to perform aspects of the present invention.

[0094] In some embodiments, a computer-readable storage medium includes a tangible device capable of retaining and storing instructions for use by an instruction execution device. In some embodiments, a computer-readable storage medium includes, for example, but not limited to, electronic storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of computer-readable storage media includes: portable computer floppy disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable optical disc read-only memory (CD-ROM), digital universal disc (DVD), memory sticks, floppy disks, mechanical encoding devices (such as punched cards or raised structures in recesses) on which instructions are recorded, and any suitable combination of the foregoing. The computer-readable storage medium as used herein should not be construed as a transient signal itself, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses passing through fiber optic cables), or electrical signals transmitted through wires.

[0095] In some embodiments, the computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to a corresponding computing / processing device, or downloaded via a network (e.g., the Internet, a local area network, a wide area network, and / or a wireless network) to an external computer or external storage device. In some embodiments, the network may include copper transmission cables, optical fiber transmission, 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 forwards them to a computer-readable storage medium within the corresponding computing / processing device.

[0096] In some embodiments, the computer-readable program instructions used to perform the operations described above are assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​(such as Smalltalk, C++, etc.) and traditional procedural programming languages ​​(such as the "C" programming language or similar programming languages). In some embodiments, the computer-readable program instructions are executed 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 case, the remote computer is connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, the electronic circuit system (including, for example, a programmable logic circuit system, a field-programmable gate array (FPGA), or a programmable logic array (PLA)) utilizes the state information of the computer-readable program instructions to execute the computer-readable program instructions, thereby individualizing the electronic circuit system to perform aspects of the present invention.

[0097] While embodiments of the invention have been described, the technical scope of any claimed subject matter is not limited to the above embodiments. It will be apparent to those skilled in the art that various changes and modifications can be made to the above embodiments. It will also be clear from the scope of the claims that embodiments with such changes or modifications are included within the technical scope of the invention.

[0098] The operations, processes, steps, and stages of each procedure performed by the apparatus, system, program, and method shown in the claims, embodiments, or figures may be performed in any order, provided that the order is not indicated by "before," "before," or similar terms, and provided that the output of the preceding process is not used in the subsequent process. Even if phrases such as "first" or "next" are used in the claims, embodiments, or figures to describe the process flow, it does not necessarily mean that the processes must be performed in that order.

[0099] According to at least one embodiment of the present invention, satellite signal propagation delay variation can be compensated for by: transmitting satellite ephemeris data and cell measurement window specifications to a terminal; receiving from the terminal an indication that the cell measurement signal will arrive at the terminal outside the time frame defined by the cell measurement window specifications; modifying the cell measurement window specifications based on the propagation delay difference between the serving cell defining the cell measurement window specifications and the neighboring cells transmitting the cell measurement signals, such that the cell measurement signals 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 cells; and transmitting the modified cell measurement window specifications to the terminal.

[0100] Some embodiments include instructions in a computer program, a method executed by a processor that executes the instructions of the computer program, and a serving cell that executes the method. In some embodiments, the serving cell includes a controller that includes circuitry configured to perform the operations in the instructions.

[0101] According to at least one embodiment of the present invention, satellite signal propagation delay variation can be compensated by: receiving satellite ephemeris data and cell measurement window specifications from the serving cell of the cellular network; determining whether cell measurement signals transmitted from neighboring cells will be received outside the time frame defined by the cell measurement window specifications based on the propagation delay difference between the serving cell and neighboring cells; and transmitting to the serving cell an indication that the cell measurement signals will be received outside the window defined by the cell measurement window specifications.

[0102] Some embodiments include instructions in a computer program, a method executed by a processor that executes the instructions of the computer program, and a terminal that executes the method. In some embodiments, the terminal includes a controller that includes circuitry configured to perform the operations in the instructions.

[0103] The foregoing has outlined features of several embodiments to enable those skilled in the art to better understand various aspects of this disclosure. Those skilled in the art will understand that they can readily use this disclosure as the basis for designing or modifying other processes and structures to achieve the same purposes and / or advantages of the embodiments described herein. Those skilled in the art will also recognize that such equivalent constructions do not depart from the spirit and scope of this disclosure, and that various changes, substitutions, and modifications can be made to them herein without departing from the spirit and scope of this disclosure.

[0104] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 137,916, filed January 15, 2021, and U.S. Provisional Patent Application Serial No. 63 / 140,578, filed January 22, 2021, which are described below and are incorporated herein by reference in their entirety.

[0105] U.S. Provisional Patent Application Serial No. 63 / 137,916

[0106] 3GPP TSG-RAN WG2 Meeting #113-e

[0107] Electronic Meeting: January 25 - February 5, 2021

[0108] Agenda Item: 8.10.3.3

[0109] Source: Rakuten Mobile

[0110] Title: SMTC and Measurement Gap Configuration for NTN

[0111] This document is used for: discussion and decision-making.

[0112] 1. Introduction

[0113] The issue of UE measurement caused by the difference in propagation delay between satellites remains controversial. The following consensus was reached during the offline discussion

[106] [NTN]SMTC and the gap (second round).

[0114] consensus:

[0115] 1. Proposal 1: The SMTC and gap configuration in NTN are configured based on the timing of PCell.

[0116] 2. RAN2 understands that UEs should not be forced to detect SSB bursts outside the corresponding SMTC window in the NTN configuration, just as the principle applies in the TN.

[0117] 3. The network in the UE and NTN should also have a consistent understanding of the measurement gap to avoid any discrepancies between the UE and the network, just as in the TN.

[0118] In this paper, we present an open problem and solution for configuring SMTC windows / gap for SSB / CSI-RS measurements of neighboring cells (with different delays) when the network does not have accurate UE location information.

[0119] 2. Discussion

[0120] 2.1 Notes on existing proposals (R2-2010795)

[0121] First, we would like to present our views on the existing proposals that need to be discussed.

[0122] Proposal 2-1: RAN2 understands that the impact on SMTC configuration due to delay differences between satellites should be addressed in the NTN. FFS: Is any enhancement to the SMTC configuration required in the NTN?

[0123] As mentioned in R2-2010795 below, the SMTC window of the NTN system should be enhanced because it needs to follow the delay variations between the serving cell / satellite and neighboring cells / satellites.

[0124] "Under normal circumstances in a TN system, SSB bursts generated by neighboring cells are always detectable within the corresponding SMTC window configured via the serving cell. The UE does not need to measure SSB bursts outside the corresponding configured SMTC window. However, for an NTN system, based on analysis, SSB bursts generated by neighboring cells may be outside the corresponding SMTC window configured via the serving satellite. If the UE is able to obtain the propagation delay difference between the serving satellite and neighboring satellites, then even if the SSB burst is outside the corresponding configured SMTC window, the UE can still know when to detect the actual SSB burst generated by the neighboring cell. If RAN2 does not wish to make any enhancements to the SMTC configuration of the NTN, it should allow the UE to search for SSB bursts generated by neighboring cells, even outside the corresponding configured SMTC window."

[0125] Proposal 1: The SMTC window should be enhanced for NTN systems because it needs to follow the delay variations between the serving cell / satellite and neighboring cells / satellites.

[0126] Proposal 2-2: Before addressing any enhancements to the SMTC configuration in NTN, RAN2 can first identify scenarios and discuss the severity of the impact.

[0127] Proposal 2: The enhancement of SMTC configuration in NTN should be addressed in detail.

[0128] Proposal 4: RAN2 cannot assume that the network will always have the accurate UE location information for SMTC window configuration in NTN.

[0129] For security and privacy reasons, a country's regulatory body may prohibit network providers from obtaining the location of the user (UE), even if satellites can obtain accurate location information.

[0130] Therefore, we believe that it cannot be assumed that all networks will always have the accurate location of the UE.

[0131] Proposal 3: Agree with Proposal 4 in R2-2010795: RAN2 cannot assume that the network will always have the accurate UE location information for SMTC window configuration in NTN.

[0132] Proposal 6-1: RAN2 understands that the impact of inter-satellite delay differences on measurement gap configuration should be addressed in the NTN. FFS: Is any enhancement to the measurement gap configuration required in the NTN?

[0133] According to R2-2010795, if the measurement gap configuration enhancement proves to be required in the NTN system, the following options may be considered.

[0134] Option 1: Extend the length of the measurement gap to ensure that the length is greater than or equal to the SSB cycle.

[0135] Option 2: Reuse current signaling for measurement gap configuration (i.e., configure measurement gaps by frequency), and the timing of the configured measurement gap refers to the timing on the satellite or NTN GW. For the configured measurement gap, the UE / NW derives the UE-side measurement gap based on its location and the ephemeris of candidate satellites. Since the actual timing of the UE-side SMTC window for cells in other satellites will change from time to time based on satellite movement, the NW needs to derive the actual timing of the UE-side measurement gap based on the UE's location and the ephemeris of candidate satellites. Note: In this alternative, the measurement gap for each satellite remains unchanged.

[0136] Option 3: Configure multiple measurement gaps by frequency, and the timing of the configured measurement gaps refers to the timing of the PCell on the UE side.

[0137] Option 4: Extend the length of the measurement gap based on the maximum propagation delay difference between the serving satellite and neighboring satellites to avoid the UE missing SSB bursts of neighboring satellites.

[0138] Option 5: Apply measurement interval timing periodically to detect all possible SSBs in advance.

[0139] For option 1, measurement gap extension should not be discussed first, because measurement gap period extension will reduce spectral efficiency, since data cannot be scheduled during the measurement gap period.

[0140] We propose a method for determining the measurement gap of a UE without requiring the gNB to have UE location information. This method can be effectively used in other options, such as options 2 and 3.

[0141] assumed:

[0142] 1) Based on Proposal 6-1 Option 2:

[0143] "The measurement gap on the UE side is derived by the UE / NW based on its location and the ephemeris of candidate satellites. Since the actual timing of the SMTC window on the UE side of the cell in other satellites will change from time to time based on satellite movement, the NW needs to derive the actual timing of the measurement gap on the UE side based on the UE's location and the ephemeris of candidate satellites. Note: In this alternative, the measurement gap for each satellite remains constant."

[0144] 2) Based on the consensus in RAN1 meeting #103, it can be assumed that the UE will always obtain its location information via GNSS.

[0145] Proposal 4: Agree with the following method for determining the UE measurement gap when the gNB does not need to have UE location information.

[0146] 1.gNB needs to transmit neighboring cell ephemeris tables to the UE in RRC signaling as part of MeasObjectNR RRC.

[0147] 2. The UE can calculate the propagation delay of neighboring cells / satellites based on its location and neighboring satellite ephemeris tables.

[0148] 3. If the UE detects a significant RTD > “X” ms difference between the serving satellite and neighboring satellites, it will notify the gNB via an RRC message.

[0149] 4.gNB will then configure a measurement gap for each neighbor, or extend the measurement gap based on UE feedback.

[0150] 5. The UE needs to calculate the neighbor's RTD after the pre-configured period "Y" indicated by the gNB, and report the RTD to the serving cell via RRC message if the neighbor's RTD changes > "Z".

[0151] Proposal 6-2: Before addressing any enhancements to the measurement gap configuration in NTN, RAN2 can first identify the scenarios and discuss the severity of the impact.

[0152] The severity of the impact can be assessed in RAN2, but it should be agreed that a solution is needed to meet the proper configuration of the measurement gap / SMTC to detect SSB / CSI-RS.

[0153] Proposal 5: A solution is needed to meet the proper configuration of the measurement gap / SMTC for detecting SSB / CSI-RS.

[0154] Proposal 7: RAN2 cannot assume that the network will always have the accurate location information of the UEs configured in the measurement gap in the NTN (20 / 5).

[0155] Proposal 6: Agree with Proposal 7 in R2-2010795: RAN2 cannot assume that the network will always have the accurate location information of the UEs configured in the measurement gap in the NTN.

[0156] Proposal 8: Further discussion is needed in RAN2 before sending LS to RAN4 to clarify the measurement requirements for SMTC / gap configuration in NTN (16 / 6).

[0157] Proposal 7: Agreed with Proposal 8 in R2-2010795: Further discussion is needed in RAN2 to clarify the measurement requirements for SMTC / gap configuration in NTN before sending LS to RAN4.

[0158] U.S. Provisional Patent Application Serial No. 63 / 140,578

[0159] 1. Introduction

[0160] The measurement problems of user equipment (UE) caused by the difference in propagation delay between satellites remain controversial.

[0161] The following consensus was reached during the offline discussion

[106] [NTN] on the measurement timing configuration (SMTC) and gaps (second round) of the synchronization signal (SS) / physical broadcast channel based (PBCH).

[0162] consensus:

[0163] 1. Proposal 1: The SMTC and gap configuration in NTN are configured based on the timing of the primary cell (PCell).

[0164] 2. Radio Access Network 2 (RAN2) understands that UEs should not be forced to detect SSB bursts outside the corresponding SMTC window in the NTN, just as the principle applies in the Terrestrial Network (TN).

[0165] 3. The network in the UE and NTN should also have a consistent understanding of the measurement gap to avoid any discrepancies between the UE and the network, just as in the TN.

[0166] 4. In the Rel-17 New Radio (NR) NTN, at least a UE is supported that can derive one or more of the following based on its Global Navigation Satellite System (GNSS): its position, reference time, and frequency. Radio Access Network 1 (RAN1) 102e

[0167] background:

[0168] During a UE's handover 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 are operating at different carrier frequencies, the UE cannot simultaneously transmit / receive with the serving cell and synchronize and connect with the neighboring cell. Therefore, in some wireless technologies such as 5G NR, the 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 it. In some embodiments such as 5G NR, the UE performs measurements on the SSB of the neighboring cell during the measurement gap. In some embodiments, the network uses SMTC to provide timing for the neighboring cell's SSB.

[0169] In connected mode, the UE is provided with an SMTC by the network, which defines the time window during which the UE can perform measurements on the SSBs of neighboring cells. The SMTC includes a window period, offset, and window duration, and is based on the timing of the primary cell (PCell) (also known as the "serving cell"). The window period (measurement interval) can be configured to 5, 10, 20, 40, 80, or 160 ms, while the SMTC window duration can be configured to 1, 2, 3, 4, or 5 ms. See Figure 1 below (from this application). Figure 14 The illustration shows an SMTC / measurement gap configuration according to some embodiments.

[0170] In some embodiments, a measurement gap is configured based on UE capabilities when the UE cannot measure the SSB of neighboring cells while simultaneously monitoring the serving cell. In some embodiments, the serving cell does not schedule the UE during the measurement gap. The network ensures that SSBs from neighboring cells are transmitted during the measurement gap, allowing the UE to measure the SSB strength and quality of neighboring cells. In some embodiments, the UE needs to measure neighboring cell measurements at appropriate intervals to meet the requirements of TS 38.133. TS 38.133 is incorporated herein by reference in its entirety. Figure 2 (in this application) Figure 15 The illustration shows a more detailed view of the measurement gap / SMTC configuration according to some embodiments.

[0171] Exemplary problems solved by this disclosure:

[0172] In Low Earth Orbit (LEO) NTN scenarios, the propagation delay of neighboring cell SSBs to 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 vary based on the relative position of the UE on the ground, as illustrated below for User Equipment 1 (UE1) and User Equipment 2 (UE2). The window used for SSB measurement should consider all possible neighboring cell SSB delays, i.e., all possible delays between UE1 and UE2. As the satellite moves, the neighboring cell delay of the UE also changes over time. Figure 3 (in this application) Figure 16 In this scenario, when the satellite beam moves across the ground, the propagation delay experienced by the UE at location UE1 will change to the propagation delay experienced by the UE at location UE2. With this movement, the neighboring cell SSB timing measured by the UE will also drift. Note that the UE can also move, but the effect of UE movement is largely negligible because it is insignificant compared to the satellite velocity.

[0173] The following Figure 4 (in this application) Figure 17 The illustration shows variations in propagation delay in LEO NTN according to some embodiments. If the UE cannot perform SSB measurements of neighboring cells, it may be unable to report neighboring cell measurements or perform conditional handover assessment. This will adversely affect handover performance, causing the UE to unexpectedly disconnect. Handover is critical in LEO NTN scenarios due to satellite movement.

[0174] In NTN, the UE experiences varying propagation delays between the serving cell and neighboring cells. The SMTC configuration and SSB receive window can differ for different cells, for example... Figure 4 As shown, between cells of satellites at different locations. The UE can only configure one measurement gap, and the maximum length of the measurement gap is 6ms. Therefore, for adjacent cells between frequencies or even within a frequency range, the configured measurement gap may not work, and the UE may miss the SSBs of adjacent cells used for Radio Resource Management (RRM) measurements, such as... Figure 5 As shown (in this application) Figure 18 ).

[0175] The basic scenario is illustrated in error! Reference source not found, where SAT1 [LEO 600] is currently serving the UE's cell, while SAT2 [LEO 1500] (is a potential target neighboring cell). In the scenario under consideration, SAT1 is moving away from the UE, while SAT2 may be moving towards the UE on a different trajectory. The propagation delay between SAT1 and the UE is denoted as d. SAT1-UE(t), that is, a function of time t, while the delay between SAT2 and UE is expressed as d. SAT2-UE (t). Note that in the transparent satellite scenario, the propagation delay also depends on the relative position of the NTN gateway on Earth. In this example, SAT1 is connected to NTN-GW1 and moves towards NTN-GW1, while SAT2 is connected to NTN-GW2 and moves towards NTN-GW2. The corresponding propagation delay between the satellite and the gateway is d. SAT1-GW1 (t) and d SAT1-GW2 (t).

[0176] Due to satellite movement, propagation delay varies over time. Error! No example figures were found providing the estimated elevation angles between the UE and SAT1 / SAT2, and between NTN-GW1 and SAT1, and between NTN-GW2 and SAT2. In this example, the LEO satellite is assumed to be at an altitude of 600 km.

[0177] refer to Figure 19 .

[0178] According to the most recent RAN2 consensus listed in the introduction, the UE's timing is based on the serving cell, which is SAT1 in this example. Therefore, the UE will experience SSB drift from the neighboring cell (SAT2).

[0179] based on Figure 4 Based on the assumed scenario geometry in Table 1, the propagation delay between NTNGW1 and the UE changes from 5.1 ms to 6.1 ms, while the propagation delay between NTN-GW2 and the UE decreases from approximately 13.4 ms to 10.6 ms. Therefore, the delay difference observed by the UE between the two connections changes from 18.5 ms at T1 to 16.7 ms at T2. The maximum SMTC window duration is 5 subframes, and therefore a statically configured window may not be able to handle changes in propagation delay, depending on the initial time position of SAT2's SSB within the SMTC window.

[0180] Since RAN2 has agreed that the UE does not need to monitor SSBs outside the configured SMTC window, RAN2 faces challenges in measuring neighboring cells under the current SMTC configuration options, at least for the (semi-)static SMTC configuration.

[0181] Due to the latency difference, the gap configuration must be dynamically adjusted; the SMTC window will follow the dynamically defined gap configuration.

[0182] This problem becomes even more apparent in the case of LEO to geostationary orbit (GEO).

[0183] 38.811: Reference Figure 20 .

[0184] 2. Discussion

[0185] 2.1 Notes on existing proposals (R2-2010795)

[0186] First, the viewpoints on the existing proposals that need to be discussed are incorporated into this paper in their entirety by reference.

[0187] Proposal 2-1: RAN2 understands that the impact on SMTC configuration due to delay differences between satellites should be addressed in the NTN. FFS: Is any enhancement to the SMTC configuration required in the NTN?

[0188] As mentioned in R2-2010795 below, the SMTC window of the NTN system should be enhanced because the SMTC window needs to follow the delay variations between the serving cell / satellite and neighboring cells / satellites.

[0189] "Under normal circumstances in a TN system, SSB bursts generated by neighboring cells are always detectable within the corresponding SMTC window configured via the serving cell. The UE does not need to measure SSB bursts outside the corresponding configured SMTC window. However, for an NTN system, based on analysis, SSB bursts generated by neighboring cells may be outside the corresponding SMTC window configured via the serving satellite. If the UE is able to obtain the propagation delay difference between the serving satellite and neighboring satellites, then even if the SSB burst is outside the corresponding configured SMTC window, the UE can still know when to detect the actual SSB burst generated by the neighboring cell. If RAN2 does not wish to make any enhancements to the SMTC configuration of the NTN, it should allow the UE to search for SSB bursts generated by neighboring cells, even outside the corresponding configured SMTC window."

[0190] assumed:

[0191] 1) Based on Proposal 6-1 Option 2:

[0192] "The measurement gap on the UE side is derived by the UE / network (NW) based on its location and the ephemeris of candidate satellites. Since the actual timing of the SMTC window on the UE side of the cell in other satellites will change from time to time based on satellite movement, the NW needs to derive the actual timing of the measurement gap on the UE side based on the UE's location and the ephemeris of candidate satellites. Note: In this alternative, the measurement gap for each satellite remains constant."

[0193] 2) Based on the consensus in RAN1 meeting #103, it can be assumed that the UE will always obtain its location information via GNSS.

[0194] Exemplary Example: A method for determining the measurement gap of a UE without requiring the 5G radio node (gNB) to have UE location information.

[0195] 1.gNB transmits neighboring cell ephemeris tables to the UE in Radio Resource Control (RRC) signaling as part of MeasObjectNR RRC.

[0196] 2. The UE can calculate the propagation delay of neighboring cells / satellites based on the UE location and neighboring satellite ephemeris tables.

[0197] 3. If the UE detects a significant backhaul delay (RTD) > "incremental RTD" ms between the serving satellite and neighboring satellites, the UE will notify the gNB via an RRC message.

[0198] 4.gNB will then configure a measurement gap for each neighbor, or extend the measurement gap based on UE feedback.

[0199] 5. The UE calculates the neighbor's RTD after a pre-configured period "delayed reporting period" indicated by the gNB, and reports the RTD to the serving cell via RRC message if the neighbor's RTD changes > "incremental RTD Act".

[0200] refer to Figure 21 .

[0201] 6. Measurement gaps are disabled when the UE reports a neighbor delay difference threshold < "incremental RTD deAct".

[0202] RTD: Return Delay

[0203] Incremental RTD: Backhaul delay between the serving cell and neighboring cells.

[0204] Step 1:

[0205] In some embodiments of step 1, neighboring cell ephemeris tables are transmitted to the UE in the MeasObjectNR RRC.

[0206] MeasConfigNR RRC

[0207] Initially, the gNB was configured with only one measurement gap.

[0208] mgrp (measurement gap repetition period) is the period of measurement gap repetition (in milliseconds).

[0209] The NR defines periods of 20, 40, 80, and 160 ms.

[0210] `gapOffset` is the gap offset of the gap pattern. Not all 160 offset values ​​apply to all periods. Since the offset values ​​point to the start subframe within the period, their values ​​range from 0 to `mgrp-1`. For example, if the period is 40ms, the offset ranges from 0 to 39.

[0211] mgl (measuring gap length) is the length of the measuring gap in milliseconds (ms). NR defines measuring gap lengths of 1.5, 3, 3.5, 4, 5.5, and 6 ms.

[0212] mgta (Measurement Gap Timing Advance). If configured, the UE begins measurement mgta ms before the gap subframe occurs; that is, the measurement gap begins mgta ms before the end of the latest subframe that occurs immediately before the measurement gap. The timing advance can be 0.25ms (FR2) or 0.5ms (FR1).

[0213] refer to Figure 22 .

[0214] Step 2:

[0215] In some embodiments of step 2, the UE calculates the neighbor transmission delay based on the neighbor satellite ephemeris table broadcast by the UE.

[0216] I. If any broadcast neighbor is outside the SMTC measurement window configuration: Reference Figure 24 .

[0217] Note: The satellite transmission delay calculation mechanism is still being discussed in RAN1.

[0218] Step 3:

[0219] In one embodiment of step 3, the UE triggers an event "Delay A1" where the delay increment measured by the neighbor is greater than "Threshold X".

[0220] Step 4:

[0221] In one embodiment of step 4, the gNB is configured with additional MeasGap via RRC reconfiguration.

[0222] refer to Figure 25 .

[0223] Note: If neighboring cell SSBs cannot be detected by modifying mgl, mgrp, mgta, or SMTC window size / offset, the gNB will only configure additional gap measurements.

[0224] Step 5:

[0225] In some embodiments of step 5, the UE is configured with additional gap measurement.

[0226] refer to Figure 26 .

[0227] Step 6: If the delay difference between the UE and the neighboring cell and the serving cell is less than "delay threshold X".

[0228] In some embodiments of step 6, the UE triggers the event "Delay A2" where the delay increment measured by the neighbor is less than "Delay Threshold X".

[0229] Some advantages of the solution:

[0230] 1) The location where the UE is not needed at the network.

[0231] 2) The SMTC measurement window does not need to be extended to more than 5ms (a long SMTC window will reduce spectral efficiency).

[0232] 3) This scheme can be applied to adjacent satellites of LEO 600-LEO1500-GEO type at any time.

[0233] 4) The gaps are dynamically configured, which improves spectral efficiency.

[0234] 5) gNB has delay information for neighboring satellites, so gap configuration can be minimized.

[0235] 6) Acquiring adjacent satellite delay information will improve RACH and HO performance.

[0236] 7) It provides gNB with the flexibility to choose between “interval cycle implementation complexity” and “optimal resource utilization”.

[0237] appendix:

[0238] In NR, SSBs are used to measure cell quality. Each SSB consists of two synchronization signals and a physical broadcast channel with a longer transmission period compared to the Cell Reference Signal (CRS). For each cell, the SSB period can be configured within the range of 5, 10, 20, 40, 80, and 160 ms; however, the terminal does not need to measure cell quality with the same period as the SSB, and an appropriate measurement period can be configured based on channel conditions. This avoids unnecessary measurements and saves terminal power. A new SSB-based Radio Resource Management (RRM) Measurement Time Configuration (SMTC) 8-window has been introduced to inform the terminal of the SSB period and timing that must be used for cell quality measurements. The SMTC window period can be set within the same range as the SSB (i.e., 5, 10, 20, 40, 80, and 160 ms), and the window duration can be set to 1, 2, 3, 4, or 5 ms depending on the number of SSBs transmitted on the cell being measured. When the gNB notifies the UE of the SMTC window, the UE detects and measures the SSBs within that window and reports the measurement results back to the serving base station. The SS-block-based RRM measurement timing configuration, or SMTC, is the measurement window period / duration / offset information for each carrier frequency used for UE RRM measurements. For intra-frequency connectivity mode measurements, up to two measurement window periods can be configured. For idle mode measurements, one SMTC is configured for each carrier frequency. For inter-frequency connectivity mode measurements, one SMTC is configured for each carrier frequency.

[0239] refer to Figure 27 .

[0240] Using the same RF transceiver to measure neighboring cell quality or other component carriers, as well as to transmit / receive data in the serving cell, enables reduced implementation costs. However, this means that data cannot be transmitted / received in the serving cell during measurements of other cells or component carriers at different frequencies. In LTE, UE data transmission is paused during measurement gaps in the serving cell to provide an opportunity for the UE to tune its RF transceiver for neighboring cell quality measurements or measurements of other component carriers at different frequencies. NR uses the concept of measurement gaps; however, measurements are performed on the SSB, and the measurement gap configuration is improved compared to LTE. In LTE, the measurement gap length (MGL) is fixed, allowing at least one primary / secondary synchronization signal opportunity to be observed within the gap. In LTE, primary / secondary synchronization signals are transmitted every 5ms; therefore, the MGL for LTE is 6ms to allow 0.5ms of RF tuning at the beginning and end of the measurement gap. The terminal detects the synchronization signal within the MGL and identifies the cell ID and reception timing. The terminal then performs measurements on the CRS. In NR, the SMTC window duration can be set to match the SSB transmission. However, a fixed MGL may lead to a potential decrease in serving cell throughput. For example, if the SMTC window duration is 2ms and the MGL is 6ms, then the 4ms interval will not be available for data transmission and reception in the serving cell.

[0241] The measurement gap pattern is characterized by MGRP and MGL. 24 gap pattern configurations are defined in 38.133 to meet all the requirements of NR and E-UTRAN measurements.

[0242] The measurement gap patterns are shown in the table below ( Figure 28 As shown in the figure.

[0243] Configuration provided by NR RRC

[0244] In the following cases, the NR RRC is responsible for providing the measurement gap pattern configuration to the UE. This is accomplished using the MeasGapConfig IE within the MeasConfig IE and carried by the RRC reconfiguration message. The NR RRC is responsible for the following:

[0245] - In NR standalone operation (using single carrier, NR CA, and NR-DC) or in NE-DC configuration, configure gapUE or gapFR1 for the UE.

[0246] - Configure gapFR2 for the UE in any configuration (i.e., NR standalone operation) (using a single carrier, NR CA, and NR-DC) or EN-DC or NE-DC.

[0247] The MeasGapConfig IE specifies the measurement gap configuration and controls the setting / release of the measurement gap. Details of this IE are shown below ( Figure 29 );

[0248] *gapOffset: This can be defined as the offset of the gap pattern. There are approximately 160 offset values, but not all values ​​apply to all periods. The offset value points to the start subframe within that period, and its value ranges from 0 to MGRP-1. For example, if the period is 20ms, the offset range is 0 to 19.

[0249] *Measuring gap length (mgl): This is the length of the measuring gap, measured in milliseconds (ms). The measuring gap length can be 1.5, 3, 3.5, 4, 5.5, or 6 ms.

[0250] * Measurement Interval Repetition Period (mgrp): This defines the period (in milliseconds) during which the measurement interval is repeated. It can be configured to 20, 40, 80, and 160 ms.

[0251] * Measurement gap timing advance (Mgta): If configured, the UE begins measurement mgta ms before the gap subframe occurs. That is, the measurement gap begins mgta ms before the end of the latest subframe that occurred immediately before the measurement gap. The timing advance can be 0.25ms (FR2) or 0.5ms (FR1).

[0252] refer to Figure 30 .

[0253] Treatment of measurement gaps (from the perspective of Media Access Control (MAC))

[0254] During the measurement gap, the MAC entity shall, on the serving cells (multiple) within the corresponding frequency range (FR) of the measurement gap;

[0255] - The transmission of Hybrid Automatic Repeat Request (HARQ) feedback, Schedule Request (SR), and Channel State Information (CSI) is not performed.

[0256] - Do not report the sounding reference signal (SRS).

[0257] - Not transmitted on the uplink (UL) shared channel (SCH), except for Msg3.

[0258] - Not received on the downlink (DL) SCH.

[0259] - The Physical Downlink Control Channel (PDCCH) is not monitored except when the UE is waiting for Msg2 or Msg4 during the Random Access (RA) procedure.

[0260] References:

[0261] 3GPP TS38.311, which is incorporated herein by reference in its entirety.

[0262] 3GPP TS38.821, which is incorporated herein by reference in its entirety.

[0263] 3GPP TS38.811, which is incorporated herein by reference in its entirety.

[0264] 5G radio performance and management

[0265] The entire document at https: / / www.nttdocomo.co.jp / english / binary / pdf / corporate / technology / rd / technical_journal / bn / vol20_3 / vol20_3_009en.pdf is incorporated into this paper by reference.

Claims

1. A computer-readable medium comprising instructions executable by a computer to cause the computer to perform operations, the operations including: Transmit satellite ephemeris data and cell measurement window specifications to the terminal; The terminal receives an indication that the cell measurement signal will arrive at the terminal outside the time frame defined by the cell measurement window specification; Based on the propagation delay difference between the serving cell and the neighboring cell transmitting the cell measurement signal, the cell measurement window specification is modified so that the cell measurement signal will arrive at the terminal within the time frame defined by the cell measurement window specification, and the satellite provides communication with the terminal for at least one of the serving cell and the neighboring cell; as well as The modified cell measurement window specification is transmitted to the terminal. The modification of the cell measurement window specification includes: determining that the spectral efficiency of the modified cell measurement window specification is higher than a threshold spectral efficiency value.

2. The computer-readable medium of claim 1, wherein modifying the cell measurement window specification includes: Modify at least one of the period, duration, or offset.

3. The computer-readable medium according to claim 1 or 2, wherein modifying the cell measurement window specification includes: Specify additional measurement window specifications.

4. The computer-readable medium according to any one of claims 1 to 3, wherein the ephemeris data comprises: The satellite's position, the satellite's speed, and its relative cell position within the satellite.

5. The computer-readable medium according to any one of claims 1 to 4, wherein the indication comprises: This represents the delay difference value of the propagation delay difference.

6. The computer-readable medium of claim 5, wherein the operation comprises: The propagation delay difference is determined based on the ephemeris data and the geographical location of the terminal.

7. The computer-readable medium according to claim 6, wherein, The satellite relays communication between the terminal and one of the serving cell or the neighboring cell, wherein the serving cell and the neighboring cell have terrestrial locations, and The determination of the propagation delay difference is further based on the land location.

8. The computer-readable medium according to any one of claims 1 to 7, wherein the operation further comprises: Receive individual measurement window specifications from the terminal, and Based on the individual measurement window specifications, a measurement gap is provided for the terminal.

9. An apparatus comprising: The controller includes a circuit system configured to perform the following operations: Transmit satellite ephemeris data and cell measurement window specifications to the terminal; The terminal receives an indication that the cell measurement signal will arrive at the terminal outside the time frame defined by the cell measurement window specification; Based on the propagation delay difference between the serving cell and the neighboring cell transmitting the cell measurement signal, the cell measurement window specification is modified so that the cell measurement signal transmitted from the satellite will arrive at the terminal within the time frame defined by the cell measurement window specification, and the satellite provides communication with the terminal for at least one of the serving cell and the neighboring cell; as well as The modified cell measurement window specification is transmitted to the terminal. The modification of the cell measurement window specification includes: determining that the spectral efficiency of the modified cell measurement window specification is higher than a threshold spectral efficiency value.

10. The apparatus of claim 9, wherein the circuitry is further configured to modify the cell measurement window specification to modify at least one of the period, duration, or offset.

11. The apparatus of claim 9 or 10, wherein the circuit system is further configured to specify an additional measurement window specification.

12. The apparatus according to any one of claims 9 to 11, wherein the ephemeris data comprises: The satellite's position, the satellite's speed, and its relative cell position within the satellite.

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