WO2023014277A1 - Validité de données d'éphémérides pour des réseaux non terrestres - Google Patents

Validité de données d'éphémérides pour des réseaux non terrestres Download PDF

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Publication number
WO2023014277A1
WO2023014277A1 PCT/SE2022/050745 SE2022050745W WO2023014277A1 WO 2023014277 A1 WO2023014277 A1 WO 2023014277A1 SE 2022050745 W SE2022050745 W SE 2022050745W WO 2023014277 A1 WO2023014277 A1 WO 2023014277A1
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Prior art keywords
ephemeris data
network
validity
satellites
satellite
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PCT/SE2022/050745
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English (en)
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Talha KHAN
Xingqin LIN
Zhipeng LIN
Johan Rune
Jonas SEDIN
Chao He
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Telefonaktiebolaget Lm Ericsson (Publ)
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Publication of WO2023014277A1 publication Critical patent/WO2023014277A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/185—Space-based or airborne stations; Stations for satellite systems
    • H04B7/1853—Satellite systems for providing telephony service to a mobile station, i.e. mobile satellite service
    • H04B7/18539—Arrangements for managing radio, resources, i.e. for establishing or releasing a connection
    • H04B7/18543—Arrangements for managing radio, resources, i.e. for establishing or releasing a connection for adaptation of transmission parameters, e.g. power control
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W56/00—Synchronisation arrangements
    • H04W56/001—Synchronization between nodes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/185—Space-based or airborne stations; Stations for satellite systems
    • H04B7/1853—Satellite systems for providing telephony service to a mobile station, i.e. mobile satellite service
    • H04B7/18545—Arrangements for managing station mobility, i.e. for station registration or localisation

Definitions

  • Embodiments of the present disclosure are directed to wireless communications and, more particularly, ephemeris data validity for non-terrestrial networks (NTNs).
  • NTNs non-terrestrial networks
  • EPS evolved packet system
  • LTE long-term evolution
  • EPC evolved packet core
  • NB-IoT narrowband Internet of Things
  • LTE-M LTE for machines
  • mMTC massive machine type communications
  • 3GPP also specifies the 5G system (5GS), which is a new generation radio access technology serving use cases such as enhanced mobile broadband (eMBB), ultra-reliable and low latency communication (URLLC) and mMTC.
  • 5G includes the new radio (NR) access stratum interface and the 5G Core Network (5GC).
  • NR new radio
  • GC 5G Core Network
  • the NR physical and higher layers reuse parts of the LTE specification, and to that add needed components when motivated by the new use cases.
  • One such component is a sophisticated framework for beam forming and beam management to extend the support of the 3 GPP technologies to a frequency range going beyond 6 GHz.
  • 3GPP release 15 3GPP started the work to prepare NR for operation in a Non-Terrestrial Network (NTN) (e.g., satellite communications). The work was performed within the study item “NR to support Non-Terrestrial Networks” and resulted in TR 38.811.
  • NTN Non-Terrestrial Network
  • 3GPP release 16 the work to prepare NR for operation in an NTN network continued with the study item “Solutions for NR to support Non-Terrestrial Network”.
  • 3GPP release 17 contains both a work item on NR NTN and a study item on NB-IoT and LTE-M support for NTN.
  • a satellite radio access network usually includes the following components.
  • a satellite that refers to a space-borne platform.
  • An earth-based gateway that connects the satellite to a base station or a core network, depending on the choice of architecture.
  • a feeder link that refers to the link between a gateway and a satellite.
  • An access link that refers to the link between a satellite and a UE.
  • a satellite may be categorized as low earth orbit (LEO), medium earth orbit (MEO), or geostationary earth orbit (GEO) satellite.
  • LEO includes typical heights ranging from 250 - 1,500 km, with orbital periods ranging from 90 - 120 minutes.
  • MEO includes typical heights ranging from 5,000 - 25,000 km, with orbital periods ranging from 3 - 15 hours.
  • GEO includes height at about 35,786 km, with an orbital period of 24 hours.
  • the transparent payload also referred to as bent pipe architecture
  • the satellite forwards the received signal between the terminal and the network equipment on the ground with only amplification and a shift from uplink frequency to downlink frequency.
  • the transparent payload architecture means that the gNB is located on the ground and the satellite forwards signals/data between the gNB and the UE.
  • the satellite includes on-board processing to demodulate and decode the received signal and regenerate the signal before sending it back to the earth.
  • the regenerative payload architecture means that the gNB is located in the satellite.
  • FIGURE 1 is a network diagram illustrating an example architecture of a satellite network with bent pipe transponders.
  • the gNB may be integrated in the gateway or connected to the gateway via a terrestrial connection (wire, optic fiber, wireless link).
  • a communication satellite typically generates several beams over a given area.
  • the footprint of a beam is usually in an elliptic shape, which has been traditionally considered as a cell.
  • the footprint of a beam is also often referred to as a spotbeam.
  • the footprint of a beam may move over the earth surface with the satellite movement or may be earth fixed with some beam pointing mechanism used by the satellite to compensate for its motion.
  • the size of a spotbeam depends on the system design, which may range from tens of kilometers to a few thousands of kilometers.
  • Propagation delay is an important aspect of satellite communications that is different from the delay expected in a terrestrial mobile system.
  • the round-trip delay may, due to the orbit height, range from tens of ms in the case of LEO to several hundreds of ms for GEO. This can be compared to the round-trip delays catered for in a cellular network which are limited to 1 ms.
  • the propagation delay may also be highly variable due to the high velocity of the LEO and MEO satellites and change in the order of 10 - 100 ps every second, depending on the orbit altitude and satellite velocity.
  • the long propagation delay means that the timing advance (TA) the UE uses for its uplink transmissions is essential and has to be much greater than in terrestrial networks for the uplink and downlink to be time aligned at the gNB, as is the case in NR and LTE.
  • TA timing advance
  • RA random access
  • pre-compensation TA The TA the UE uses for the RA preamble transmission is called “pre-compensation TA”.
  • Various proposals are considered for how to determine the precompensation TA, all of which involves information originating both at the gNB and at the UE.
  • One proposal is broadcast of a “common TA” which is valid at a certain reference point, e.g., a center point in the cell.
  • the UE calculates how its own pre-compensation TA deviates from the common TA, based on the difference between the UE’s own location and the reference point together with the position of the satellite.
  • the UE acquires its own position using global navigation satellite system (GNSS) measurements and the UE obtains the satellite position using satellite orbital data (including satellite position at a certain time) broadcast by the network.
  • GNSS global navigation satellite system
  • Another proposal is the UE autonomously calculates the propagation delay between the UE and the satellite, based on the UE’s and the satellite’s respective positions, and the network/gNB broadcasts the propagation delay on the feeder link, i.e., the propagation delay between the gNB and the satellite.
  • the UE acquires its own position using GNSS measurements and the UE obtains the satellite position using satellite orbital data (including satellite position at a certain time) broadcast by the network.
  • the pre-compensation TA is then twice the sum of the propagation delay on the feeder link and the propagation delay between the satellite and the UE.
  • the gNB broadcasts a timestamp (in SIB9), which the UE compares with a reference timestamp acquired from GNSS. Based on the difference between these two timestamps, the UE can calculate the propagation delay between the gNB and the UE, and the pre-compensation TA is twice as long as this propagation delay.
  • the gNB provides the UE with an accurate (i.e., fine-adjusted) TA in the Random Access Response message (in 4-step RA) or MsgB (in 2-step RA), based on the time of reception of the random access preamble.
  • the gNB can subsequently adjust the UE’s TA using a Timing Advance Command MAC CE (or an Absolute Timing Advance Command MAC CE), based on the timing of receptions of uplink transmissions from the UE.
  • a goal of such network control of the UE timing advance is typically to keep the time error of the UE uplink transmissions at the gNB’ s receiver within the cyclic prefix (which is required for correct decoding of the uplink transmissions).
  • the time advance control framework also includes a time alignment timer that the gNB configures the UE with.
  • the time alignment timer is restarted every time the gNB adjusts the UE’ s TA and if the time alignment timer expires, the UE is not allowed to transmit in the uplink without a prior random access procedure (which serves the purpose to provide the UE with a valid timing advance).
  • 3GPP has also agreed that in addition to the gNB’s control of the UE’s TA, the UE is allowed to autonomously update its TA based on estimation of changes in the UE-gNB RTT using the UE’s location (e.g., obtained from GNSS measurement) and knowledge of the serving satellite’s ephemeris data and feeder link delay information from the gNB.
  • the UE is allowed to autonomously update its TA based on estimation of changes in the UE-gNB RTT using the UE’s location (e.g., obtained from GNSS measurement) and knowledge of the serving satellite’s ephemeris data and feeder link delay information from the gNB.
  • a second relevant aspect is that not only is the propagation delay between the UE and a satellite, or between the UE and a gNB, very long in NTN, but due to the large distances, the difference in propagation delay to two different satellites, or two different gNBs, may be significant on the timescales relevant for cellular communication, including signaling procedures, even when the satellites/gNBs serve neighboring cells. This has an impact on all procedures involving reception or transmission in two cells served by different satellites and/or different gNBs.
  • a third important aspect related to the long propagation delay/RTT in non-terrestrial networks is the introduction of an additional parameter to compensate for the long propagation delay/RTT.
  • the UE-gNB RTT may range from more or less zero to several tens of microseconds in a cell.
  • a major difference in non-terrestrial networks, apart from the sheer size of the propagation delay/RTT, is that even at the location in the cell where the propagation delay/RTT is the smallest, it will be large and nowhere close to zero. In fact, the variation of the propagation delay/RTT within a NTN cell is small compared to the propagation delay/RTT.
  • Koffset (or sometimes K offset).
  • Koffset may potentially be used in various timing related mechanisms, but the main application is to use it in the scheduling of uplink transmissions on the physical uplink shared channel (PUSCH).
  • Koffset is used to indicate an additional delay between the uplink grant and the PUSCH transmission resources allocated by uplink grant to be added to the slot offset parameter K2 in the DCI containing the uplink grant.
  • the offset between the uplink grant and the slot in which the PUSCH transmission resources are allocated is thus Koffset + K2.
  • Koffset ensures that the UE is never scheduled to transmit at a point in time that, due to the large TA the UE has to apply, would occur before the point in time when the UE receives the uplink grant.
  • 3 GPP has considered letting the network’s configuration of Koffset account for the TA that the UE has used and may have signaled to the network.
  • a fourth important aspect closely related to the timing is a Doppler frequency offset induced by the motion of the satellite.
  • the access link may be exposed to Doppler shift in the order of 10 - 100 kHz in sub-6 GHz frequency band and proportionally higher in higher frequency bands.
  • the Doppler shift is varying, with a rate of up to several hundred Hz per second in the S-band and several kHz per second in the Ka-band.
  • TR 38.821 specifies that ephemeris data may be provided to the UE, for example, to assist with pointing a directional antenna (or an antenna beam) towards the satellite, and to calculate a correct timing advance and Doppler shift. Broadcasting of ephemeris data in the system information is one option.
  • a satellite orbit can be fully described using six parameters. Which set of parameters is chosen can be decided by the user; many different representations are possible. For example, a choice of parameters used often in astronomy is the set (a, a, i, Q, co, t).
  • the semi-major axis a and the eccentricity a describe the shape and size of the orbit ellipse; the inclination i, the right ascension of the ascending node Q, and the argument of periapsis co determine its position in space, and the epoch t determines a reference time (e.g., the time when the satellite moves through periapsis).
  • This set of parameters is illustrated in FIGURE 2.
  • the two line elements use mean motion n and mean anomaly M instead of a and t.
  • a different set of parameters is the position and velocity vector (x, y, z, v x , v y , v z ) of a satellite. These are sometimes referred to as orbital state vectors. They can be derived from the orbital elements and vice versa, because the information they contain is equivalent. All these formulations (and many others) are possible choices for the format of ephemeris data to be used in NTN.
  • Set 1 includes satellite position and velocity state vectors (e.g., position X,Y,Z in ECEF (m) and velocity VX,VY,VZ in ECEF (m/s)).
  • Set 2 includes at least the following parameters in orbital parameter ephemeris format: semi-major axis a [m], eccentricity e, argument of periapsis co [rad], longitude of ascending node [rad], inclination i [rad], and mean anomaly M [rad] at epoch time to. Specifications may support delivery of ephemeris information using both ephemeris formats, i.e., state vectors and orbital elements.
  • a validity timer for uplink synchronization (e.g., for satellite ephemeris and potentially other aspects) configured by the network is recommended.
  • the coverage pattern of NTN is described in section 4.6 of 3GPP TR 38.811 as follows. Satellite or aerial vehicles typically generate several beams over a given area. The footprint of the beams are typically an elliptic shape. The beam footprint may move over the earth with the satellite or the aerial vehicle motion on its orbit. Alternatively, the beam footprint may be earth fixed, in such case a beam pointing mechanism (mechanical or electronic steering feature) compensates for the satellite or the aerial vehicle motion.
  • FIGURE 3 illustrates typical beam patterns of various NTN access networks
  • NTNs include one or several sat-gateways that connect the NTN to a public data network.
  • a GEO satellite is fed by one or several sat- gateways that are deployed across the satellite targeted coverage (e.g., regional or even continental coverage).
  • UE in a cell are served by only one sat-gateway.
  • a non-GEO satellite is served successively by one sat-gateway at a time. The system ensures service and feeder link continuity between the successive serving sat-gateways with sufficient time duration to proceed with mobility anchoring and hand-over.
  • Each satellite has the capability to steer beams towards fixed points on earth using beamforming techniques. This is applicable for a period of time corresponding to the visibility time of the satellite.
  • Max delay variation within a beam is calculated based on Min Elevation angle for both gateway and user equipment.
  • Max differential delay within a beam is calculated based on Max beam footprint diameter at nadir.
  • scenario D which is LEO with regenerative payload
  • scenario D both earth-fixed and earth moving beams have been listed. Factoring in the fixed/non-fixed beams results in an additional scenario.
  • 3GPP TR 38.821 The complete list of 5 scenarios in 3GPP TR 38.821 is then:
  • a UE is assumed to acquire a satellite’s position/velocity/trajectory information from the satellite’s ephemeris data broadcast by the network. The UE can then use this data for various tasks such as calculating time and frequency pre-compensation values.
  • the ephemeris data remains valid for a certain period of time and then needs to be refreshed. Without a mechanism to maintain valid ephemeris data, an NTN system cannot operate efficiently.
  • NTNs non-terrestrial networks
  • Certain aspects of the present disclosure and their embodiments may provide solutions to these or other challenges.
  • Particular embodiments ensure that a user equipment (UE) has sufficiently accurate ephemeris data to enable proper NTN operation.
  • Particular embodiments also define UE and network behavior when the ephemeris data is valid or invalid.
  • task-based or group-based validity timers ensure validity of ephemeris data.
  • Particular embodiments include methods to determine the validity of ephemeris data at the UE/network.
  • Particular embodiments define UE and network behavior with regards to the validity of ephemeris data.
  • a method is performed by a wireless device capable of operating in a NTN.
  • the method comprises: obtaining (e.g., from a network node via broadcast system information or via direct signaling, such as radio resource control (RRC) or medium access control (MAC) signaling) ephemeris data for one or more satellites; obtaining (e.g., from a network node via broadcast system information or via direct signaling, such as RRC or MAC signaling) one or more ephemeris data validity indicators for the ephemeris data for the one or more satellites; determining whether the ephemeris data for the one or more satellites is valid based on the one or more ephemeris validity indicators; and upon determining the ephemeris data for the one or more satellites is not valid, refreshing (e.g., updating, requesting, re-acquiring, etc.) the ephemeris data for the one or more satellites.
  • RRC radio resource control
  • MAC medium access control
  • the method further comprises, upon determining ephemeris data for the one or more satellites is valid, performing a network operation (e.g., uplink synchronization, synchronization signal block (SSB) measurement, etc.) based on the ephemeris data for the one or more satellites.
  • a network operation e.g., uplink synchronization, synchronization signal block (SSB) measurement, etc.
  • the one or more ephemeris data validity indicators comprise a first validity indicator associated with a first operation (e.g., uplink synchronization) to be performed by the wireless device and a second validity indicator associated with a second operation (e.g., SSB measurement) to be performed by the wireless device.
  • a first validity indicator associated with a first operation e.g., uplink synchronization
  • a second validity indicator associated with a second operation e.g., SSB measurement
  • the one or more ephemeris data validity indicators comprise a first validity indicator associated with a first frequency range (e.g., low frequency range) associated with the one or more satellites and a second validity indicator associated with a second frequency range (e.g., high frequency range) associated with the one or more satellites.
  • the one or more ephemeris data validity indicators are associated with at least one of satellite position, satellite speed, and satellite movement direction.
  • the one or more ephemeris data validity indicators comprise a timer value or an absolute time value.
  • the one or more ephemeris data validity indicators are based on a timing advance timer.
  • the method comprises performing a random access procedure.
  • performing a cell selection or reselection is based on the one or more ephemeris data validity indicators.
  • a wireless device comprises processing circuitry operable to perform any of the methods of the wireless device described above.
  • a computer program product comprising a non-transitory computer readable medium storing computer readable program code, the computer readable program code operable, when executed by processing circuitry to perform any of the methods performed by the wireless device described above.
  • a method is performed by a network node capable of operating in an NTN.
  • the method comprises determining one or more ephemeris data validity indicators for ephemeris data associated with one or more satellites and transmitting the one or more ephemeris data validity indicators to a wireless device.
  • a network node comprises processing circuitry operable to perform any of the network node methods described above.
  • Another computer program product comprises a non-transitory computer readable medium storing computer readable program code, the computer readable program code operable, when executed by processing circuitry to perform any of the methods performed by the network node described above.
  • Certain embodiments may provide one or more of the following technical advantages. For example, particular embodiments determine ephemeris validity, and the details of network actions and UE behaviors with respect to ephemeris validity, which are essential for efficient NTN operation. BRIEF DESCRIPTION OF THE DRAWINGS
  • FIGURE 1 is a network diagram illustrating an example architecture of a satellite network with bent pipe transponders
  • FIGURE 2 illustrates orbital elements for describing a satellite orbit
  • FIGURE 3 illustrates typical beam patterns of various non-terrestrial network (NTN) access networks
  • FIGURE 4 illustrates the high-level measurement model
  • FIGURE 5 is a block diagram illustrating an example wireless network
  • FIGURE 6 illustrates an example user equipment, according to certain embodiments.
  • FIGURE 7 is flowchart illustrating an example method in a wireless device, according to certain embodiments.
  • FIGURE 8 is a flowchart illustrating an example method in a network node, according to certain embodiments.
  • FIGURE 9 illustrates a schematic block diagram of a wireless device and network node in a wireless network, according to certain embodiments.
  • FIGURE 10 illustrates an example virtualization environment, according to certain embodiments.
  • FIGURE 11 illustrates an example telecommunication network connected via an intermediate network to a host computer, according to certain embodiments
  • FIGURE 12 illustrates an example host computer communicating via a base station with a user equipment over a partially wireless connection, according to certain embodiments
  • FIGURE 13 is a flowchart illustrating a method implemented, according to certain embodiments.
  • FIGURE 14 is a flowchart illustrating a method implemented in a communication system, according to certain embodiments.
  • FIGURE 15 is a flowchart illustrating a method implemented in a communication system, according to certain embodiments.
  • FIGURE 16 is a flowchart illustrating a method implemented in a communication system, according to certain embodiments.
  • NTNs non-terrestrial networks
  • Certain aspects of the present disclosure and their embodiments may provide solutions to these or other challenges.
  • Particular embodiments ensure that a user equipment (UE) has sufficiently accurate ephemeris data to enable proper NTN operation.
  • Particular embodiments also define UE and network behavior when the ephemeris data is valid or invalid.
  • Particular embodiments define a validity timer or validity duration to ensure that uplink synchronization remains valid.
  • a timer or duration defined for satellite ephemeris data.
  • particular examples include ephemeris data, the examples and embodiments herein are applicable to other validity timers or validity durations.
  • an ephemeris validity timer refers to a timer with which the ephemeris data is assumed to be valid at least when the timer is running.
  • the TAT timeAlignmentTimef refers to the timing advance (TA) timer specified in 38.321 : when this timer is running, the TAC (timing advance command) received from the network is assumed to be valid.
  • a validity timer is defined for each satellite’s ephemeris data.
  • one or more validity timers or validity periods are defined for a satellite’s ephemeris data depending on the purpose for which the ephemeris data is to be used.
  • a timer T1 runs for a satellite’s ephemeris data when it is to be used for uplink synchronization while a timer T2 runs for the same satellite’s ephemeris data when it is to be used to assist synchronization signal block (SSB) measurement for fast random access resource selection, cell selection procedures, etc.
  • SSB synchronization signal block
  • a longer T2 timer, compared to T1 timer, may be enough as the requirement of accuracy of satellite position is lower for SSB measurement than for TA compensation calculation.
  • timer T2 may be started when timer T1 expires, or vice versa.
  • the two timers may exist simultaneously if the UE is not aware of which task (SSB measurement/initial access/gradual TA compensation update) will come first after the UE acquires the ephemeris data, or if the UE is designed such that it does not assess which task may come first.
  • only one of the two timers exists if the UE makes assessment of which timer shall be used.
  • L timers where L is greater than 1 may be employed.
  • a set of timers for each cell group frequency are defined that are valid for the same satellite. This facilitates better control of the synchronization, because the synchronization accuracy requirement may be tighter at higher frequencies, i.e., a much more accurate ephemeris may be needed to meet the synchronization requirement at one frequency as compared to another frequency. This may facilitate carrier aggregation and/or dual connectivity operation.
  • the UE runs only one validity timer for a certain satellite’s ephemeris data but different validity conditions are defined (i.e., UE behavior is specified) depending on the purpose for which the ephemeris data is to be used.
  • the UE needs to perform uplink precompensation, it needs to refresh the ephemeris data if it is invalid, Similarly, if it needs to perform cell selection, it needs to refresh the ephemeris data if it is invalid.
  • the validity conditions are different for the two cases.
  • validity condition there can be up to K validity conditions for the timer.
  • K 2 validity conditions.
  • One embodiment of the validity condition is to compare the timer value with a threshold, but other or additional validity conditions can also be defined (as described elsewhere herein).
  • the validity condition may be different for different cells at different frequencies. This means that while the primary serving cell has one validity condition, the secondary serving cell(s) (operating at a higher carrier frequency) has a different validity condition.
  • a benefit of this is that carrier aggregation or dual connectivity is possible because the validity time may need to be different for different frequencies (and thus cells).
  • a validity timer or validity condition is defined for each group of satellites’ ephemeris data.
  • a first group consists of the serving satellite
  • a second group consists of the neighboring satellites that UE may measure
  • a third group of consists of the rest of the satellites in the constellation.
  • a first, second, and third validity timer are configured for the three groups of satellites, respectively.
  • only a first and a second validity timer are configured for the respective first and the second group of satellites.
  • the above hierarchical division of satellites can also be extended to more than three levels, for example, by considering other satellite characteristics such as elevation angle.
  • the network signals a (absolute) validity time or duration, which is a time instance either defined in terms of slots or subframes or UTC which determines the time the ephemeris data remains valid.
  • a validity time or duration is a time instance either defined in terms of slots or subframes or UTC which determines the time the ephemeris data remains valid.
  • This facilitates better precision compared to the timer, because the time when the UE receives a certain ephemeris data can differ according to when the ephemeris is received, causing timers to run differently at different UEs. Indicating a cell or global definite time when the ephemeris is valid enables better synchronization of the whole network.
  • the “validity timer” duration can be considered to be the duration from the current point until the signaled absolute time. That is, the timer is considered expired if the signaled absolute time is reached regardless of the timer value.
  • the network configures the parameters related to each satellite’s validity timer.
  • This configuration can be broadcast via SI and/or via RRC configuration, e.g., using dedicated radio resource control (RRC) signaling, and/or via media access control (MAC) signaling, e.g., using a new MAC Control Element.
  • RRC radio resource control
  • MAC media access control
  • the network broadcasts generic parameters in the system information (SI) related to validity timer(s) for one or more satellites visible to or relevant for the UEs in a certain cell.
  • SI system information
  • the network may send refined information to the UEs in connected mode, e.g., using dedicated RRC or MAC signaling.
  • the UE resets a validity timer when the UE reacquires the ephemeris data.
  • the UE checks whether the ephemeris data received from the network is the same as the version of the ephemeris data that the UE currently holds. If they are different, the UE resets the validity timer; otherwise, the UE does not reset the validity timer.
  • Another approach is to avoid UE fetching the same ephemeris data after the validity timer expires.
  • the approach is that the satellite updates ephemeris data frequently such that the ephemeris update interval is smaller than the minimal validity timer plus minimal propagation delay plus processing delay.
  • the UE does not need to verify whether ephemeris is the same or not.
  • timer T2 when the UE checks whether ephemeris is the same or not, timer T2 will be reset before its own expiry if UE successfully updates the ephemeris data associated to the expiry of timer Tl. If UE fails to reacquire updated ephemeris data, UE will continue to monitor and try to reacquire the updated/diff erent ephemeris data. If the task associated with timer Tl (requiring higher accuracy of ephemeris data) is triggered after Tl and updated ephemeris data has not been acquired, the UE may send a notification to gNB to ask for prioritized ephemeris updating. In this example, the gNB may have sparse ephemeris data update and leave it upon request, thus, the gNB may reduce unnecessary ephemeris updates.
  • the ephemeris validity timer is greater than or equal to the TAT.
  • RRC e.g., in SIB1
  • multiple time offset values may be configured for different use cases.
  • the TAT is assumed to be expired and should be reset when the ephemeris validity timer expires and is reset.
  • a random access for uplink synchronization may be triggered with a physical random access channel (PRACH) preamble transmitted with the updated timing compensation based on updated ephemeris data. This is needed because the TA calculated based on old precompensation may not be reliable anymore because the precompensation time is updated.
  • PRACH physical random access channel
  • a random access may be needed (i.e., TAT reset may be needed) because the latest TAC is estimated based on uplink transmissions with old TA _pre- compensation. but when the old TA pre-compensation is updated, the current TAC may not be used anymore and a new TA should be estimated instead to ensure uplink timing is aligned with downlink timing at the gNB side.
  • a random access should be triggered to obtain new absolute TA estimation. This may be triggered by either the network or the UE itself.
  • the TAT is assumed to be expired only when the pre-compensation time change is greater than or equal to a time threshold or is out of a certain range of values, which can be either predetermined or a value configured by the network.
  • a predetermined value range can be defined in the following way, and if the pre-compensation time change is not within the range, a new RA is triggered, and the TAT is reset.
  • a 6-bit TAC is used to adjust the uplink timing so that the uplink timing is aligned with downlink timing to some extent.
  • the range of the adjusted values is expressed in following formula, which can be used for this purpose.
  • T r c - - - seconds
  • a. is defined in the following table. 480*10 3 *4096 ° Table 4.2-1 of 3GPP TS38.211 V16.6.0: Supported transmission numerologies.
  • a threshold value can be defined in SIB1 and broadcast to the UEs in the cell so that a UE knows that once the absolute pre-compensation time change is larger than or no less than the threshold, a random access procedure should be triggered and the TAT should be reset when a Timing Advance Command is received in a Random Access Response message for a Serving Cell belonging to a TAG if 4-step RACH is selected or in a MSGB for an SpCell if a 2-step RACH is selected.
  • a random access for uplink synchronization may only be triggered with a PRACH preamble transmitted with the updated timing compensation only when a normal 6 bit TAC cannot adjust the timing shift due to the pre-compensation time change, and in other cases, the 6-bit TAC will be relied on to adjust the uplink transmission time so that the uplink timing and downlink timing at gNB side can be aligned.
  • the UE when the ephemeris validity timer expires, the UE reports to the network when/whether the pre-compensation time change is greater than or equal to a time threshold or is out of a certain range of values.
  • the network can determine whether a new RA should be triggered, or a normal uplink reception can be sufficient to estimate the TA for adjusting the timing in uplink.
  • the information a UE can derive from a satellite’s ephemeris data comprises the satellite’s position, speed (as a scalar value, i.e., the absolute value of the velocity) and movement direction (i.e., the direction of the velocity vector).
  • the satellite position information, the satellite speed information, and the satellite movement direction information are referred to as “components” below.
  • separate validity timers may be configured for the different components. That is, as one example the validity timers may include: one validity timer, Tposition validity, for the satellite position data that the UE can derive from the ephemeris data, one validity timer, T S peed_vaiidity, for the satellite speed data (as a scalar value, i.e., the absolute value of the velocity) that the UE can derive from the ephemeris data, and/or one validity timer, Tdirection validity, for the satellite movement direction data that the UE can derive from the ephemeris data.
  • Tposition validity for the satellite position data that the UE can derive from the ephemeris data
  • T S peed_vaiidity for the satellite speed data (as a scalar value, i.e., the absolute value of the velocity) that the UE can derive from the ephemeris data
  • Tdirection validity for the satellite movement direction data that
  • the time dependence of relevant errors may be indicated, e.g., provided from the network as configuration data, using any of the previously described means.
  • the errors and their respective time dependence may be divided into the above listed components.
  • a UE may be configured with: the time dependence of the satellite position error (e.g., in terms of the 95 th percentile error), the time dependence of the satellite speed error (e.g., in terms of the 95 th percentile error), and/or the time dependence of the satellite movement direction error (e.g., in terms of the 95 th percentile error expressed as an angle relative the satellite’s actual/correct movement direction).
  • the time dependence of the satellite position error e.g., in terms of the 95 th percentile error
  • the time dependence of the satellite speed error e.g., in terms of the 95 th percentile error
  • the time dependence of the satellite movement direction error e.g., in terms of the 95 th percentile error expressed as an angle relative the satellite’s actual/correct movement direction.
  • the time dependence of an error may be expressed as a function of time (i.e., f(t)). This may be a linear function, or a function that also includes higher order terms, such as t 2 terms, t 3 terms, ... t n terms.
  • time dependence functions may be provided for a single (e.g., each) component, where each time dependence function is related to a different error probability, e.g., one function for the 95 th percentile error, one function for the 85 th percentile error and one function for the 75 th percentile error.
  • time dependence information (with time dependence functions for the error of different components, optionally with multiple functions for each component may optionally be combined with conditions, e.g., in terms of error thresholds or error probability thresholds (e.g., a threshold size for the 95 th percentile error of a component), which, when fulfilled (e.g., when a threshold is exceeded) triggers the UE to consider the component information to be invalid.
  • error thresholds or error probability thresholds e.g., a threshold size for the 95 th percentile error of a component
  • Another option is to use a single timer with separate validity conditions for different components (e.g., the satellite’s position information is considered to be invalid when the validity timer has been running for a time period tposition, the satellite’s speed information is considered to be invalid when the validity timer has been running for a time period tspeed, and/or the satellite’s movement direction information is considered to be invalid when the validity timer has been running for a time period tdirection.
  • the satellite’s position information is considered to be invalid when the validity timer has been running for a time period tposition
  • the satellite’s speed information is considered to be invalid when the validity timer has been running for a time period tspeed
  • the satellite’s movement direction information is considered to be invalid when the validity timer has been running for a time period tdirection.
  • different timers may be associated with different error levels (e.g., different levels of the 95 th percentile error) for a single (e.g., each) component.
  • timers associated with overall ephemeris-GNSS (or more straightforwardly satellite-UE) position/speed/direction/Doppler errors can be configured as validity timers.
  • timer/validity condition/validity time value can be configured to the value associated with the allowed largest possible position error (or within a certain gap of such value).
  • Some embodiments include determining ephemeris data validity during connected mode (i.e., RRC CONNECTED state).
  • the UE determines whether the ephemeris data for one or more satellites will remain valid during a connection. This can be determined either prior to accessing the network, or during the connection establishment procedure, or after establishing connection. To this end, the UE needs to know the anticipated connection duration and compare it with the remaining duration until the ephemeris will remain valid.
  • the UE shares information about validity duration of ephemeris data for one or more satellites with the network during connection establishment, and the network indicates to the UE whether its ephemeris data (that is relevant to the connection) is expected to remain valid during the connection.
  • the network determines the expected connection duration and indicates it to the UE.
  • the UE determines whether the ephemeris data for one or more satellites will remain valid during a connection by comparing the validity timer value with the expected connection duration.
  • the connection duration may be determined based on the satellite/UE position information (and/or feeder link delay or gNB-UE propagation delay), resource configuration, number of repetitions, UE power class, bandwidth, number of allocated tones, and the amount of data to be transmitted.
  • connection duration of an eMTC UE may be approximately calculated based on the maximum number of repetitions for its coverage enhancement (CE) mode, the resource configuration information, and satellite/UE position information.
  • CE coverage enhancement
  • a UE in CE mode A can use a maximum of 32 repetitions for data channels whereas that in CE mode B can use a maximum of 2048 repetitions.
  • connection duration of an NB-IoT UE can be approximately calculated based on the number of repetitions that it used for its NPRACH coverage class along with other assistance information described previously.
  • particular embodiments include UE behavior upon validity timer expiry in RRC CONNECTED state. If the validity timer of the serving satellite expires in the RRC connected mode, there are different possibilities for UE behavior.
  • the UE is allowed to complete both uplink transmission and downlink reception.
  • the UE is allowed to complete downlink reception but not uplink transmission unless it reacquires ephemeris data in a measurement gap.
  • the UE is allowed to complete downlink reception. In this case, if the UE would like to initiate uplink transmission, the UE leaves RRC Connected state and enters RRC Idle state to restart the procedure (which includes refreshing the ephemeris data).
  • the UE remains in RRC CONNECTED state, refrains from uplink transmissions and immediately (or as soon as possible) acquires updated ephemeris data for the serving satellite and then resumes normal RRC CONNECTED state operation (i.e., stops refraining from uplink transmissions).
  • the UE performs random access to re-synchronize and re-acquire the ephemeris data. This may, for example, be done by giving the UE a random access preamble to be used only for re-acquiring ephemeris data.
  • the UE may reacquire the ephemeris data after the ongoing transmission/reception completes.
  • the UE is to refresh the invalid satellite ephemeris data in a measurement gap if one is configured by the network.
  • the UE waits a fixed/configured time before reacquiring the ephemeris data. This option works when the event timer accounts for the extra time cost to update ephemeris, so that the UE can enjoy the gain of updating fewer times less important ephemeris data.
  • the incoming (neighbor) satellite data may expire while the serving satellite data is still valid in the connected mode.
  • one or more of the above UE behaviors are specified in the specification.
  • the network indicates to the UE which of the specified UE behaviors is configured. This information may be signaled to the UE in RRC configuration or broadcast in the SI.
  • Some embodiments include network actions. In addition to signaling the validity duration or validity timer as described above, there are a number of actions that the network may perform.
  • the network may choose to perform one or more of the following actions: determine if one or more validity timer(s) may expire during the ongoing connection; indicate to the UE that its validity timer may expire during the ongoing connection; indicate the time instant (e.g., subframe, slot, or symbol) in which the timer may expire; command the UE to refresh its ephemeris data for one or more satellites at or after a certain time instant and/or within a certain time duration after receiving the command from the network; configure measurement gap(s) for the UE if the validity timer may expire during an ongoing connection; indicate the measurement gap configuration to the UE if needed; and/or account for the additional delay due to reacquisition of ephemeris data by the UE before timing out the connection or a radio link failure is declared.
  • the time instant e.g., subframe, slot, or symbol
  • the network may assume that the UE will only be able to transmit in an uplink slot following a period ‘P’ after the slot in which the SIB carrying satellite ephemeris is received by the UE.
  • the pre-specified period P can be specified in the specification or configured by the network and indicated to the UE.
  • the UE may autonomously set the value P and indicate it to the network. It can also be made dependent on the UE category or capability information, etc.
  • Some embodiments include UE behavior upon validity timer expiry in RRC IDLE/RRC INACTIVE state.
  • a UE in RRC IDLE or RRC INACTIVE state acquires new ephemeris when: the validity timer expires; a UE needs to access the cell and the validity timer is expired; a UE needs to access the cell, the validity timer has not expired but the time until the timer expires is shorter than the minimum time required to complete the task which requires valid ephemeris information (e.g., long UL transmission); a UE wakes up from power saving mode; the network sends a command; the network notifies that there is a change/update of the ephemeris information, e.g., through an SI update notification (and optionally with a change of the value tag associated with the SIB in which the changed/updated ephemeris information is included); or the UE needs to perform cell (re-) sei ection and the validity timer is expired.
  • Some embodiments include cell (re)selection based on EVT validity.
  • the ephemeris validity timer status is considered while performing cell (re)selection in addition to the legacy cell selection procedure, e.g., based on RSRP.
  • the main idea is to filter out some cells by checking the EVT and/or other times along with the downlink RSRP quality before performing real cell selection procedure already defined in current specifications.
  • the cells transmitted by that satellite are not considered for cell (re)selection procedure if they are below a certain threshold. This is because the random access may not be successful due to large precompensation error.
  • the UE measures multiple beams (at least one) of a cell and the measurement results (power values) are averaged to derive the cell quality. In doing so, the UE is configured to consider a subset of the detected beams. Filtering takes place at two different levels: at the physical layer to derive beam quality and then at RRC level to derive cell quality from multiple beams. Cell quality from beam measurements is derived in the same way for the serving cell(s) and for the non-serving cell(s).
  • FIGURE 4 illustrates the high-level measurement model.
  • the simple SS-RSRP measurement may be used together with the EVT validation in NTN to determine whether a cell selection should be applied.
  • FIGURE 5 illustrates an example wireless network, according to certain embodiments.
  • the wireless network may comprise and/or interface with any type of communication, telecommunication, data, cellular, and/or radio network or other similar type of system.
  • the wireless network may be configured to operate according to specific standards or other types of predefined rules or procedures.
  • wireless network may implement communication standards, such as Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), and/or other suitable 2G, 3G, 4G, or 5G standards; wireless local area network (WLAN) standards, such as the IEEE 802.11 standards; and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave and/or ZigBee standards.
  • GSM Global System for Mobile Communications
  • UMTS Universal Mobile Telecommunications System
  • LTE Long Term Evolution
  • WLAN wireless local area network
  • WiMax Worldwide Interoperability for Microwave Access
  • Bluetooth Z-Wave and/or ZigBee standards.
  • Network 106 may comprise one or more backhaul networks, core networks, IP networks, public switched telephone networks (PSTNs), packet data networks, optical networks, wide-area networks (WANs), local area networks (LANs), wireless local area networks (WLANs), wired networks, wireless networks, metropolitan area networks, and other networks to enable communication between devices.
  • PSTNs public switched telephone networks
  • WANs wide-area networks
  • LANs local area networks
  • WLANs wireless local area networks
  • wired networks wireless networks, metropolitan area networks, and other networks to enable communication between devices.
  • Network node 160 and WD 110 comprise various components described in more detail below. These components work together to provide network node and/or wireless device functionality, such as providing wireless connections in a wireless network.
  • the wireless network may comprise any number of wired or wireless networks, network nodes, base stations, controllers, wireless devices, relay stations, and/or any other components or systems that may facilitate or participate in the communication of data and/or signals whether via wired or wireless connections.
  • network node refers to equipment capable, configured, arranged and/or operable to communicate directly or indirectly with a wireless device and/or with other network nodes or equipment in the wireless network to enable and/or provide wireless access to the wireless device and/or to perform other functions (e.g., administration) in the wireless network.
  • network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR NodeBs (gNBs)).
  • APs access points
  • BSs base stations
  • Node Bs evolved Node Bs
  • gNBs NR NodeBs
  • Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and may then also be referred to as femto base stations, pico base stations, micro base stations, or macro base stations.
  • a base station may be a relay node or a relay donor node controlling a relay.
  • a network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units and/or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs).
  • RRUs remote radio units
  • RRHs Remote Radio Heads
  • Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio.
  • Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).
  • DAS distributed antenna system
  • network nodes include multi -standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell/multicast coordination entities (MCEs), core network nodes (e.g., MSCs, MMEs), O&M nodes, OSS nodes, SON nodes, positioning nodes (e.g., E-SMLCs), and/or MDTs.
  • MSR multi -standard radio
  • RNCs radio network controllers
  • BSCs base station controllers
  • BTSs base transceiver stations
  • MCEs multi-cell/multicast coordination entities
  • core network nodes e.g., MSCs, MMEs
  • O&M nodes e.g., OSS nodes
  • SON nodes e.g., SON nodes
  • positioning nodes e.g., E-SMLCs
  • a network node may be a virtual network node as described in more detail below. More generally, however, network nodes may represent any suitable device (or group of devices) capable, configured, arranged, and/or operable to enable and/or provide a wireless device with access to the wireless network or to provide some service to a wireless device that has accessed the wireless network.
  • network node 160 includes processing circuitry 170, device readable medium 180, interface 190, auxiliary equipment 184, power source 186, power circuitry 187, and antenna 162.
  • network node 160 illustrated in the example wireless network of FIGURE 5 may represent a device that includes the illustrated combination of hardware components, other embodiments may comprise network nodes with different combinations of components.
  • a network node comprises any suitable combination of hardware and/or software needed to perform the tasks, features, functions and methods disclosed herein.
  • components of network node 160 are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, a network node may comprise multiple different physical components that make up a single illustrated component (e.g., device readable medium 180 may comprise multiple separate hard drives as well as multiple RAM modules).
  • network node 160 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components.
  • network node 160 comprises multiple separate components (e.g., BTS and BSC components)
  • one or more of the separate components may be shared among several network nodes.
  • a single RNC may control multiple NodeB ’s.
  • each unique NodeB and RNC pair may in some instances be considered a single separate network node.
  • network node 160 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate device readable medium 180 for the different RATs) and some components may be reused (e.g., the same antenna 162 may be shared by the RATs).
  • Network node 160 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 160, such as, for example, GSM, WCDMA, LTE, NR, WiFi, or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 160.
  • Processing circuitry 170 is configured to perform any determining, calculating, or similar operations (e.g., certain obtaining operations) described herein as being provided by a network node. These operations performed by processing circuitry 170 may include processing information obtained by processing circuitry 170 by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination.
  • processing information obtained by processing circuitry 170 by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination.
  • Processing circuitry 170 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and/or encoded logic operable to provide, either alone or in conjunction with other network node 160 components, such as device readable medium 180, network node 160 functionality.
  • processing circuitry 170 may execute instructions stored in device readable medium 180 or in memory within processing circuitry 170. Such functionality may include providing any of the various wireless features, functions, or benefits discussed herein.
  • processing circuitry 170 may include a system on a chip (SOC).
  • processing circuitry 170 may include one or more of radio frequency (RF) transceiver circuitry 172 and baseband processing circuitry 174.
  • radio frequency (RF) transceiver circuitry 172 and baseband processing circuitry 174 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units.
  • part or all of RF transceiver circuitry 172 and baseband processing circuitry 174 may be on the same chip or set of chips, boards, or units
  • processing circuitry 170 executing instructions stored on device readable medium 180 or memory within processing circuitry 170.
  • some or all of the functionality may be provided by processing circuitry 170 without executing instructions stored on a separate or discrete device readable medium, such as in a hard-wired manner.
  • processing circuitry 170 can be configured to perform the described functionality.
  • Device readable medium 180 may comprise any form of volatile or non-volatile computer readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device readable and/or computer-executable memory devices that store information, data, and/or instructions that may be used by processing circuitry 170.
  • volatile or non-volatile computer readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non
  • Device readable medium 180 may store any suitable instructions, data or information, including a computer program, software, an application including one or more of logic, rules, code, tables, etc. and/or other instructions capable of being executed by processing circuitry 170 and, utilized by network node 160.
  • Device readable medium 180 may be used to store any calculations made by processing circuitry 170 and/or any data received via interface 190.
  • processing circuitry 170 and device readable medium 180 may be considered to be integrated.
  • Interface 190 is used in the wired or wireless communication of signaling and/or data between network node 160, network 106, and/or WDs 110. As illustrated, interface 190 comprises port(s)/terminal(s) 194 to send and receive data, for example to and from network 106 over a wired connection. Interface 190 also includes radio front end circuitry 192 that may be coupled to, or in certain embodiments a part of, antenna 162.
  • Radio front end circuitry 192 comprises filters 198 and amplifiers 196.
  • Radio front end circuitry 192 may be connected to antenna 162 and processing circuitry 170. Radio front end circuitry may be configured to condition signals communicated between antenna 162 and processing circuitry 170.
  • Radio front end circuitry 192 may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry 192 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 198 and/or amplifiers 196. The radio signal may then be transmitted via antenna 162.
  • antenna 162 may collect radio signals which are then converted into digital data by radio front end circuitry 192. The digital data may be passed to processing circuitry 170.
  • the interface may comprise different components and/or different combinations of components.
  • network node 160 may not include separate radio front end circuitry 192, instead, processing circuitry 170 may comprise radio front end circuitry and may be connected to antenna 162 without separate radio front end circuitry 192.
  • processing circuitry 170 may comprise radio front end circuitry and may be connected to antenna 162 without separate radio front end circuitry 192.
  • all or some of RF transceiver circuitry 172 may be considered a part of interface 190.
  • interface 190 may include one or more ports or terminals 194, radio front end circuitry 192, and RF transceiver circuitry 172, as part of a radio unit (not shown), and interface 190 may communicate with baseband processing circuitry 174, which is part of a digital unit (not shown).
  • Antenna 162 may include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. Antenna 162 may be coupled to radio front end circuitry 190 and may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In some embodiments, antenna 162 may comprise one or more omni-directional, sector or panel antennas operable to transmit/receive radio signals between, for example, 2 GHz and 66 GHz. An omni-directional antenna may be used to transmit/receive radio signals in any direction, a sector antenna may be used to transmit/receive radio signals from devices within a particular area, and a panel antenna may be a line of sight antenna used to transmit/receive radio signals in a relatively straight line. In some instances, the use of more than one antenna may be referred to as MIMO. In certain embodiments, antenna 162 may be separate from network node 160 and may be connectable to network node 160 through an interface or port.
  • Antenna 162, interface 190, and/or processing circuitry 170 may be configured to perform any receiving operations and/or certain obtaining operations described herein as being performed by a network node. Any information, data and/or signals may be received from a wireless device, another network node and/or any other network equipment. Similarly, antenna 162, interface 190, and/or processing circuitry 170 may be configured to perform any transmitting operations described herein as being performed by a network node. Any information, data and/or signals may be transmitted to a wireless device, another network node and/or any other network equipment.
  • Power circuitry 187 may comprise, or be coupled to, power management circuitry and is configured to supply the components of network node 160 with power for performing the functionality described herein. Power circuitry 187 may receive power from power source 186. Power source 186 and/or power circuitry 187 may be configured to provide power to the various components of network node 160 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). Power source 186 may either be included in, or external to, power circuitry 187 and/or network node 160.
  • network node 160 may be connectable to an external power source (e.g., an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry 187.
  • power source 186 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry 187. The battery may provide backup power should the external power source fail.
  • Other types of power sources such as photovoltaic devices, may also be used.
  • network node 160 may include additional components beyond those shown in FIGURE 5 that may be responsible for providing certain aspects of the network node’s functionality, including any of the functionality described herein and/or any functionality necessary to support the subject matter described herein.
  • network node 160 may include user interface equipment to allow input of information into network node 160 and to allow output of information from network node 160. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for network node 160.
  • wireless device refers to a device capable, configured, arranged and/or operable to communicate wirelessly with network nodes and/or other wireless devices. Unless otherwise noted, the term WD may be used interchangeably herein with user equipment (UE). Communicating wirelessly may involve transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information through air.
  • a WD may be configured to transmit and/or receive information without direct human interaction.
  • a WD may be designed to transmit information to a network on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the network.
  • Examples of a WD include, but are not limited to, a smart phone, a mobile phone, a cell phone, a voice over IP (VoIP) phone, a wireless local loop phone, a desktop computer, a personal digital assistant (PDA), a wireless cameras, a gaming console or device, a music storage device, a playback appliance, a wearable terminal device, a wireless endpoint, a mobile station, a tablet, a laptop, a laptop-embedded equipment (LEE), a laptop-mounted equipment (LME), a smart device, a wireless customer-premise equipment (CPE), a vehicle-mounted wireless terminal device, etc.
  • VoIP voice over IP
  • PDA personal digital assistant
  • LOE laptop-embedded equipment
  • LME laptop-mounted equipment
  • CPE wireless customer-premise equipment
  • a WD may support device-to-device (D2D) communication, for example by implementing a 3 GPP standard for sidelink communication, vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-everything (V2X) and may in this case be referred to as a D2D communication device.
  • D2D device-to-device
  • a WD may represent a machine or other device that performs monitoring and/or measurements and transmits the results of such monitoring and/or measurements to another WD and/or a network node.
  • the WD may in this case be a machine-to-machine (M2M) device, which may in a 3 GPP context be referred to as an MTC device.
  • M2M machine-to-machine
  • the WD may be a UE implementing the 3 GPP narrow band internet of things (NB-IoT) standard.
  • NB-IoT narrow band internet of things
  • machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances (e.g., refrigerators, televisions, etc.) personal wearables (e.g., watches, fitness trackers, etc.).
  • a WD may represent a vehicle or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation.
  • a WD as described above may represent the endpoint of a wireless connection, in which case the device may be referred to as a wireless terminal.
  • a WD as described above may be mobile, in which case it may also be referred to as a mobile device or a mobile terminal.
  • wireless device 110 includes antenna 111, interface 114, processing circuitry 120, device readable medium 130, user interface equipment 132, auxiliary equipment 134, power source 136 and power circuitry 137.
  • WD 110 may include multiple sets of one or more of the illustrated components for different wireless technologies supported by WD 110, such as, for example, GSM, WCDMA, LTE, NR, WiFi, WiMAX, or Bluetooth wireless technologies, just to mention a few. These wireless technologies may be integrated into the same or different chips or set of chips as other components within WD 110.
  • Antenna 111 may include one or more antennas or antenna arrays, configured to send and/or receive wireless signals, and is connected to interface 114. In certain alternative embodiments, antenna 111 may be separate from WD 110 and be connectable to WD 110 through an interface or port. Antenna 111, interface 114, and/or processing circuitry 120 may be configured to perform any receiving or transmitting operations described herein as being performed by a WD. Any information, data and/or signals may be received from a network node and/or another WD. In some embodiments, radio front end circuitry and/or antenna 111 may be considered an interface.
  • interface 114 comprises radio front end circuitry 112 and antenna 111.
  • Radio front end circuitry 112 comprise one or more filters 118 and amplifiers 116.
  • Radio front end circuitry 114 is connected to antenna 111 and processing circuitry 120 and is configured to condition signals communicated between antenna 111 and processing circuitry 120.
  • Radio front end circuitry 112 may be coupled to or a part of antenna 111.
  • WD 110 may not include separate radio front end circuitry 112; rather, processing circuitry 120 may comprise radio front end circuitry and may be connected to antenna 111.
  • some or all of RF transceiver circuitry 122 may be considered a part of interface 114.
  • Radio front end circuitry 112 may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry 112 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 118 and/or amplifiers 116. The radio signal may then be transmitted via antenna 111. Similarly, when receiving data, antenna 111 may collect radio signals which are then converted into digital data by radio front end circuitry 112. The digital data may be passed to processing circuitry 120. In other embodiments, the interface may comprise different components and/or different combinations of components.
  • Processing circuitry 120 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software, and/or encoded logic operable to provide, either alone or in conjunction with other WD 110 components, such as device readable medium 130, WD 110 functionality. Such functionality may include providing any of the various wireless features or benefits discussed herein. For example, processing circuitry 120 may execute instructions stored in device readable medium 130 or in memory within processing circuitry 120 to provide the functionality disclosed herein.
  • processing circuitry 120 includes one or more of RF transceiver circuitry 122, baseband processing circuitry 124, and application processing circuitry 126.
  • the processing circuitry may comprise different components and/or different combinations of components.
  • processing circuitry 120 of WD 110 may comprise a SOC.
  • RF transceiver circuitry 122, baseband processing circuitry 124, and application processing circuitry 126 may be on separate chips or sets of chips.
  • part or all of baseband processing circuitry 124 and application processing circuitry 126 may be combined into one chip or set of chips, and RF transceiver circuitry 122 may be on a separate chip or set of chips.
  • part or all of RF transceiver circuitry 122 and baseband processing circuitry 124 may be on the same chip or set of chips, and application processing circuitry 126 may be on a separate chip or set of chips.
  • part or all of RF transceiver circuitry 122, baseband processing circuitry 124, and application processing circuitry 126 may be combined in the same chip or set of chips.
  • RF transceiver circuitry 122 may be a part of interface 114.
  • RF transceiver circuitry 122 may condition RF signals for processing circuitry 120.
  • processing circuitry 120 executing instructions stored on device readable medium 130, which in certain embodiments may be a computer-readable storage medium.
  • some or all of the functionality may be provided by processing circuitry 120 without executing instructions stored on a separate or discrete device readable storage medium, such as in a hard-wired manner.
  • processing circuitry 120 can be configured to perform the described functionality. The benefits provided by such functionality are not limited to processing circuitry 120 alone or to other components of WD 110, but are enjoyed by WD 110, and/or by end users and the wireless network generally.
  • Processing circuitry 120 may be configured to perform any determining, calculating, or similar operations (e.g., certain obtaining operations) described herein as being performed by a WD. These operations, as performed by processing circuitry 120, may include processing information obtained by processing circuitry 120 by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored by WD 110, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination.
  • processing information obtained by processing circuitry 120 by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored by WD 110, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination.
  • Device readable medium 130 may be operable to store a computer program, software, an application including one or more of logic, rules, code, tables, etc. and/or other instructions capable of being executed by processing circuitry 120.
  • Device readable medium 130 may include computer memory (e.g., Random Access Memory (RAM) or Read Only Memory (ROM)), mass storage media (e.g., a hard disk), removable storage media (e.g., a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non- transitory device readable and/or computer executable memory devices that store information, data, and/or instructions that may be used by processing circuitry 120.
  • processing circuitry 120 and device readable medium 130 may be integrated.
  • User interface equipment 132 may provide components that allow for a human user to interact with WD 110. Such interaction may be of many forms, such as visual, audial, tactile, etc. User interface equipment 132 may be operable to produce output to the user and to allow the user to provide input to WD 110. The type of interaction may vary depending on the type of user interface equipment 132 installed in WD 110. For example, if WD 110 is a smart phone, the interaction may be via a touch screen; if WD 110 is a smart meter, the interaction may be through a screen that provides usage (e.g., the number of gallons used) or a speaker that provides an audible alert (e.g., if smoke is detected).
  • usage e.g., the number of gallons used
  • a speaker that provides an audible alert
  • User interface equipment 132 may include input interfaces, devices and circuits, and output interfaces, devices and circuits. User interface equipment 132 is configured to allow input of information into WD 110 and is connected to processing circuitry 120 to allow processing circuitry 120 to process the input information. User interface equipment 132 may include, for example, a microphone, a proximity or other sensor, keys/buttons, a touch display, one or more cameras, a USB port, or other input circuitry. User interface equipment 132 is also configured to allow output of information from WD 110, and to allow processing circuitry 120 to output information from WD 110. User interface equipment 132 may include, for example, a speaker, a display, vibrating circuitry, a USB port, a headphone interface, or other output circuitry. Using one or more input and output interfaces, devices, and circuits, of user interface equipment 132, WD 110 may communicate with end users and/or the wireless network and allow them to benefit from the functionality described herein.
  • Auxiliary equipment 134 is operable to provide more specific functionality which may not be generally performed by WDs. This may comprise specialized sensors for doing measurements for various purposes, interfaces for additional types of communication such as wired communications etc. The inclusion and type of components of auxiliary equipment 134 may vary depending on the embodiment and/or scenario.
  • Power source 136 may, in some embodiments, be in the form of a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic devices or power cells, may also be used.
  • WD 110 may further comprise power circuitry 137 for delivering power from power source 136 to the various parts of WD 110 which need power from power source 136 to carry out any functionality described or indicated herein.
  • Power circuitry 137 may in certain embodiments comprise power management circuitry.
  • Power circuitry 137 may additionally or alternatively be operable to receive power from an external power source; in which case WD 110 may be connectable to the external power source (such as an electricity outlet) via input circuitry or an interface such as an electrical power cable. Power circuitry 137 may also in certain embodiments be operable to deliver power from an external power source to power source 136. This may be, for example, for the charging of power source 136. Power circuitry 137 may perform any formatting, converting, or other modification to the power from power source 136 to make the power suitable for the respective components of WD 110 to which power is supplied.
  • a wireless network such as the example wireless network illustrated in FIGURE 5.
  • the wireless network of FIGURE 5 only depicts network 106, network nodes 160 and 160b, and WDs 110, 110b, and 110c.
  • a wireless network may further include any additional elements suitable to support communication between wireless devices or between a wireless device and another communication device, such as a landline telephone, a service provider, or any other network node or end device.
  • network node 160 and wireless device (WD) 110 are depicted with additional detail.
  • the wireless network may provide communication and other types of services to one or more wireless devices to facilitate the wireless devices’ access to and/or use of the services provided by, or via, the wireless network.
  • FIGURE 6 illustrates an example user equipment, according to certain embodiments.
  • a user equipment or UE may not necessarily have a user in the sense of a human user who owns and/or operates the relevant device.
  • a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller).
  • a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).
  • UE 200 may be any UE identified by the 3 rd Generation Partnership Project (3GPP), including a NB-IoT UE, a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE.
  • UE 200 as illustrated in FIGURE 6, is one example of a WD configured for communication in accordance with one or more communication standards promulgated by the 3 rd Generation Partnership Project (3GPP), such as 3GPP’s GSM, UMTS, LTE, and/or 5G standards.
  • 3GPP 3 rd Generation Partnership Project
  • UE 200 includes processing circuitry 201 that is operatively coupled to input/output interface 205, radio frequency (RF) interface 209, network connection interface 211, memory 215 including random access memory (RAM) 217, read-only memory (ROM) 219, and storage medium 221 or the like, communication subsystem 231, power source 233, and/or any other component, or any combination thereof.
  • Storage medium 221 includes operating system 223, application program 225, and data 227. In other embodiments, storage medium 221 may include other similar types of information.
  • Certain UEs may use all the components shown in FIGURE 6, or only a subset of the components. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.
  • processing circuitry 201 may be configured to process computer instructions and data.
  • Processing circuitry 201 may be configured to implement any sequential state machine operative to execute machine instructions stored as machine-readable computer programs in the memory, such as one or more hardware-implemented state machines (e.g., in discrete logic, FPGA, ASIC, etc.); programmable logic together with appropriate firmware; one or more stored program, general-purpose processors, such as a microprocessor or Digital Signal Processor (DSP), together with appropriate software; or any combination of the above.
  • the processing circuitry 201 may include two central processing units (CPUs). Data may be information in a form suitable for use by a computer.
  • input/output interface 205 may be configured to provide a communication interface to an input device, output device, or input and output device.
  • UE 200 may be configured to use an output device via input/output interface 205.
  • An output device may use the same type of interface port as an input device.
  • a USB port may be used to provide input to and output from UE 200.
  • the output device may be a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof.
  • UE 200 may be configured to use an input device via input/output interface 205 to allow a user to capture information into UE 200.
  • the input device may include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like.
  • the presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user.
  • a sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, another like sensor, or any combination thereof.
  • the input device may be an accelerometer, a magnetometer, a digital camera, a microphone, and an optical sensor.
  • RF interface 209 may be configured to provide a communication interface to RF components such as a transmitter, a receiver, and an antenna.
  • Network connection interface 211 may be configured to provide a communication interface to network 243a.
  • Network 243a may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof.
  • network 243a may comprise a Wi-Fi network.
  • Network connection interface 211 may be configured to include a receiver and a transmitter interface used to communicate with one or more other devices over a communication network according to one or more communication protocols, such as Ethernet, TCP/IP, SONET, ATM, or the like.
  • Network connection interface 211 may implement receiver and transmitter functionality appropriate to the communication network links (e.g., optical, electrical, and the like). The transmitter and receiver functions may share circuit components, software or firmware, or alternatively may be implemented separately.
  • RAM 217 may be configured to interface via bus 202 to processing circuitry 201 to provide storage or caching of data or computer instructions during the execution of software programs such as the operating system, application programs, and device drivers.
  • ROM 219 may be configured to provide computer instructions or data to processing circuitry 201.
  • ROM 219 may be configured to store invariant low-level system code or data for basic system functions such as basic input and output (I/O), startup, or reception of keystrokes from a keyboard that are stored in a non-volatile memory.
  • Storage medium 221 may be configured to include memory such as RAM, ROM, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, floppy disks, hard disks, removable cartridges, or flash drives.
  • storage medium 221 may be configured to include operating system 223, application program 225 such as a web browser application, a widget or gadget engine or another application, and data file 227.
  • Storage medium 221 may store, for use by UE 200, any of a variety of various operating systems or combinations of operating systems.
  • Storage medium 221 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), floppy disk drive, flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external microDIMM SDRAM, smartcard memory such as a subscriber identity module or a removable user identity (SIM/RUIM) module, other memory, or any combination thereof.
  • RAID redundant array of independent disks
  • HD-DVD high-density digital versatile disc
  • HDDS holographic digital data storage
  • DIMM external mini-dual in-line memory module
  • SDRAM synchronous dynamic random access memory
  • SIM/RUIM removable user identity
  • Storage medium 221 may allow UE 200 to access computer-executable instructions, application programs or the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data.
  • An article of manufacture, such as one utilizing a communication system may be tangibly embodied in storage medium 221, which may comprise a device readable medium.
  • processing circuitry 201 may be configured to communicate with network 243b using communication subsystem 231.
  • Network 243a and network 243b may be the same network or networks or different network or networks.
  • Communication subsystem 231 may be configured to include one or more transceivers used to communicate with network 243b.
  • communication subsystem 231 may be configured to include one or more transceivers used to communicate with one or more remote transceivers of another device capable of wireless communication such as another WD, UE, or base station of a radio access network (RAN) according to one or more communication protocols, such as IEEE 802.2, CDMA, WCDMA, GSM, LTE, UTRAN, WiMax, or the like.
  • RAN radio access network
  • Each transceiver may include transmitter 233 and/or receiver 235 to implement transmitter or receiver functionality, respectively, appropriate to the RAN links (e.g., frequency allocations and the like). Further, transmitter 233 and receiver 235 of each transceiver may share circuit components, software or firmware, or alternatively may be implemented separately.
  • the communication functions of communication subsystem 231 may include data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof.
  • communication subsystem 231 may include cellular communication, Wi-Fi communication, Bluetooth communication, and GPS communication.
  • Network 243b may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof.
  • network 243b may be a cellular network, a Wi-Fi network, and/or a near-field network.
  • Power source 213 may be configured to provide alternating current (AC) or direct current (DC) power to components of UE 200.
  • communication subsystem 231 may be configured to include any of the components described herein.
  • processing circuitry 201 may be configured to communicate with any of such components over bus 202.
  • any of such components may be represented by program instructions stored in memory that when executed by processing circuitry 201 perform the corresponding functions described herein.
  • the functionality of any of such components may be partitioned between processing circuitry 201 and communication subsystem 231.
  • the non-computationally intensive functions of any of such components may be implemented in software or firmware and the computationally intensive functions may be implemented in hardware.
  • FIGURE 7 is a flowchart illustrating an example method in a wireless device, according to certain embodiments. In particular embodiments, one or more steps of FIGURE 7 may be performed by wireless device 110 described with respect to FIGURE 5. The wireless device is capable of operating in an NTN.
  • the method begins at step 712, where the wireless device (e.g., wireless device 110) obtains (e.g., from a network node via broadcast system information or via direct signaling, such as radio resource control (RRC) signaling) ephemeris data for one or more satellites. More examples of obtaining ephemeris data are described in TR 38.821.
  • the ephemeris data may include position and velocity state vectors, orbital elements, etc.
  • the ephemeris data may comprise any of the ephemeris data described in the embodiments and examples above.
  • the wireless device obtains (e.g., from a network node via broadcast system information or via direct signaling, such as RRC signaling) one or more ephemeris data validity indicators for the ephemeris data for the one or more satellites. For example, predictions of satellite positions in general degrade with increasing age of the ephemeris data used, due to atmospheric drag, maneuvering of the satellite, imperfections in the orbital models used, etc. Thus, an ephemeris data validity indicator indicates for how long the associated ephemeris data is valid for performing particular operations.
  • An ephemeris data validity indicator may comprise a timer, and absolute time, or any other validity indicator described in the embodiments and examples above.
  • the one or more ephemeris data validity indicators comprise a first validity indicator associated with a first operation (e.g., uplink synchronization) to be performed by the wireless device and a second validity indicator associated with a second operation (e.g., SSB measurement) to be performed by the wireless device.
  • a first validity indicator associated with a first operation e.g., uplink synchronization
  • a second validity indicator associated with a second operation e.g., SSB measurement
  • a timer T1 runs for a satellite’s ephemeris data when it is to be used for uplink synchronization while a timer T2 runs for the same satellite’s ephemeris data when it is to be used to assist SSB measurement for fast random access resource selection, cell selection procedures, etc.
  • a longer T2 timer, compared to T1 timer may be enough because the requirement of accuracy of satellite position is lower for SSB measurement than for TA compensation calculation.
  • the one or more ephemeris data validity indicators comprise a first validity indicator associated with a first frequency range (e.g., low frequency range may need less accurate ephemeris data) associated with the one or more satellites and a second validity indicator associated with a second frequency range (e.g., high frequency range may need more accurate ephemeris data) associated with the one or more satellites.
  • a first validity indicator associated with a first frequency range e.g., low frequency range may need less accurate ephemeris data
  • a second validity indicator associated with a second frequency range e.g., high frequency range may need more accurate ephemeris data
  • different validity indicators may be associated with a cell type (e.g., serving cell, primary cell, secondary cell, etc.).
  • a cell type e.g., serving cell, primary cell, secondary cell, etc.
  • the one or more ephemeris data validity indicators are associated with at least one of satellite position, satellite speed, and satellite movement direction.
  • different types of ephemeris data may be associated with different thresholds for validity.
  • the one or more ephemeris data validity indicators are based on a timing advance timer.
  • the ephemeris data validity indicator may comprise a scaling factor and/or an offset applied to a timing advance timer according to any of the embodiments and examples described herein.
  • the wireless device determining whether the ephemeris data for the one or more satellites is valid based on the one or more ephemeris validity indicators. For example, the wireless device may determine whether one or more timers have expired, or an absolute time has passed.
  • the wireless device refreshes (e.g., updates, requests, re-acquires, etc.) the ephemeris data for the one or more satellites. For example, the wireless device may refresh its ephemeris data according to any of the embodiments and examples described herein.
  • the wireless device upon determining ephemeris data for the one or more satellites is valid, performs a network operation (e.g., uplink synchronization, synchronization signal block (SSB) measurement, etc.) based on the ephemeris data for the one or more satellites. Additional examples of network operations are described with respect to the embodiments and examples described above.
  • the wireless device performs a random access procedure. For example, after determining the ephemeris data is not valid, the wireless device may perform a random access procedure to re-acquire uplink synchronization information (e.g., timing advance).
  • FIGURE 8 is a flowchart illustrating an example method in a network node, according to certain embodiments. In particular embodiments, one or more steps of FIGURE 8 may be performed by network node 160 described with respect to FIGURE 5.
  • the method begins at step 812, where the network node (e.g., network node 160) determines one or more ephemeris data validity indicators for ephemeris data associated with one or more satellites.
  • the network node may obtain the ephemeris data validity indicators from another network node, such as a core network node, or the network node may determine the ephemeris data validity indicators based on its own knowledge of the associated satellites.
  • the network node transmits the one or more ephemeris data validity indicators to a wireless device.
  • the ephemeris data validity indicators are described with respect to FIGURE 7, and with respect to the embodiments and examples described above.
  • FIGURE 9 illustrates a schematic block diagram of two apparatuses in a wireless network (for example, the wireless network illustrated in FIGURE 5).
  • the apparatuses include a wireless device and a network node (e.g., wireless device 110 and network node 160 illustrated in FIGURE 5).
  • Apparatuses 1600 and 1700 are operable to carry out the example methods described with reference to FIGURES 8 and 9, respectively, and possibly any other processes or methods disclosed herein. It is also to be understood that the methods of FIGURES 8 and 9 are not necessarily carried out solely by apparatus 1600 and/or apparatus 1700. At least some operations of the method can be performed by one or more other entities.
  • Virtual apparatuses 1600 and 1700 may comprise processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like.
  • the processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory, cache memory, flash memory devices, optical storage devices, etc.
  • Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein, in several embodiments.
  • the processing circuitry may be used to cause receiving module 1602, determining module 1604, and any other suitable units of apparatus 1600 to perform corresponding functions according one or more embodiments of the present disclosure.
  • the processing circuitry described above may be used to cause determining module 1704, transmitting module 1706, and any other suitable units of apparatus 1700 to perform corresponding functions according one or more embodiments of the present disclosure.
  • apparatus 1600 includes receiving module 1602 configured to receive ephemeris data including ephemeris validity information according to any of the embodiments and examples described herein.
  • Determining module 1604 is configured to determine validity of ephemeris data according to any of the embodiments and examples described herein.
  • apparatus 1700 includes determining module 1704 configured to determine validity of ephemeris data according to any of the embodiments and examples described herein.
  • Transmitting module 1706 is configured to transmit ephemeris data and ephemeris validity information to a wireless device according to any of the embodiments and examples described herein.
  • FIGURE 10 is a schematic block diagram illustrating a virtualization environment 300 in which functions implemented by some embodiments may be virtualized.
  • virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources.
  • virtualization can be applied to a node (e.g., a virtualized base station or a virtualized radio access node) or to a device (e.g., a UE, a wireless device or any other type of communication device) or components thereof and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components (e.g., via one or more applications, components, functions, virtual machines or containers executing on one or more physical processing nodes in one or more networks).
  • a node e.g., a virtualized base station or a virtualized radio access node
  • a device e.g., a UE, a wireless device or any other type of communication device
  • some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines implemented in one or more virtual environments 300 hosted by one or more of hardware nodes 330. Further, in embodiments in which the virtual node is not a radio access node or does not require radio connectivity (e.g., a core network node), then the network node may be entirely virtualized.
  • the virtual node is not a radio access node or does not require radio connectivity (e.g., a core network node)
  • the network node may be entirely virtualized.
  • the functions may be implemented by one or more applications 320 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) operative to implement some of the features, functions, and/or benefits of some of the embodiments disclosed herein.
  • Applications 320 are run in virtualization environment 300 which provides hardware 330 comprising processing circuitry 360 and memory 390.
  • Memory 390 contains instructions 395 executable by processing circuitry 360 whereby application 320 is operative to provide one or more of the features, benefits, and/or functions disclosed herein.
  • Virtualization environment 300 comprises general-purpose or special-purpose network hardware devices 330 comprising a set of one or more processors or processing circuitry 360, which may be commercial off-the-shelf (COTS) processors, dedicated Application Specific Integrated Circuits (ASICs), or any other type of processing circuitry including digital or analog hardware components or special purpose processors.
  • processors or processing circuitry 360 which may be commercial off-the-shelf (COTS) processors, dedicated Application Specific Integrated Circuits (ASICs), or any other type of processing circuitry including digital or analog hardware components or special purpose processors.
  • Each hardware device may comprise memory 390-1 which may be non-persistent memory for temporarily storing instructions 395 or software executed by processing circuitry 360.
  • Each hardware device may comprise one or more network interface controllers (NICs) 370, also known as network interface cards, which include physical network interface 380.
  • NICs network interface controllers
  • Each hardware device may also include non-transitory, persistent, machine-readable storage media 390-2 having stored therein software 395 and/or instructions executable by processing circuitry 360.
  • Software 395 may include any type of software including software for instantiating one or more virtualization layers 350 (also referred to as hypervisors), software to execute virtual machines 340 as well as software allowing it to execute functions, features and/or benefits described in relation with some embodiments described herein.
  • Virtual machines 340 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 350 or hypervisor. Different embodiments of the instance of virtual appliance 320 may be implemented on one or more of virtual machines 340, and the implementations may be made in different ways.
  • processing circuitry 360 executes software 395 to instantiate the hypervisor or virtualization layer 350, which may sometimes be referred to as a virtual machine monitor (VMM).
  • VMM virtual machine monitor
  • Virtualization layer 350 may present a virtual operating platform that appears like networking hardware to virtual machine 340.
  • hardware 330 may be a standalone network node with generic or specific components. Hardware 330 may comprise antenna 3225 and may implement some functions via virtualization. Alternatively, hardware 330 may be part of a larger cluster of hardware (e.g., such as in a data center or customer premise equipment (CPE)) where many hardware nodes work together and are managed via management and orchestration (MANO) 3100, which, among others, oversees lifecycle management of applications 320.
  • CPE customer premise equipment
  • MANO management and orchestration
  • NFV network function virtualization
  • NFV may be used to consolidate many network equipment types onto industry standard high-volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.
  • virtual machine 340 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine.
  • Each of virtual machines 340, and that part of hardware 330 that executes that virtual machine be it hardware dedicated to that virtual machine and/or hardware shared by that virtual machine with others of the virtual machines 340, forms a separate virtual network elements (VNE).
  • VNE virtual network elements
  • VNF Virtual Network Function
  • one or more radio units 3200 that each include one or more transmitters 3220 and one or more receivers 3210 may be coupled to one or more antennas 3225.
  • Radio units 3200 may communicate directly with hardware nodes 330 via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station.
  • control system 3230 which may alternatively be used for communication between the hardware nodes 330 and radio units 3200.
  • a communication system includes telecommunication network 410, such as a 3GPP-type cellular network, which comprises access network 411, such as a radio access network, and core network 414.
  • Access network 411 comprises a plurality of base stations 412a, 412b, 412c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 413a, 413b, 413c.
  • Each base station 412a, 412b, 412c is connectable to core network 414 over a wired or wireless connection 415.
  • a first UE 491 located in coverage area 413c is configured to wirelessly connect to, or be paged by, the corresponding base station 412c.
  • a second UE 492 in coverage area 413a is wirelessly connectable to the corresponding base station 412a. While a plurality of UEs 491, 492 are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station 412.
  • Telecommunication network 410 is itself connected to host computer 430, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm.
  • Host computer 430 may be under the ownership or control of a service provider or may be operated by the service provider or on behalf of the service provider.
  • Connections 421 and 422 between telecommunication network 410 and host computer 430 may extend directly from core network 414 to host computer 430 or may go via an optional intermediate network 420.
  • Intermediate network 420 may be one of, or a combination of more than one of, a public, private or hosted network; intermediate network 420, if any, may be a backbone network or the Internet; in particular, intermediate network 420 may comprise two or more sub-networks (not shown).
  • the communication system of FIGURE 11 as a whole enables connectivity between the connected UEs 491, 492 and host computer 430.
  • the connectivity may be described as an over-the-top (OTT) connection 450.
  • Host computer 430 and the connected UEs 491, 492 are configured to communicate data and/or signaling via OTT connection 450, using access network 411, core network 414, any intermediate network 420 and possible further infrastructure (not shown) as intermediaries.
  • OTT connection 450 may be transparent in the sense that the participating communication devices through which OTT connection 450 passes are unaware of routing of uplink and downlink communications. For example, base station 412 may not or need not be informed about the past routing of an incoming downlink communication with data originating from host computer 430 to be forwarded (e.g., handed over) to a connected UE 491. Similarly, base station 412 need not be aware of the future routing of an outgoing uplink communication originating from the UE 491 towards the host computer 430.
  • FIGURE 12 illustrates an example host computer communicating via a base station with a user equipment over a partially wireless connection, according to certain embodiments.
  • Example implementations, in accordance with an embodiment of the UE, base station and host computer discussed in the preceding paragraphs will now be described with reference to FIGURE 12.
  • host computer 510 comprises hardware 515 including communication interface 516 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of communication system 500.
  • Host computer 510 further comprises processing circuitry 518, which may have storage and/or processing capabilities.
  • processing circuitry 518 may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions.
  • Host computer 510 further comprises software 511, which is stored in or accessible by host computer 510 and executable by processing circuitry 518.
  • Software 511 includes host application 512.
  • Host application 512 may be operable to provide a service to a remote user, such as UE 530 connecting via OTT connection 550 terminating at UE 530 and host computer 510. In providing the service to the remote user, host application 512 may provide user data which is transmitted using OTT connection 550.
  • Communication system 500 further includes base station 520 provided in a telecommunication system and comprising hardware 525 enabling it to communicate with host computer 510 and with UE 530.
  • Hardware 525 may include communication interface 526 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of communication system 500, as well as radio interface 527 for setting up and maintaining at least wireless connection 570 with UE 530 located in a coverage area (not shown in FIGURE 12) served by base station 520.
  • Communication interface 526 may be configured to facilitate connection 560 to host computer 510.
  • Connection 560 may be direct, or it may pass through a core network (not shown in FIGURE 12) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system.
  • hardware 525 of base station 520 further includes processing circuitry 528, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions.
  • processing circuitry 528 may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions.
  • Base station 520 further has software 521 stored internally or accessible via an external connection.
  • Communication system 500 further includes UE 530 already referred to. Its hardware 535 may include radio interface 537 configured to set up and maintain wireless connection 570 with a base station serving a coverage area in which UE 530 is currently located. Hardware 535 of UE 530 further includes processing circuitry 538, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions.
  • UE 530 further comprises software 531, which is stored in or accessible by UE 530 and executable by processing circuitry 538.
  • Software 531 includes client application 532. Client application 532 may be operable to provide a service to a human or non-human user via UE 530, with the support of host computer 510.
  • an executing host application 512 may communicate with the executing client application 532 via OTT connection 550 terminating at UE 530 and host computer 510.
  • client application 532 may receive request data from host application 512 and provide user data in response to the request data.
  • OTT connection 550 may transfer both the request data and the user data.
  • Client application 532 may interact with the user to generate the user data that it provides.
  • host computer 510, base station 520 and UE 530 illustrated in FIGURE 12 may be similar or identical to host computer 430, one of base stations 412a, 412b, 412c and one of UEs 491, 492 of FIGURE 5, respectively. This is to say, the inner workings of these entities may be as shown in FIGURE 12 and independently, the surrounding network topology may be that of FIGURE 5.
  • OTT connection 550 has been drawn abstractly to illustrate the communication between host computer 510 and UE 530 via base station 520, without explicit reference to any intermediary devices and the precise routing of messages via these devices.
  • Network infrastructure may determine the routing, which it may be configured to hide from UE 530 or from the service provider operating host computer 510, or both. While OTT connection 550 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., based on load balancing consideration or reconfiguration of the network).
  • Wireless connection 570 between UE 530 and base station 520 is in accordance with the teachings of the embodiments described throughout this disclosure.
  • One or more of the various embodiments improve the performance of OTT services provided to UE 530 using OTT connection 550, in which wireless connection 570 forms the last segment. More precisely, the teachings of these embodiments may improve the signaling overhead and reduce latency, and thereby provide benefits such as reduced user waiting time, better responsiveness and extended battery life.
  • a measurement procedure may be provided for monitoring data rate, latency and other factors on which the one or more embodiments improve.
  • There may further be an optional network functionality for reconfiguring OTT connection 550 between host computer 510 and UE 530, in response to variations in the measurement results.
  • the measurement procedure and/or the network functionality for reconfiguring OTT connection 550 may be implemented in software 511 and hardware 515 of host computer 510 or in software 531 and hardware 535 of UE 530, or both.
  • sensors (not shown) may be deployed in or in association with communication devices through which OTT connection 550 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above or supplying values of other physical quantities from which software 511, 531 may compute or estimate the monitored quantities.
  • the reconfiguring of OTT connection 550 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect base station 520, and it may be unknown or imperceptible to base station 520. Such procedures and functionalities may be known and practiced in the art.
  • measurements may involve proprietary UE signaling facilitating host computer 510’s measurements of throughput, propagation times, latency and the like.
  • the measurements may be implemented in that software 511 and 531 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using OTT connection 550 while it monitors propagation times, errors etc.
  • FIGURE 13 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment.
  • the communication system includes a host computer, a base station and a UE which may be those described with reference to FIGURES 11 and 12. For simplicity of the present disclosure, only drawing references to FIGURE 13 will be included in this section.
  • step 610 the host computer provides user data.
  • substep 611 (which may be optional) of step 610, the host computer provides the user data by executing a host application.
  • step 620 the host computer initiates a transmission carrying the user data to the UE.
  • step 630 (which may be optional), the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure.
  • step 640 (which may also be optional), the UE executes a client application associated with the host application executed by the host computer.
  • FIGURE 14 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment.
  • the communication system includes a host computer, a base station and a UE which may be those described with reference to FIGURES 11 and 12. For simplicity of the present disclosure, only drawing references to FIGURE 14 will be included in this section.
  • step 710 of the method the host computer provides user data.
  • the host computer provides the user data by executing a host application.
  • step 720 the host computer initiates a transmission carrying the user data to the UE.
  • the transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure.
  • step 730 (which may be optional), the UE receives the user data carried in the transmission.
  • FIGURE 15 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment.
  • the communication system includes a host computer, a base station and a UE which may be those described with reference to FIGURES 11 and 12. For simplicity of the present disclosure, only drawing references to FIGURE 15 will be included in this section.
  • step 810 the UE receives input data provided by the host computer. Additionally, or alternatively, in step 820, the UE provides user data. In substep 821 (which may be optional) of step 820, the UE provides the user data by executing a client application. In substep 811 (which may be optional) of step 810, the UE executes a client application which provides the user data in reaction to the received input data provided by the host computer. In providing the user data, the executed client application may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the UE initiates, in substep 830 (which may be optional), transmission of the user data to the host computer. In step 840 of the method, the host computer receives the user data transmitted from the UE, in accordance with the teachings of the embodiments described throughout this disclosure.
  • FIGURE 16 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment.
  • the communication system includes a host computer, a base station and a UE which may be those described with reference to FIGURES 11 and 12. For simplicity of the present disclosure, only drawing references to FIGURE 16 will be included in this section.
  • the base station receives user data from the UE.
  • the base station initiates transmission of the received user data to the host computer.
  • the host computer receives the user data carried in the transmission initiated by the base station.
  • the term unit may have conventional meaning in the field of electronics, electrical devices and/or electronic devices and may include, for example, electrical and/or electronic circuitry, devices, modules, processors, memories, logic solid state and/or discrete devices, computer programs or instructions for carrying out respective tasks, procedures, computations, outputs, and/or displaying functions, and so on, as such as those that are described herein.

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Abstract

Selon certains modes de réalisation, un procédé est mis en œuvre par un dispositif sans fil capable de fonctionner dans un réseau non terrestre (NTN). Le procédé comprend les étapes consistant à : obtenir des données d'éphémérides destinées à au moins un satellite ; obtenir au moins un indicateur de validité de données d'éphémérides pour les données d'éphémérides destinées à l'au moins un satellite ; déterminer si les données d'éphémérides destinées à l'au moins un satellite sont valides sur la base de l'au moins un indicateur de validité de données d'éphéméride ; et lors de la détermination que les données d'éphémérides destinées à l'au moins un satellite ne sont pas valides, rafraîchir les données d'éphémérides destinées à l'au moins un satellite.
PCT/SE2022/050745 2021-08-05 2022-08-05 Validité de données d'éphémérides pour des réseaux non terrestres WO2023014277A1 (fr)

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Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
3GPP TR 38.811
3GPP TR 38.821
3GPP TS 38.213
ZTE: "Discussion on UL synchronization for NR-NTN", vol. RAN WG1, no. e-Meeting; 20210510 - 20210527, 12 May 2021 (2021-05-12), XP052011268, Retrieved from the Internet <URL:https://ftp.3gpp.org/tsg_ran/WG1_RL1/TSGR1_105-e/Docs/R1-2105190.zip R1-2105190 Discussion on UL synchronization for NR-NTN.docx> [retrieved on 20210512] *

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