Method for configuring time interval in mobile communication system supporting NTN, and apparatus therefor

Abstract

The present document relates to a method for configuring a time interval in a mobile communication system supporting a non-terrestrial network (NTN), and an apparatus therefor. To this end, a communication method of a user equipment (UE) comprises: receiving system information for one or more pieces of information among a synchronization signal block (SSB) transmission period, a dwell time, and a revisit time through a specific cell of a network; determining an activation time interval of the specific cell on the basis of the system information; and performing communication with the network during the activation time interval of the specific cell, wherein the SSB transmission period corresponds to one of a plurality of candidate transmission periods, and the plurality of candidate transmission periods include a period of 160 ms or more.

Description

Method for setting time intervals in a mobile communication system supporting NTN and device therefor

[0001] The following description relates to a mobile communication system supporting a Non-Terrestrial Network (NTN), and more specifically, to a method for setting a time interval in a mobile communication system supporting an NTN and performing communication based thereon, and to a device therefor.

[0002] 3GPP (3rd Generation Partnership Project), which leads the technical standards for mobile communication systems rd The Generation Partnership Project is discussing the introduction of NTN to support non-terrestrial networks such as satellites in LTE and 5G.

[0003] Discussions on NTN have been ongoing since Release 16, and Release 19 is exploring items to improve downlink coverage, improve uplink capacity / speed, support broadcast services over satellite networks, and support base station mode.

[0004] Meanwhile, various technologies are being proposed to secure the number of available beams to improve the downlink coverage of NTN.

[0005] Accordingly, in one aspect of the present invention, a method and a device for setting a time period for securing the number of available beams to improve downlink coverage in a mobile communication system supporting NTN and performing communication based thereon are proposed.

[0006] In addition, in the embodiment of the present invention, the SSB (Synchronization Signal Block) transmission cycle, dwell time, and revisit time for setting the above-described time interval are specifically examined, and a method for efficiently signaling them and a device therefor are provided.

[0007] The technology proposed below is assumed to be applicable not only to the current 5G system but also to 6G and subsequent mobile communication systems. Therefore, terms such as 'NTN', 'gNB', 'SIB (System Information Block) 1', and 'SIB 19' used in 5G may be considered as replacements for other terms in the next-generation standard corresponding to the basic concepts of satellite-based communication, network nodes corresponding to base stations, basic system information units for subsequent system information transmission, and system information units for NTN, respectively. However, for the convenience of the explanation below, terms specified in the current 5G standard may be used.

[0008] The problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0009] In one aspect of the present invention for solving the above-described problem, a method for a user equipment (UE) to perform communication with a network in a mobile communication system supporting a Non-Terrestrial Network (NTN), the method comprising: receiving system information for at least one of a SSB (Synchronization Signal Block) transmission period, a dwell time, and a revisit time through a specific cell of the network; determining an active time period of the specific cell based on the system information; and performing communication with the network during the active time period of the specific cell, wherein the SSB transmission period corresponds to one of a plurality of candidate transmission periods, and the plurality of candidate transmission periods include periods of 160 ms or more.

[0010] Meanwhile, in another aspect of the present invention, a method for a network to perform communication with a user equipment (UE) in a mobile communication system supporting NTN is proposed, comprising: setting a beam hopping scheme for a plurality of cells supported by the network; transmitting system information for at least one of an SSB transmission period, a residence time, and a revisit time through a specific cell among the plurality of cells, to the user equipment according to the beam hopping scheme; and performing communication with the user equipment during an activation time period of the specific cell in response to the system information, wherein the SSB transmission period corresponds to one of a plurality of candidate transmission periods, and the plurality of candidate transmission periods include periods of 160 ms or more.

[0011] Meanwhile, in another aspect of the present invention, a user equipment (UE) for performing communication with a network in a mobile communication system supporting NTN is proposed, comprising: at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, wherein the operations include receiving system information for one or more of an SSB transmission period, a residence time, or a revisit time through a specific cell of the network; determining an active time period of the specific cell based on the system information; and performing communication with the network during the active time period of the specific cell, wherein the SSB transmission period corresponds to one of a plurality of candidate transmission periods, and the plurality of candidate transmission periods include periods of 160 ms or more.

[0012] Meanwhile, in another aspect of the present invention, a network for performing communication with a user equipment (UE) in a mobile communication system supporting NTN is proposed, comprising: at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, wherein the operations include: setting a beam hopping scheme for a plurality of cells supported by the network; transmitting system information for at least one of an SSB transmission period, a residence time, and a revisit time through a specific cell among the plurality of cells according to the beam hopping scheme to the user equipment; and performing communication with the user equipment during an active time period of the specific cell in response to the system information, wherein the SSB transmission period corresponds to one of a plurality of candidate transmission periods, and the plurality of candidate transmission periods include periods of 160 ms or more.

[0013] In one embodiment, the system information may include information about the SSB transmission period, the residence time, and the revisit time, and if the SSB transmission period is shorter than the residence time, the SSB is repeatedly received at the SSB transmission period within the residence time, and if the SSB transmission period is longer than the residence time, the revisit time may be considered to be equal to the SSB transmission period.

[0014] In another embodiment, the system information may include information about the SSB transmission period and the residence time, and the revisit time may be set to be the same as the SSB transmission period.

[0015] In another embodiment, the system information may include information about the residence time, the SSB transmission period may be set to a default value, and the revisit time may be set to be the same as the SSB transmission period.

[0016] In another embodiment, the system information may include information about the residence time and the revisit time, and the SSB transmission cycle may be set to a default value or the revisit time value.

[0017] In another embodiment, the system information may include beam footprint setting information for the NTN, and based on the beam footprint setting information, one or more of the SSB transmission period, the residence time, or the revisit time may be derived.

[0018] At this time, the beam footprint setting information for the NTN may include one or more of the total number of beam footprints for the NTN, the number of beam footprints that can be activated simultaneously, or the cell activation ratio.

[0019] In another embodiment, the system information may include uplink / downlink pattern information of TDD (Time Division Duplex), and based on the uplink / downlink pattern information of the TDD, one or more of the SSB transmission period, the residence time, or the revisit time may be derived.

[0020] At this time, if the uplink / downlink pattern information of the TDD sets N patterns (N is a natural number), the SSB transmission period can be aligned with the N pattern periods.

[0021] In addition, the system information may additionally include a parameter for setting the residence time, and the residence time may be determined by the parameter and a period according to the uplink / downlink pattern information of the TDD.

[0022] According to the embodiments of the present invention as described above, downlink coverage can be improved in an NTN-based system through time interval setting.

[0023] Additionally, information about SSB transmission cycles, dwell times, and revisit times for these time interval settings can be efficiently signaled.

[0024]

[0025] The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention belongs from the description below.

[0026] Figure 1 is a diagram illustrating the elements of NTN discussed in 3GPP.

[0027] Figure 2 is a drawing to explain the concept of the number of beams available in a system supporting NTN.

[0028] FIG. 3 is a diagram for explaining communication between a UE and a network in a mobile communication system supporting NTN according to one embodiment of the present invention.

[0029] FIG. 4 is a diagram for explaining the concept of SSB transmission cycle and residence time borrowed in one embodiment of the present invention.

[0030] FIGS. 5 to 7 are drawings for explaining time / frequency tracking errors when extending an SSB transmission cycle according to one embodiment of the present invention.

[0031] FIG. 8 is a diagram for explaining UE connection delay when extending an SSB transmission cycle according to one embodiment of the present invention.

[0032] FIG. 9 and FIG. 10 are drawings for explaining SSB transmission settings according to one embodiment of the present invention.

[0033] FIG. 11 is a drawing for explaining the concept of revisit time according to one embodiment of the present invention.

[0034] FIG. 12 is a diagram for explaining a method for describing an SSB transmission cycle, residence time, and revisit time according to a first embodiment of the present invention.

[0035] FIG. 13 is a diagram for explaining a method for describing an SSB transmission cycle, residence time, and revisit time according to a second embodiment of the present invention.

[0036] FIG. 14 is a diagram for explaining a method for describing an SSB transmission cycle, residence time, and revisit time according to a third embodiment of the present invention.

[0037] FIG. 15 and FIG. 16 are drawings for explaining a method of explaining an SSB transmission cycle, residence time, and revisit time according to a fourth embodiment of the present invention.

[0038] Figure 17 illustrates a wireless device to which the present technology can be applied.

[0039] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In addition, in the drawings, parts irrelevant to the description have been omitted to clearly explain the present invention, and similar parts have been designated with similar reference numerals throughout the specification.

[0040] Throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0041]

[0042] As described above, one aspect of the present invention examines a method for securing the number of available beams in a system supporting NTN. To this end, we first examine the current state of NTN and the discussions surrounding downlink improvements within 3GPP.

[0043] Figure 1 is a diagram illustrating the elements of NTN discussed in 3GPP.

[0044] As illustrated in Figure 1, NTN generally includes the following elements:

[0045] First, it may include one or more gateways (110) that connect the NTN to a public data network. The satellite (120) may be implemented as a satellite or an Unmanned Aircraft System (UAS) as illustrated in FIG. 1, and the satellites may be classified into GEO satellites and non-GEO satellites.

[0046] A GEO satellite (120) may be served by one or more gateways (110) deployed across the satellite's target range (e.g., regional or continental range). It may be assumed that a UE (130) of a cell is served by a gateway (110).

[0047] A non-GEO satellite (120) can be successively served by one or more gateways (110) at a time. The system can ensure service and feeder link continuity between successive serving gateways for a sufficient time to perform mobility anchoring and handover.

[0048] A feeder link or wireless link may be established between the gateway (110) and the satellite (or UAS platform) (120). A service link or wireless link may be established between the UE (130) and the satellite (or UAS platform) (120).

[0049] Meanwhile, the beams generated by a satellite (or UAS platform) (120) typically generate multiple beams for a given service area bounded by its field of view. The footprints (140) of the beams may be generally elliptical, as illustrated in FIG. 1, but need not be limited thereto. The field of view of the satellite (or UAS platform) may depend on the onboard antenna diagram and the minimum elevation angle.

[0050] There may be different types of satellites (or UAS platforms) (120). The following table exemplifies types of NTN platforms.

[0051]

[0052] PlatformsAltitude RangeOrbitTypical beam footprint sizeLow-Earth Orbit(LEO) satellite300-1500 kmCircular around the earth100 - 1000 kmMedium-Earth Orbit (MEO) satellite7000 - 25000 km100 - 1000 kmGeostationary Earth Orbit (GEO) satellite35 786 kmnotional station keeping position fixed in terms of terms of elevation / azimuth with respect to a given earth point200 - 3500 kmUAS platform (including HAPS)8 - 50 km (20 km for HAPS)5 - 200 kmHigh Elliptical Orbit (HEO) satellite400 - 50000 kmElliptical around the earth200 - 3500 km

[0053] Typically, GEO satellites and UAS are used to provide continental, regional, or local services, while constellations of LEO and MEO satellites are used to provide services in both the Northern and Southern Hemispheres. In some cases, these constellations can provide global coverage, including polar regions.

[0054]

[0055] Figure 2 is a drawing to explain the concept of the number of beams available in a system supporting NTN.

[0056] Since SSB can only use a limited number of indices depending on the sub-carrier spacing, it is not possible to assign an independent index to every beam pattern in systems that use more than 1,000 beam footprints, such as satellite communications.

[0057] Therefore, in order to utilize all beam footprints within the existing specifications, it is desirable to increase the maximum number of operable beam footprints through beam hopping, which changes the beam footprint mapped to each SSB index when transmitting SSB in 20 ms units. For example, if beam hopping is not used, the number of usable beam footprints in a base station using four SSB indices is 'the number of SSB indices x the number of activated beams'.

[0058] Here, the number of active beams is assumed to be the maximum number of beams that can satisfy the minimum signal level or higher, and in the example of utilizing four SSB indices as shown in Fig. 2, the number of active beams of the satellite (N Sat When the number of activeBeams is 16, the number of operable beam footprints is 64 (=4 x 16).

[0059] In addition, in embodiments of the present invention, in order to efficiently increase the number of beams that can be supported, it is assumed that the transmission cycle of SSB is extended from the existing 20 ms to 80 ms, 160 ms, 320 ms, etc., and the transmission cycle of SSB for such NTN service can be referred to as an 'extended cycle'.

[0060] FIG. 3 is a diagram for explaining communication between a UE and a network in a mobile communication system supporting NTN according to one embodiment of the present invention.

[0061] In one embodiment of the present invention, the above-described extension period corresponds to one of a plurality of candidate transmission periods, wherein it is assumed that the plurality of candidate transmission periods include periods greater than or equal to 160 ms, which is the maximum transmission period of conventional 5G. For example, the above-described extension period may be set to 320 ms or greater.

[0062] The network supporting NTN in FIG. 3 may be a node corresponding to a specific cell in the mobile communication system described above with respect to FIG. 2. In addition, the network supporting NTN in FIG. 3 may determine a beam hopping pattern by considering the number of operating cells, the number of activated beams, etc., as described above with respect to FIG. 2 (S310).

[0063] Based on the beam hopping pattern determined in this manner, the network can transmit system information (SI) to the UE (S320). At this time, the system information corresponds to system information for one or more of the SSB transmission period, dwell time, or revisit time. At this time, the meaning of system information 'for' SSB transmission period, dwell time, or revisit time refers to a concept that includes information that directly and explicitly includes the relevant information, or that allows the SSB transmission period, dwell time, or revisit time to be inferred based on other information in the system information.

[0064] A UE that receives such system information can determine an activation time interval of a specific cell (Cell #n) based on the received system information (S330) and perform communication with the network based on this (S340).

[0065]

[0066] Below, the concept of extending the above-described SSB transmission cycle is explained in more detail.

[0067] FIG. 4 is a diagram for explaining the concept of SSB transmission cycle and residence time borrowed in one embodiment of the present invention.

[0068] When transmitting a downlink signal in a beam hopping manner in a mobile communication system using NTN, SSB and / or SI can be transmitted in units of a specific active beam (active beam -1) as illustrated in FIG. 4. The example illustrated in FIG. 4 assumes that the SSB transmission period (410) is set to 160 ms.

[0069] Within the SSB transmission cycle (410), SSB / SI can be Time Domain Multiplexed (TDM) in units of 20 ms, and the 20 ms can be referred to as a TDM gap (TDM gap; 430). This TDM gap (430) can correspond to a footprint corresponding to each SSB, and data transmission and reception can be performed during the residence time (420) other than the SSB / SI transmission section in each TDM gap (430a, 430b).

[0070]

[0071] FIGS. 5 to 7 are drawings for explaining time / frequency tracking errors when extending an SSB transmission cycle according to one embodiment of the present invention.

[0072] Specifically, FIG. 5 illustrates the transmission timing of SSB, SIB 1 / 19 and the transmission timing of downlink control channel (PDCCH) / downlink shared channel (PDSCH) for each UE when 640 ms is applied as an extension period, and FIG. 6 and FIG. 7 illustrate the time / frequency tracking error of each signal accordingly.

[0073] As illustrated in FIG. 5, SSB1 and SUB19 transmitted through common signal sweeping within a 10 ms interval have no time / frequency tracking error as illustrated at 610 and 620 in FIG. 6, respectively. In contrast, PDCCH / PDSCH may experience a certain level of time / frequency tracking error as illustrated at 710 and 720 in FIG. 7 due to the influence of the extended period, but the level of the above errors is judged to be tolerable in terms of securing downlink coverage as described above with respect to FIG. 2.

[0074] FIG. 8 is a diagram for explaining UE connection delay when extending an SSB transmission cycle according to one embodiment of the present invention.

[0075] As illustrated in FIG. 8, it may take approximately 75 ms for one UE to transition from RRC_INACTIVE state to RRC_CONNECTED state.

[0076] If, in one embodiment of the present invention, an extended period is applied, additional time delay may occur accordingly.

[0077] For example, if the SSB transmission period is extended to 640 ms, the UE's network access delay time is (640 + 75 =) 715 ms, which can be considered a tolerable level for the downlink coverage expansion of the NTN described above.

[0078] Accordingly, in one embodiment of the present invention, the SSB transmission period is set to be scalable as described above, and specifically, it is proposed to set it to one of a plurality of candidate SSB transmission periods and notify the UE through signaling, and at this time, the candidate SSB transmission period includes a period of 160 ms or more, and can include up to 320 ms and 640 ms as in the examples described above.

[0079]

[0080] FIG. 9 and FIG. 10 are drawings for explaining SSB transmission settings according to one embodiment of the present invention.

[0081] In the NR system, the SSB transmission period is set to any one of the candidate SSB transmission periods of 5 ms, 10 ms, 20 ms, 40 ms, 80 ms, and 160 ms, but generally, the 20 ms transmission period is most commonly used, and Fig. 9 illustrates the SSB transmission form according to this. The setting for this is illustrated in the structure that signals through ssb-periodicityServingCell when transmitting the SSB transmission period as shown in Fig. 10 through the ServingCellConfigCommon information element of SIB 1.

[0082] However, in one embodiment of the present invention, unlike the current NR system, it is proposed to design the system so that an extended period can be applied, and accordingly, as shown in FIG. 10, an extended period of 320 ms, 640 ms, etc. can be additionally included in the candidate SSB transmission period.

[0083] Meanwhile, as illustrated in FIG. 9, transmission of SSBs within an SSB burst can be performed within a 5 ms window. As illustrated in FIG. 9, the time domain pattern for transmitting SSBs within an SSB burst can vary depending on the subcarrier spacing and frequency band (910a - 950).

[0084] The maximum number of transmitted SSBs within an SSB burst (i.e., a 5 ms period) can be set to 4 in the band up to 3 GHz, 8 in the 3-6 GHz band, and 64 in the 6-52.6 GHz band. However, the actual number of transmitted SSBs within this upper limit range can be set separately.

[0085] In the example of FIG. 9, 910a exemplarily shows a case where the subcarrier spacing (SCS) is 15 kHz in a band below 3 GHz, 910b exemplarily shows a case where the SCS is 15 kHz in a band between 3 and 6 GHz, 920a exemplarily shows a case where the SCS is 30 kHz in a band below 3 GHz, 920b exemplarily shows a case where the SCS is 30 kHz in a band between 3 and 6 GHz, 930a exemplarily shows a case where the SCS is 30 kHz in a band below 3 GHz, 930b exemplarily shows a case where the SCS is 30 kHz in a band between 3 and 6 GHz, 940 exemplarily shows a case where the SCS is 120 kHz in a band below 6 GHz, and 950 exemplarily shows a case where the SCS is 240 kHz in a band above 6 GHz.

[0086] Although the example of FIG. 9 illustrates various transmission patterns according to the band and SCS, it is not excluded that the SSB transmission pattern may vary by additional parameters in one embodiment of the present invention.

[0087] In one embodiment of the present invention, it is assumed that the UE operates under the assumption of a default SSB transmission period before receiving system information (SI corresponding to SIB 1 of NR) from the network regarding which SSB transmission period among the extended SSB transmission period candidates as illustrated in FIG. 10 is set. For example, the default SSB transmission period may be 20 ms as illustrated in FIG. 9 and FIG. 10 , and a different default transmission period may also be used in the NTN.

[0088]

[0089] FIG. 11 is a drawing for explaining the concept of revisit time according to one embodiment of the present invention.

[0090] Assuming a scenario using LEO600km Set1-1, which is currently being considered for use in FR1 in NTN, a total of 1058 beam footprints are set, but since a maximum of 106 beam footprints can be supported simultaneously, it can be seen that only about 10% of the beam footprints can be supported simultaneously.

[0091] Accordingly, it is desirable to secure downlink coverage by revisiting each cell (i.e., Cell#1, Cell#2, Cell#3, etc.) by applying beam hopping method, and therefore, as shown in Fig. 11, the time interval until revisiting a specific cell (Cell#1) is called revisit time (T rev ) can be defined. In the example of Fig. 11, this revisit time (T rev ) is set to 320 ms.

[0092] This revisit time (T rev ) is the time for which the cell (Cell#1) is activated, called the residence time (T dwell ) can be defined as, and in the example of Fig. 11, this residence time (T dwell ) is set to 20 ms. Each frame is divided into a frame interval (T frame ) can be transmitted based on the frame interval (T), and Fig. 11 shows the frame interval (T frame ) is set to 10 ms.

[0093] In the example of Fig. 11, the SSB transmission period is also the revisit time (T rev ) can be seen to be set to 320 ms, the same as the SSB transmission cycle. In this way, the revisit time (T rev ) may be the same as, but may be set differently as described below.

[0094] Below, the SSB transmission cycle and dwell time (T dwell ), or revisit time (T rev) describes a specific example of configuring system information for one or more pieces of information.

[0095]

[0096] FIG. 12 is a diagram for explaining a method for describing an SSB transmission cycle, residence time, and revisit time according to a first embodiment of the present invention.

[0097] In this embodiment, it is proposed to explicitly set the SSB transmission period, residence time, and revisit time and transmit them to the UE. That is, as shown in 1210 of FIG. 12, the SSB transmission period (T ssb ) is 20 ms, and the residence time (T dwell ) is 40 ms, and the revisit time (T rev ) is set to 320 ms, each piece of information can be explicitly configured as system information and transmitted to the UE via RRC signaling.

[0098] If, as shown in 1210 of Fig. 12, the SSB transmission cycle (T ssb ) is the residence time (T dwell ), the SSB has a residence time (T dwell ) within the SSB transmission cycle (T ssb ) can be repeatedly transmitted.

[0099] As another example, as shown in 1220 of FIG. 12, the revisit time (T rev ) is the SSB transmission period (T ssb ) is set as the same as the SSB transmission period (T ), and accordingly, the SI transmitted to the UE is set as the SSB transmission period (T ) ssb ) and residence time (T dwell ) can be set to include information.

[0100] As shown in 1220 of Fig. 12, the SSB transmission period (T ssb ) is the residence time (T dwell ), the revisit time (T rev) can also be set to be considered the same as the SSB transmission period.

[0101]

[0102] FIG. 13 is a diagram for explaining a method for describing an SSB transmission cycle, residence time, and revisit time according to a second embodiment of the present invention.

[0103] Specifically, in one embodiment of the present invention, the residence time (T) is transmitted to the SI to the UE. dwell ) and includes the SSB transmission period (T ssb ) and revisit time (T rev ) is assumed to be set to the default value.

[0104] Specifically, the SSB transmission period (T ssb ) is set to either 160 ms or 320 ms as a default value, which can be determined by the operating frequency. In addition, the revisit time (T rev ) is the SSB transmission period (T ssb ) can be set to the same value.

[0105] Meanwhile, in another embodiment of the present invention, the residence time (T) is transmitted to the SI to the UE. dwell ) and revisit time (T rev ) and includes the SSB transmission period (T ssb ) can be operated assuming the default setting value (20 ms) as shown in 1310 of Fig. 13. In this case, the set residence time (T) as shown in 1310 of Fig. 13 dwell ) within the SSB cycle (T ssb ) is repeatedly transmitted, and this pattern is called the revisit time (T rev ) can be set to repeat periodically. In addition, in this case, the revisit time (T rev ) is the SSB transmission period (T ssb ) is set to an integer multiple of .

[0106] Meanwhile, in another embodiment of the present invention, the residence time (T) is transmitted to the SI to the UE. dwell ) and revisit time (T rev ) and includes the SSB transmission period (T ssb ) is the revisit time (T) as shown in 1320 of Fig. 13. rev ) can be set to a value. In this case, the residence time (T ) as shown in 1320 of Fig. 13 dwell ) SSB can be transmitted only once within the interval.

[0107]

[0108] FIG. 14 is a diagram for explaining a method for describing an SSB transmission cycle, residence time, and revisit time according to a third embodiment of the present invention.

[0109] Specifically, in this embodiment, the system information includes beam footprint setting information for NTN, and based on this beam footprint setting information, the SSB transmission period (T ssb ), residence time (T dwell ), and / or revisit time (T rev ) is proposed. In NR, beam footprint configuration information can be transmitted through SIB 19, but the name of the system information transmitting configuration information for NTN may be specified differently in the next-generation standard.

[0110] At this time, the beam footprint setting information is the total number of beam footprints for NTN (N total ), the number of beam footprints (or number of cells) that can be activated simultaneously (N beam ), or may include one or more pieces of information on a cell activation ratio (K) defined as follows.

[0111] [Mathematical Formula 1]

[0112] K = N beam / N total or K'= N total / N beam

[0113] Based on the above information, cell activation time patterns can be determined.

[0114] As an example, the residence time can be determined by the SSB cycle setting information * K value as follows.

[0115] [Equation 2]

[0116] T dwell = T ssb * K

[0117] In the example of Fig. 14, T ssb =320ms, when K=0.1, T dwell = can be determined as 32ms. In this case, it is assumed that the revisit time is equal to the SSB transmission cycle.

[0118] As another example, the revisit time (T) is as follows: rev ) and the residence time (T dwell ) / K can be derived.

[0119] [Equation 3]

[0120] T rev = T dwell / K

[0121] For example, T dwell If =20ms, K=10%, T rev =200ms can be calculated. At this time, the SSB period (T ssb ) is the revisit time (T rev ) can be assumed to be identical.

[0122]

[0123] FIG. 15 and FIG. 16 are drawings for explaining a method of explaining an SSB transmission cycle, residence time, and revisit time according to a fourth embodiment of the present invention.

[0124] Specifically, in the present embodiment, the system information includes uplink / downlink pattern information (TDD UL / DL pattern) of Time Division Duplex (TDD), and based on the uplink / downlink pattern information of TDD, it is proposed to derive at least one of an SSB transmission period, a dwell time, or a revisit time. For example, at least one of the SSB transmission period, a dwell time, or a revisit time may be set to an integer multiple of the TDD uplink / downlink pattern period.

[0125] Figure 15 illustrates an example of aligning the SSB transmission period, residence time, and / or revisit time to the period setting information (dl-UL-TransmissionPeriodicity) when a TDD uplink / downlink pattern is set according to the corresponding RRC parameter (tdd-UL-DL-ConfigCommon).

[0126] In addition, FIG. 16 illustrates an example in which, when two TDD uplink / downlink patterns are set according to corresponding RRC parameters (tdd-UL-DL-ConfigCommon), the SSB transmission period, residence time, and / or revisit time are set to align with the entire period that combines pattern 1 and pattern 2.

[0127] Meanwhile, the system information can set integer values ​​for determining the residence time and revisit time, respectively. Integer value for determining the residence time (K dwell ) is set, the residence time can be determined as follows.

[0128] [Equation 4]

[0129] T dwell = P tdd *K dwell

[0130] Additionally, an integer value (K) for determining the revisit time rev ) is set, the revisit time can be determined as follows.

[0131] [Equation 5]

[0132] T rev = P tdd *K rev

[0133] At this time, T ssb = T rev Assuming that, or an integer value (K) for determining the SSB period ssb ) can be set separately and determined as follows.

[0134] [Equation 6]

[0135] T ssb = P tdd *K ssb

[0136] In another embodiment, an integer value may be set for determining the dwell time, and the revisit time may be assumed to be the SSB transmission cycle.

[0137] That is, the integer value (K) for determining the residence time dwell ) is set, the residence time can be determined as follows.

[0138] [Equation 7]

[0139] T dwell = P tdd *K dwell

[0140] At this time, the SSB cycle can use the default value or a separately set value.

[0141] Additionally, the revisit time can be determined as follows:

[0142] [Equation 8]

[0143] T rev = T ssb

[0144]

[0145] Figure 17 illustrates a wireless device to which the present technology can be applied.

[0146] Referring to FIG. 17, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals via various wireless access technologies (e.g., LTE, NR, 6G). Here, the first wireless device (100) and the second wireless device (200) can each correspond to the UE and network of FIG. 3.

[0147] A first wireless device (100) includes one or more processors (102) and one or more memories (104), and may further include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memories (104) and / or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (102) may process information in the memory (104) to generate first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver (106). In addition, the processor (102) may receive a wireless signal including second information / signal via the transceiver (106), and then store information obtained from signal processing of the second information / signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE E-UTRA, 5G NR). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals via one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In the present invention, a wireless device may also mean a communication modem / circuit / chip.

[0148] The second wireless device (200) includes one or more processors (202), one or more memories (204), and may further include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memories (204) and / or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (202) may process information in the memory (204) to generate third information / signals, and then transmit a wireless signal including the third information / signals via the transceivers (206). Furthermore, the processor (202) may receive a wireless signal including fourth information / signals via the transceivers (206), and then store information obtained from signal processing of the fourth information / signals in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may store software code including commands for performing some or all of the processes controlled by the processor (202) or for performing the descriptions, functions, procedures, proposals, methods and / or operation flowcharts disclosed in this document. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE E-UTRA, 5G NR). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In the present invention, a wireless device may also mean a communication modem / circuit / chip.

[0149] Hereinafter, the hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed herein, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein.

[0150] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software configured to perform one or more processors (102, 202) or stored in one or more memories (104, 204) and executed by one or more processors (102, 202). The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0151] One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories (104, 204) may be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0152] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or flowcharts of this document, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts of this document, from one or more other devices. For example, one or more transceivers (106, 206) can be connected to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein, via one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0153]

[0154] The detailed description of the preferred embodiments of the present invention disclosed above has been provided to enable those skilled in the art to implement and practice the present invention. While the above description has been made with reference to preferred embodiments of the present invention, those skilled in the art will appreciate that various modifications and variations can be made to the present invention without departing from the scope of the present invention. For example, those skilled in the art can utilize the individual components described in the above-described embodiments in combination with each other.

[0155] Accordingly, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0156] The method for setting a time interval and the device therefor in a mobile communication system supporting NTN according to the embodiments of the present invention as described above are suitable for use in a communication environment using NTN discussed in 3GPP, but can also be widely used in an environment where satellite-based communication is used in a communication method other than 3GPP.

Claims

1. In a mobile communication system supporting NTN (Non-Terrestrial Network), a method for a user equipment (UE) to perform communication with a network, Receive system information for one or more of a SSB (Synchronization Signal Block) transmission period, a dwell time, or a revisit time through a specific cell of the above network; Based on the above system information, determining the activation time interval of the specific cell; and Including performing communication with the network during the activation time interval of the specific cell, A communication method of a UE, wherein the above SSB transmission period corresponds to one of a plurality of candidate transmission periods, and the plurality of candidate transmission periods include periods of 160 ms or more.

2. In paragraph 1, The above system information is, Includes information about the SSB transmission cycle, the residence time, and the revisit time, If the above SSB transmission cycle is shorter than the dwell time, the SSB is repeatedly received with the above SSB transmission cycle within the dwell time, A communication method of a UE, wherein if the SSB transmission period is longer than the residence time, the revisit time is considered to be the same as the SSB transmission period.

3. In paragraph 1, The above system information is, Contains information about the above SSB transmission cycle and the above residence time, A communication method of a UE, wherein the above revisit time is set to be the same as the above SSB transmission period.

4. In paragraph 1, The above system information is, Includes information about the above stay time, The above SSB transmission cycle is set to the default value, A communication method of a UE, wherein the above revisit time is set to be the same as the above SSB transmission period.

5. In paragraph 1, The above system information is, Includes information about the above stay time and the above revisit time, A communication method of a UE, wherein the above SSB transmission cycle is set to a default value or the above revisit time value.

6. In paragraph 1, The above system information includes beam footprint setting information for the NTN, A communication method of a UE, wherein one or more of the SSB transmission period, the residence time, or the revisit time is derived based on the beam footprint setting information.

7. In paragraph 6, The beam footprint setting information for the above NTN is: A communication method of a UE, comprising one or more pieces of information including the number of total beam footprints for the NTN, the number of simultaneously active beam footprints, or the cell activation ratio.

8. In paragraph 1, The above system information includes uplink / downlink pattern information of TDD (Time Division Duplex), A communication method of a UE, which derives at least one of the SSB transmission period, the residence time, or the revisit time based on the uplink / downlink pattern information of the TDD.

9. In paragraph 8, A communication method of a UE, wherein when the uplink / downlink pattern information of the above TDD sets N patterns (N is a natural number), the SSB transmission period is aligned with the N pattern periods.

10. In paragraph 8, The above system information additionally includes parameters for setting the above residence time, A communication method of a UE, wherein the above-mentioned residence time is determined by the cycle and the above-mentioned parameter according to the uplink / downlink pattern information of the TDD.

11. In a mobile communication system supporting NTN (Non-Terrestrial Network), a method for a network to communicate with a user equipment (UE), Setting a beam hopping method for multiple cells supported by the above network; According to the beam hopping method, system information for one or more of the SSB (Synchronization Signal Block) transmission cycle, dwell time, or revisit time through a specific cell among the plurality of cells is transmitted to the user device; and In response to the above system information, performing communication with the user device during the activation time period of the specific cell, A communication method of a network, wherein the above SSB transmission period corresponds to one of a plurality of candidate transmission periods, and the plurality of candidate transmission periods include periods of 160 ms or more.

12. In a user equipment (UE) that performs network communication in a mobile communication system supporting NTN (Non-Terrestrial Network), at least one processor; and At least one computer memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations; The above actions are, Receive system information for one or more of a SSB (Synchronization Signal Block) transmission period, a dwell time, or a revisit time through a specific cell of the above network; Based on the above system information, determining the activation time interval of the specific cell; and Including performing communication with the network during the activation time interval of the specific cell, The above SSB transmission period corresponds to one of a plurality of candidate transmission periods, wherein the plurality of candidate transmission periods include periods of 160 ms or more. User device.

13. In a network that performs communication with a user equipment (UE) in a mobile communication system supporting NTN (Non-Terrestrial Network), at least one processor; and At least one computer memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations; The above actions are, Setting a beam hopping method for multiple cells supported by the above network; According to the beam hopping method, system information for one or more of the SSB (Synchronization Signal Block) transmission cycle, dwell time, or revisit time through a specific cell among the plurality of cells is transmitted to the user device; and In response to the above system information, performing communication with the user device during the activation time period of the specific cell, A network wherein the above SSB transmission period corresponds to one of a plurality of candidate transmission periods, wherein the plurality of candidate transmission periods include periods of 160 ms or longer.

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