Method and device for moving from a first cell to a second cell - Patents.com

Abstract

A method and system for assisting a user equipment in moving from a first cell to a second cell in a communication system is described. An embodiment includes triggering the transmission of ephemeris data or other data in a neighboring cell into which the user equipment is moving. While in the first cell, the user equipment can send a request to trigger the broadcast of data in the neighboring cell according to configuration information. The user equipment can then enter the neighboring cell and receive the data.

Description

[Technical field]

[0001] Cross-references to related information This application claims the benefit of Patent Cooperation Treaty priority application No. PCT / CN2020 / 136278, filed December 14, 2020, entitled "Methods and Devices for Moving from First Cell to Second Cell," the contents of which are incorporated herein in their entirety.

[0002] The present disclosure relates generally to the field of wireless communications. [Background technology]

[0003] Under the 3rd Generation Partnership (3GPP) 5th Generation (5G) / New Radio (NR) background, the Evolved Packet System (EPS) was specified in 3GPP Release 8. EPS is based on the Long-Term Evolution (LTE) radio network and the Evolved Packet Core (EPC). EPS was initially intended to provide voice and mobile broadband (MBB) services, but it has been continuously evolving to expand the capabilities of EPS, and since Release 13, Narrowband (NB) Internet of Things (IoT) and LTE Machine-to-Machine (LTE-M) are part of the LTE specification, providing connectivity to Massive Machine-Type Communications (mMTC) services.

[0004] 3GPP Release 15 specified the first release of 5G Systems (5GS), a new generation of radio access technology intended to serve use cases such as enhanced Mobile Broadband (eMBB), ultra-reliable low latency communications (URLLC) and mMTC. 5G includes the New Radio (NR) access hierarchical interface and the 5G Core Network (5GC). The NR physical layer and higher layers reuse parts of the LTE specification and add required components to that part of the LTE specification as motivated by new use cases.

[0005] In Release 15, 3GPP also started work to prepare NR for operation in non-terrestrial networks (NTN). The work was carried out within the study item "NR for supporting non-terrestrial networks" and resulted in TR 38.811. In Release 16, 3GPP started work to prepare NR for operation in NTN networks, and the work continued in the study item "Solutions for NR to support non-terrestrial networks", the results of which were documented in TR 38.821. In parallel, there is growing interest in adapting LTE for operation in NTN. As a result, 3GPP is considering introducing support for NTN in both LTE and NR in Release 17.

[0006] A satellite radio access network typically includes the following components: satellites, which refer to spaceborne platforms; earth-based gateways that connect the satellites to base stations or to a core network depending on the architecture chosen; feeder links, which refer to the links between the gateways and the satellites; and access links (also called service links), which refer to the links between the satellites and UEs (User Equipment).

[0007] Depending on the orbital altitude, satellites may be categorized as Low Earth Orbit (LEO), Medium Earth Orbit (MEO), or Geostationary Earth Orbit (GEO) satellites. · LEO: Typical altitudes range from 250 to 1,500 km, and orbital periods range from 90 to 120 minutes. · MEO: Typical altitudes range from 5,000 to 25,000 km, and orbital periods range from 3 to 15 hours. GEO: Approximately 35,786 km altitude, with an orbital period of 24 hours.

[0008] The significant orbital altitude means that satellite systems are characterized by path losses significantly higher than would be expected in terrestrial networks. To overcome the path losses, it is often required that the access and feeder links be operated in line-of-sight conditions, and that the UEs be equipped with antennas that provide high beam directionality.

[0009] A communication satellite typically generates several beams over a given area. The footprint of a beam is usually elliptical in shape, which has traditionally been considered a cell. The footprint of a beam is often also called a spot beam. The spot beam may move across the Earth's surface with the satellite moving (called a moving beam cell case / deployment) or may be Earth fixed with some beam pointing mechanism used by the satellite to compensate for its movement (called an Earth fixed beam case / deployment). The size of the spot beam depends on the system design and can range from tens of kilometers to thousands of kilometers.

[0010] Two basic architectures are considered: transparent payload and regenerative payload. In a transparent system (also called bent-pipe architecture), the next generation Node B (gNB) is located on the ground and a satellite forwards signals / data between the gNB and the UE. In a regenerative system, the gNB is located in the satellite. In the work item for NR NTN in 3GPP Release 17, only the transparent architecture is considered.

[0011] FIG. 1 illustrates an example architecture of a satellite network 50 with bent-pipe transponders. A satellite 13 provides communication capabilities to a UE, such as device 9. The satellite 13 may serve one or more of spot beams 1, 2, 3, 4. Another satellite, such as satellite 17, may serve one or more of spot beams 1, 2, 3, 4. A base station 16 may be co-located with a gateway 15. The satellite 13 communicates with the gateway 15 via a feeder link 11 and with the device 9 via an access link 12. As described further below, the device 9 may be moving from one spot beam (e.g., spot beam 4) to another spot beam (e.g., spot beam 1). In such a case, the neighboring spot beams 1 may be served by the same satellite 13 or by a different satellite 17. Embodiments under the present disclosure include methods and systems for triggering satellites serving spot beam 1 to send ephemeris data or other data, whereby when device 9 arrives in a new spot beam 1, device 9 receives the sent data.

[0012] NTN beams are very wide compared to beams observed in terrestrial networks and may cover areas outside the area defined by the served cell. Beams covering adjacent cells may overlap, causing significant levels of inter-cell interference. To overcome large levels of interference, a common approach in NTN is to configure different cells with different carrier frequencies and polarization modes.

[0013] In TR 38.821, it is captured that ephemeris data should be provided to the UE, for example, to assist in pointing a directional antenna (or antenna beam) towards the satellite, and to calculate the correct timing advance (TA) and Doppler shift (which are also called time pre-compensation and frequency pre-compensation, respectively, when derived autonomously by the UE). The procedure on how ephemeris data should be provided and updated has not yet been studied in detail.

[0014] A satellite orbit can be fully described using six parameters. Exactly which set of parameters is chosen can be determined by the user, and many different representations are possible. For example, a choice of parameters often used in astronomy is the set (a, ε, i, Ω, ω, t), where the semimajor axis a and eccentricity ε describe the shape and size of the orbital ellipse, the inclination i, the right ascension of the ascending node Ω, and the argument of the periapsis ω determine its position in space, and the epoch t determines the reference time (e.g., the time when the satellite moves through the periapsis). This set of parameters, called orbital elements, is illustrated in FIG. 2.

[0015] As an example of a different parameterization, the Two Line Element (TLE) set format uses mean motion n and mean anomaly M instead of a and t. An entirely different set of parameters are the satellite position and velocity vectors (x, y, z, vx, vy, vz). These are sometimes called orbital state vectors. They can be derived from the orbital elements and vice versa, since the information they contain is equivalent. All these formats (and many others) are possible choices for the format of ephemeris data to be used in the NTN. To allow further progress, the format of the data should be agreed upon by the parties involved in any given network.

[0016] Another aspect discussed in the study item and captured in TR 38.821 is the validity time of the ephemeris data. Predictions of satellite positions in general deteriorate with increasing age of the ephemeris data used due to atmospheric drag, satellite maneuvering, imperfections in the orbital model used, etc. Therefore, publicly available TLE data is updated very frequently. The update frequency depends on the satellite and the satellite's orbit, and ranges from weekly to multiple times a day for satellites in very low orbits that are subject to strong atmospheric drag and need to perform frequent corrective maneuvers.

[0017] Thus, while it may appear possible to provide satellite positions with the required accuracy, care needs to be taken to meet these requirements, for example, when choosing the ephemeris data format, or the orbital model to be used for orbital propagation, as well as when considering how often the ephemeris data provided should be updated.

[0018] System Information (SI) is an important function in cellular communication systems. SI provides the UE with information required to access the network and to perform other functions, such as reselecting between cells and receiving Multimedia Broadcast Multicast Service (MBMS) transmissions in cellular networks operating according to 3GPP standards. Additionally, in 3GPP cellular systems, the SI mechanism is used to convey public warning system messages, such as Earthquake and Tsunami Warning System (ETWS) messages and Commercial Mobile Alert System (CMAS) messages. In LTE, SI is provided using periodic broadcasting in each cell. SI is divided into a Master Information Block (MIB) and several System Information Blocks (SIBs). MIB and SIB1 are broadcasted with a period fixed in the standard. Other SIBs are broadcasted with different periods set in SIB1.

[0019] For the 5G system called New Radio (NR) (where the RAN is called Next Generation Radio Access Network (NG-RAN) and the core network is called Next Generation Core (NGC)), 3GPP has partially changed the principle for the delivery of system information (SI) used in LTE. For NR, the SI is divided into "minimum SI" and "other SI", where the minimum SI is the SI required to access the cell, and in the case of NR standalone mode (i.e. not dual connectivity setup with LTE), the minimum SI also contains the scheduling information for the SIBs of the other SI. The minimum SI comprises the Master Information Block (MIB) and the System Information Block type 1 (SIB1). SIB1 is also called "Residual Minimum System Information" (RMSI). At least in NR standalone mode, the minimum SI is broadcast periodically in the cell, and the other SI can either be broadcast periodically or delivered on demand triggered by a request from the UE. The granularity of the division into periodically broadcasted SI and on-demand SI is at the level of the SI message. Whether an SI message is broadcast periodically or provided on demand is indicated in SIB1 (e.g., using the si-BroadcastStatus parameter). A UE in RRC_IDLE, RRC_INACTIVE or RRC_CONNECTED state can request an on-demand SI message either using a random access preamble (referred to as the Msg1-based method) or using a random access message 3 (referred to as the Msg3-based method). If a random access preamble (Msg1) transmission is used, there can be different preambles for requesting different SI messages of other SI (and consequently, SIBs assigned to the SI messages). The mapping between the random access preamble and the SI message to be requested is set in SIB1.If random access message 3 (Msg3) transmission is used, the UE may specify in such a message which SI messages of other SIs (and consequently SIBs assigned to the SI messages) the UE wants the network to broadcast / transmit. A request for an on-demand SI message triggers the network to broadcast the requested SI message for a limited time according to the scheduling information associated with the related SI message in SIB1. The network also transmits an acknowledgement message to the requesting UE. In the case of the Msg1-based request method, the network responds with an acknowledgement random access message 2 (Msg2). In the case of the Msg3-based request method, the network responds with an acknowledgement random access message 4 (Msg4).

[0020] The periodic broadcast of SI is designed in NR largely according to the same principles as in LTE. As in LTE, the Master Information Block (MIB) is transmitted at a fixed location with respect to the synchronization signal. The situation for SIB1 is slightly different in NR than in LTE. The periodicity of SIB1 is 160 ms, but SIB1 can be repeated several times within this 160 ms, and the transmission configuration is indicated in the MIB. The remaining SIBs are scheduled in SIB1 and transmitted on the Physical Downlink Shared Channel (PDSCH) in the same way as in LTE. Different SIBs can have different periodicities. SIBs with the same periodicity are assigned to the same SI message, and every SI message is associated with a periodic SI-window within which the SI message should be transmitted. The SI-windows of different SI messages have different periodicities, are non-overlapping, and they all have the same duration. It should be noted that the exact transmission opportunity of the SI message is not set, only the window within which the SI message is transmitted. To indicate that a PDSCH transmission contains an SI message, the cyclic redundancy check (CRC) of the physical downlink control channel (PDCCH) that schedules the downlink control information (DCI) that allocates the PDSCH transmission resource is scrambled with the system information-radio network temporary identifier (SI-RNTI). The receiving UE exploits the non-overlapping nature of the SI-windows to identify which SI message it receives (and therefore which SIB it contains), and the SI messages do not have any indication in themselves to distinguish one SI message from another. The principle of allocating SIBs to SI messages and scheduling SI messages in SI-windows is illustrated in Figure 4. Each SI message is transmitted in its own SI-window, and the temporal occurrence of the SI-window depends on the SI message periodicity and the position of the SI message in the list in SIB1.

[0021] It should be noted that every SI message has a set schedule, regardless of whether the SI message is broadcast periodically or provided on demand, in which case the scheduled broadcast opportunity is only utilized when the network, i.e. the gNB, receives a request for the relevant SI message.

[0022] 3 and 4A-4B show the ASN.1 definition of the SI scheduling related parameters in SIB1 and the associated field descriptions.

[0023] The basic principles for SI updates in NR are the same as in LTE. It is built around the concept of SI modification periods. With some exceptions, SI can only be updated at the boundary points between two SI modification periods. Moreover, planned SI updates must be announced in an SI modification period prior to the actual SI update. Such announcement is performed using a paging mechanism, in other words, a notification on the paging channel is used to inform UEs in RRC_IDLE, RRC_INACTIVE, and RRC_CONNECTED about the upcoming system information changes. In NR, the notification of the upcoming SI update is conveyed via a so-called "short message", in other words, included in the DCI (with CRC scrambled with P-RNTI) on the PDCCH with or without an associated scheduled paging message on the PDSCH. If the UE receives a DCI that includes a short message with a systemInfoModification indication, the UE knows that the system information will change at the next SI modification period boundary.

[0024] A special case of SI update notification via short message on paging channel is when the etwsAndCmasIndication parameter in the short message indicates that a public alert system message (ETWS or CMAS) has been activated (or changed) in the SI. In this case, the UE knows that the update is immediately applicable and that the UE should acquire and read the SIB related to the relevant public alert as soon as possible. The UE has to read SIB1 to find out whether the notification is related to ETWS or CMAS.

[0025] SI updates are hereby signaled via the paging channel, and as a consequence UEs must monitor the paging channel not only to receive pages targeted at them but also to receive possible SI update notifications (including PWS notifications). UEs in RRC_IDLE and RRC_INACTIVE states may monitor their regular Paging Occasions (POs), i.e. one PO per paging DRX cycle, and UEs in RRC_CONNECTED state may monitor POs for SI update notifications, but should monitor at least one PO per default paging cycle (pointed to by the defaultPagingCycle parameter in SIB1). Summary of the Invention

[0026] An embodiment under the present disclosure includes a method implemented by a user equipment (UE) for moving from a first cell to a second cell, where the first cell is a serving cell of the UE and the second cell includes one of one or more neighbor cells. The method includes sending a request in the first cell to trigger broadcasting of information data in the second cell according to configuration information prior to moving from the first cell to the second cell, and receiving the broadcasted information data in the second cell.

[0027] Another embodiment may include a method implemented by a first network node for moving a UE from a first cell associated with the first network node to a second cell, the first cell being a serving cell for the UE. The method may include receiving a request from the UE in the first cell to trigger broadcasting of information data in the second cell, and determining whether the second cell is served by the first network node or the second network node. If the second cell is served by the second network node, the request is forwarded to the second network node for broadcasting of the information data. If the second cell is served by the first network node, the requested information data is broadcast in the second cell.

[0028] Another embodiment may include a method implemented by a second network node for moving a UE from a first cell to a second cell associated with the second network node, where the first cell is a serving cell of the UE and is controlled by the first network node, and the second cell includes one of one or more neighbor cells of the first cell. The method may include receiving a request from the first network node to trigger broadcasting of information data in the second cell. The method may optionally further include broadcasting the requested information data in the second cell and / or determining whether to accept the request to broadcast the information data in the second cell.

[0029] Another embodiment may comprise a UE comprising a processor and a memory. The memory stores a computer program that, when executed on the processor, causes the processor to perform a method for moving from a first cell to a second cell, where the first cell is a serving cell of the UE and the second cell includes one of one or more neighbor cells. The method includes sending a request to a base station associated with the first cell while being served in the first cell to trigger a broadcast of information data in the second cell according to configuration information prior to moving from the first cell to the second cell, and receiving the information data broadcast by the second base station associated with the second cell.

[0030] A further embodiment may comprise a first network node comprising a processor and a memory storing a computer program which, when executed on the processor, causes the processor to perform a method for moving a UE from a first cell associated with the first network node to a second cell, the first cell being a serving cell for the UE, the method comprising receiving, in the first cell, a request from the UE to trigger broadcasting of information data in the second cell, determining whether the second cell is served by the first network node or by the second network node, forwarding the request for broadcasting of the information data to the second network node if the second cell is served by the second network node, and broadcasting the requested information data in the second cell if the second cell is served by the first network node.

[0031] An additional embodiment may comprise a second network node comprising a processor and a memory storing a computer program that, when executed on the processor, causes the processor to perform a method for moving a UE from a first cell to a second cell associated with the second network node, where the first cell is a serving cell of the UE and is controlled by the first network node and the second cell includes one of one or more neighbor cells of the first cell. The method may include receiving a request from the first network node to trigger broadcasting of information data in the second cell.

[0032] A further embodiment may comprise a non-transitory computer-readable storage medium having stored thereon a computer program that, when executed on at least one processor, causes the at least one processor to perform a method according to any one of the embodiments described herein.

[0033] This Summary has been provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an indication of the scope of the claimed subject matter.

[0034] For a more complete understanding of the present disclosure, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: [Brief description of the drawings]

[0035] [Figure 1] FIG. 1 illustrates a schematic diagram of a bent-pipe satellite network architecture under the present disclosure. [Diagram 2] FIG. 2 is a diagram showing a schematic diagram of orbital elements to explain a satellite orbit. [Diagram 3] A diagram showing the ASN.1 definition of SI scheduling related parameters in SIB1. [Figure 4A]FIG. 13 shows an explanation of the columns for SI-related parameters in SIB1. [Figure 4B] FIG. 13 shows an explanation of the columns for SI-related parameters in SIB1. [Diagram 5] FIG. 13 shows a schematic diagram of allocating SIBs to SI messages and scheduling SI messages in an SI-window. [Figure 6] FIG. 2 illustrates a schematic flowchart of a method implemented by a UE for moving from a first cell to a second cell according to an embodiment of the present disclosure. [Figure 7] FIG. 2 illustrates a schematic flowchart of a method implemented by a UE for moving from a first cell to a second cell according to an embodiment of the present disclosure. [Figure 8] FIG. 2 illustrates a schematic flow chart of a method implemented by a first network node for moving from a first cell to a second cell according to an embodiment of the present disclosure. [Figure 9] FIG. 2 illustrates a schematic flow chart of a method implemented by a first network node for moving from a first cell to a second cell according to an embodiment of the present disclosure. [Figure 10] FIG. 2 illustrates a schematic flow chart of a method implemented by a second network node for moving from a first cell to a second cell according to an embodiment of the present disclosure. [Figure 11] FIG. 2 illustrates a schematic flow chart of a method implemented by a second network node for moving from a first cell to a second cell according to an embodiment of the present disclosure. [Figure 12] FIG. 2 illustrates a schematic block diagram of a UE according to an embodiment of the present disclosure. [Figure 13] FIG. 2 illustrates a schematic block diagram of a first network node according to an embodiment of the present disclosure. [Figure 14] FIG. 2 illustrates a schematic block diagram of a second network node according to an embodiment of the present disclosure. [Figure 15]FIG. 1 is a diagram illustrating a schematic of a communication network connected to a host computer via an intermediate network. [Figure 16] FIG. 2 is a generalized block diagram of a host computer communicating with user equipment via a base station over a partially wireless connection. [Figure 17] 1 is a flow chart illustrating a method implemented in a communication system including a host computer, a base station, and user equipment. [Figure 18] 1 is a flow chart illustrating a method implemented in a communication system including a host computer, a base station, and user equipment. [Figure 19] 1 is a flow chart illustrating a method implemented in a communication system including a host computer, a base station, and user equipment. [Figure 20] 1 is a flow chart illustrating a method implemented in a communication system including a host computer, a base station, and user equipment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] Before describing various embodiments of the present disclosure in detail, it should be understood that the present disclosure is not limited to the parameters of the specifically illustrated systems, methods, devices, products, processes, and / or kits, which may, of course, vary. Thus, although some embodiments of the present disclosure are described in detail with respect to specific settings, parameters, components, elements, etc., the descriptions are illustrative and should not be construed as limiting the scope of the claimed embodiments. Additionally, the terminology used herein is for the purpose of describing the embodiments and is not necessarily intended to limit the scope of the claimed embodiments.

[0037] There are a number of problems with existing solutions. As can be seen from the above, NTN UEs rely on access to ephemeris data for satellites in the NTN for efficient operation. However, broadcasting ephemeris data in the system information causes additional control signaling overhead, especially in the moving beam deployment case.

[0038] In the following discussion, specific details of certain embodiments of the present techniques are described for purposes of explanation and not limitation. It will be appreciated by those skilled in the art that other embodiments may be employed apart from these specific details. Moreover, in some instances, detailed descriptions of well-known methods, nodes, interfaces, circuits, and devices are omitted so as not to obscure the description with unnecessary detail.

[0039] Terms such as "base station," "user equipment," "access point," and "network node" used herein should be understood in a broad sense, since various wireless systems may benefit from utilizing the ideas covered within this disclosure, as will be appreciated by those skilled in the art. Specifically, a base station should be understood to encompass a legacy base station in a second generation (2G) network, a Node B in a third generation (3G) network, an evolved Node B (eNodeB) in a fourth generation (4G), a gNB in ​​a fifth generation (5G) or NR network or future evolved networks (e.g., an LTE network, an LTE-Advanced (LTE-A) network, etc.). A user equipment should be understood to encompass a mobile phone, a smartphone, a wireless-enabled tablet or personal computer, a wireless machine-to-machine unit, etc. Moreover, in an NR NTN, a UE sees a cell, but not necessarily a satellite. In this specification, the term "serving satellite" should be understood as a satellite serving a serving cell of a UE (in other words, a satellite that transmits signals / data in and receives signals / data from the serving cell of the UE). Similarly, the term "neighbor satellite" should be understood as a satellite serving a neighbor cell. Depending on the context, a neighbor cell may be a cell that is neighboring the serving cell of the UE (from the perspective of the UE) or a cell served by a neighbor satellite that is neighboring at least one of the cells served by the satellite (from the perspective of the satellite or the perspective of the gNB that uses the satellite). (i.e., from the satellite / gNB perspective, two satellites are neighbors if at least one of the cells served by one of the satellites is neighboring at least one of the cells served by the other satellite).

[0040] To address the problems described above, the present disclosure includes multiple embodiments of systems and methods for situations where a UE moves from one cell to another, such as in the case of a moving beam. The proposed embodiments of the present disclosure include a method by which a UE may send a signal or request in the UE's serving cell to trigger / request broadcasting of satellite ephemeris data in neighbor cells. The ephemeris data for which broadcast is requested should be ephemeris data associated with the satellite serving the concerned neighbor cell. This may be useful for a UE that is about to reselect to the concerned neighbor cell, or for a UE that is about to be handed over to a neighbor cell, for example, because the UE is about to perform a conditional handover to the neighbor cell. The UE may use either the SI request method, or another type of request, for example, a dedicated RRC message in RRC_CONNECTED state, to request broadcasting of full ephemeris data in neighbor cells.

[0041] If the Msg1-based SI request method is used, there may be one preamble configured for this type of request for each of the listed set of neighbor cells, where the set size may be one or multiple cells (as is the case in all subsequent examples where sets are mentioned). As another option, one (dedicated) preamble is configured for each of the listed set of satellites. In this case, the satellites may be identified with some kind of identifier, or the preamble may be associated instead in the configuration information with a set of neighbor cells, where all neighbor cells in such a set are served by the same neighbor satellite. As yet another option, one preamble may be configured for the request of ephemeris data broadcast in all neighbor cells in the listed set of neighbor cells.

[0042] As yet another option, if a dedicated preamble is configured for the ephemeris data request in each listed neighbor cell (possibly except for neighbor cells served by the UE's current serving satellite), the configuration data in the serving cell may also point to neighbor cells served by the same satellite (e.g., neighbor cells may be grouped by satellite or each neighbor cell may have an associated satellite identifier). Another option is that an indicator, e.g., a one-bit flag, is associated with each of the listed neighbor cells to indicate whether the cell is served by the current serving satellite (in other words, the satellite serving the UE's current serving cell) or by another satellite. The benefit of conveying this type of information to the UE may be that a UE that has already (e.g., recently) collected ephemeris data in one of the neighbor cells from the information may conclude that some other neighbor cells are served by the same satellite, and the UE may consequently refrain from requesting that ephemeris data be broadcast in this other neighbor cell, e.g., before performing cell reselection to that neighbor cell. As another option, the cells served by one satellite may be collected in subgroups, in which case some broadcast information applies only to such subgroup of cells, e.g., PLMN or TAI. Yet another option is that an indicator, e.g., a one-bit flag, is associated with each of the listed neighbor cells, indicating whether a dedicated preamble should be used for that particular cell, which allows for implicit grouping of cells with respect to the serving satellite (in other words, the satellite serving the UE's current serving cell) or with respect to another satellite.

[0043] In another embodiment, a preamble configured for ephemeris data request is broadcast in the cell via the MIB or SIB (preferably SIB1 or SIB2), so that the UE can send the request, for example, once a candidate cell for camping or handover has been identified. In a variant, the above described embodiments can be combined so that the UE can know in advance whether a particular cell is served by the same satellite before sending such a request.

[0044] If the Msg3-based SI request method is used, the requesting UE may indicate in the request message (in the random access Msg3) in which neighbor cells it would like the ephemeris data to be broadcasted. Optionally, the UE may also indicate details regarding the ephemeris data it would like to be broadcasted, e.g., which parameters to broadcast, which ephemeris data format (in other words, which satellite orbit representation format / parameters) to use for the broadcast information, and / or the desired accuracy of the broadcast information. If a message other than the random access Msg3 is used, such as an RRC message used in the RRC_CONNECTED state, such an indication regarding details of the ephemeris data requested to be broadcasted may also be included.

[0045] In addition to the existing Msg1 and Msg3 based SI request methods, it is possible to use a method based on two-step random access for requesting ephemeris data broadcasted in neighbor cells. For example, the MsgA based SI request method may be used, where the request and possible details, such as the involved cell, ephemeris data format and / or parameters (as described above for the case where Msg3 based SI request is used), are included in the PUSCH part of the MsgA. One scenario where the MsgA based method may be beneficial is when only two-step random access is configured in the serving cell (or BWP) (in other words, four-step random access is not configured in the serving cell (or BWP)). Another motivation for the MsgA-based method is that, unlike the case with the Msg3-based method, MsgA comprises both a random access preamble (corresponding to Msg1) and a message on the PUSCH (corresponding to Msg3), and the MsgA-based method saves one message round trip compared to the Msg3-based method, since the random access preamble (Msg1) and the random access response (Msg2) do not need to be exchanged before sending the actual request. Although the MsgA-based SI request method is not specified in 3GPP Release 16, such a method may be introduced in a later release of the 3GPP standard, either for NR in general or only for NR adapted for use in NTNs.

[0046] As one option, the involved gNB may introduce a short additional delay before broadcasting the requested ephemeris data to give the UE enough time to synchronize with the neighbor cell's downlink before the requested ephemeris data is broadcast. As one option, the size of this delay may be included in the configuration data in the serving cell that configures the ephemeris data broadcast request method and / or lists the involved neighbor cells. As another option, if the UE uses a request / trigger method for requesting ephemeris data broadcast in neighbor cells that allows for indication of additional details (e.g., the Msg3-based SI request method, the MsgA-based SI request method or another message such as an RRC message used in RRC_CONNECTED state), the UE may request such a delay or indicate a time at which the broadcast should (or preferably should) be made or indicate a time interval within which the broadcast should (one or more times) be made or the number of requested broadcast repetitions and / or the frequency of the broadcast repetitions (e.g., in the form of a requested repetition interval). Such indications regarding timing, delay, interval, number of repetitions etc. may thereby be included in the random access Msg3, the two-step random access MsgA (PUSCH part) or in the RRC messages used in the RRC_CONNECTED state.

[0047] As yet another option, after sending the request for broadcast of ephemeris data in neighbor cells, the UE may start a timer or a time window for the UE to monitor the downlink in the concerned neighbor cell for reception of the requested ephemeris data broadcast. In one variation of this option, if the timer or time window expires and the UE has not received the requested ephemeris data broadcast in the neighbor cell, the UE repeats its sending of the request in the serving cell to trigger broadcast of the ephemeris data in the serving cell. In another variation of this option, if the UE does not receive the requested ephemeris data broadcast in a neighbor cell, the UE is proactive and repeats its request message in the serving cell before the timer or time window expires until the ephemeris data can be received, in order to reduce delays and to reduce the risk that the channel quality in the serving cell degrades too much for successful transmission of the request (e.g., if the UE is moving from the serving cell to the neighbor cell and is about to reselect to or be handed over to the neighbor cell). Optionally, the UE's timer or time window may coincide with a corresponding timer or time window in the gNB controlling the relevant neighbor cell, where timing coordination may be performed between the serving gNB and the gNB controlling the neighbor cell in cooperation with the serving gNB, and may forward the request to the gNB controlling the neighbor cell.

[0048] FIG. 6 shows a schematic flowchart of a method 400 implemented by a UE for moving from a first cell to a second cell according to a possible embodiment of the present disclosure. In the method 400, the first cell is a serving cell of the UE, and the second cell is a neighbor cell of one or more neighbor cells. The first cell and the second cell may be cells in an NTN using an Earth moving beam or in a terrestrial network. The first cell is controlled by, for example, a first network node. The second cell is controlled by, for example, a second network node. The first network node may be, for example, a network device (e.g., gNB) in an NTN. The second network node may be, for example, another network device (e.g., gNB) in an NTN that is neighbor to the first network node. As an embodiment, the method 400 includes the following steps 401-402.

[0049] In step 401, before moving from a first cell to a second cell, the UE transmits a signal (e.g., a request) in the first cell to trigger broadcasting of information data in the second cell according to configuration information. The configuration information may refer to configuration information from an O&M system, or from a core network node, or from a field technician, or configuration during manufacturing or customer adaptation, or hard-coded information created during programming or product design. For example, the configuration information may be used to configure which method should be used to trigger broadcasting of information data in the second cell, to configure the resources used for one or more of the methods, e.g., PRACH preamble configuration for msg1-based method, and so on. In an example, the UE may transmit a request to trigger broadcasting of information data in one or more neighbor cells by using an SI request, an ephemeris data request using a random access preamble, or a message related to a random access procedure, a random access Msg3, a two-step random access MsgA, and / or a dedicated RRC message request. The SI request may include one or more of an Msg1-based SI request to trigger the broadcast of information data in the second cell, an Msg3-based request to trigger the broadcast of information data in the second cell, or a two-step random access-based request to trigger the broadcast of information data in the second cell. For example, in the case of an Msg1-based SI request, one or more preambles may be configured for each of the listed set of neighbor cells. Optionally, one or more preambles may be configured for each of the listed set of satellites. Optionally, one or more preambles may be configured for a set of neighbor cells served by the same satellite or for a set of neighbor cells served by different satellites. In addition, which of the one or more neighbor cells is served by the same satellite may be indicated in the configuration information or by an indicator.Moreover, one or more neighbor cells served by the same satellite may be divided into subgroups in the configuration information or by an indicator. In an example, before sending a request, the UE may obtain, in a first cell, configuration information for a request for broadcast of information data in one or more neighbor cells. In an example, for example, when the UE is in an RRC_IDLE or RRC_INACTIVE state, the UE may send a request before performing cell reselection to the second cell. As another example, for example, when the UE is in an RRC_CONNECTED state, the UE may send a request before performing a handover to the second cell.

[0050] In step 402, the UE receives information data broadcasted in the second cell. The information data may be satellite ephemeris data broadcasted via system information (SI). The information data may also be other types of information or system information, or other parts of the system information, or selected parts of the system information. The satellite ephemeris data may include satellite orbits, position and velocity information, and information about inter-node propagation paths / links, such as feeder link propagation delays and / or feeder link Doppler shifts (between the satellite and the gateway). In an example, before receiving the information data, the UE may receive a response message approving or rejecting the request, and if a response message approving the request is received, the UE starts monitoring downlink transmissions in the second cell for information data. In an example, the UE may receive satellite ephemeris data broadcasted in the second cell along with a "common timing advance" and / or a "common Doppler shift" associated with a reference location in the second cell. Here, when the timing and / or frequency related information is associated with a reference location, e.g., a central location of a neighbor cell, the associated timing and / or frequency related information may be referred to as a "common timing advance" and / or a "common Doppler shift". In an example, the UE may start a timer that governs a time period during which the UE must wait until the requested information data is received. When the timer expires, the UE may retransmit the request in the first cell. Optionally, the UE may also retransmit the request in the first cell after a backoff time when the timer expires. The backoff time is set for better overload and access control. As an example, the UE may calculate a time pre-compensation and / or a frequency pre-compensation to be applied to an uplink transmission in the second cell by using the received information data.

[0051] FIG. 7 shows a possible embodiment of a method 700 implemented by a UE served by an NTN (in RRC_IDLE, RRC_INACTIVE or RRC_CONNECTED state) according to the present disclosure. Step 710 is to obtain, in a first (serving) cell, configuration data that configures a method for requesting broadcast of satellite ephemeris data in one or more neighbor cells. Step 720 is to determine the need to switch to a second cell, where the second cell is one of the one or more neighbor cells. Step 730 is to transmit, in the first cell, a request to have satellite ephemeris data broadcast in the second cell. Step 740 is to (optionally) receive a grant of the request. Step 750 is to monitor downlink transmissions in the second cell. Step 760 is to receive satellite ephemeris data (optionally supplemented with other relevant data) in the second cell. Step 770 is to use the received data to calculate time and / or frequency pre-compensation to be applied to uplink transmissions, e.g., random access preamble transmissions, in the second cell. In step 730, the UE may optionally start a timer that governs how long the UE expects to wait up to receive the requested satellite ephemeris data in the second cell, where expiration of the timer may trigger the UE to retransmit the request in the first (serving) cell.

[0052] On the network side, the involved nodes ensure that the request for ephemeris data broadcast is conveyed to the node responsible for performing the broadcast. A corresponding positive response (or negative response, e.g., a rejection of the request) may also be returned from the node responsible for performing the broadcast, which may be forwarded all the way to the requesting UE. This may involve, for example, an inter-satellite link in case of a regenerative payload deployment architecture, where the Xn (inter-gNB) interface is carried on the inter-satellite link. It may also involve, for example, a terrestrial link, e.g., an inter-gNB link, in a transparent payload deployment architecture, where the Xn (inter-gNB) interface is carried on the terrestrial transport network link. Some possible inter-node paths include: Serving satellite → (GW) → (terrestrial) gNB → (GW) → Naver satellite, Serving satellite → (GW) → (terrestrial) gNB → (terrestrial) gNB → (GW) → Naver satellite, Serving satellite → (GW) → (terrestrial) gNB (where the gNB is responsible for broadcasting the ephemeris data via different cells and possibly via different satellites), Serving satellite → (GW) → (terrestrial)gNB → (terrestrial)gNB (where the gNB is responsible for broadcasting the ephemeris data via another cell and possibly via another satellite), Serving satellite (with on-board DU) → (GW) → (terrestrial) CU → (GW) → Neighbor satellite (with on-board DU), Serving satellite (with on-board DU) → (GW) → (terrestrial) CU → (another gNB's) (terrestrial) CU → (GW) → Neighbor satellite (with on-board DU), Serving satellite (with on-board DU) → (GW) → (terrestrial) CU (where the CU is responsible for broadcasting the ephemeris data via different cells and possibly via different satellites), Serving satellite (with on-board DU) → (GW) → (terrestrial) CU → (terrestrial) CU (of another gNB), where the CU is responsible for broadcasting the ephemeris data via another cell and possibly via another satellite, and Serving satellite (with on-board gNB) → Neighbor satellite (with on-board gNB).

[0053] If a positive response (or negative response) is sent to the requesting UE, this may be sent in a random access Msg2 if the Msg1-based SI request method is used, or in a random access Msg4 if the Msg3-based SI request method is used, in MsgB if the MsgA-based SI request method is used, or in a dedicated RRC message if a dedicated RRC message is used for the request (e.g. in RRC_CONNECTED state).

[0054] 8 shows a schematic flow chart of a method 500 implemented by a first network node for moving a UE from a first cell associated with the first network node to a second cell, where the first cell is a serving cell for the UE. In the method 500, the first cell is a serving cell of the UE and is controlled by the first network node, and the second cell is one of one or more neighbor cells controlled by the second network node. The method 500 includes the following steps 501-504.

[0055] In step 501, the first network node receives, in the first cell, a signal (e.g., a request) from the UE to trigger broadcasting of information data in the second cell. In an example, before receiving the signal, the first network node may obtain configuration information related to a manner for the UE to request broadcasting of information data in one or more neighbor cells. Alternatively, before receiving the signal, the first network node may configure the UE using system information broadcasted in the first cell with information related to a manner for requesting broadcasting of information data in one or more neighbor cells. In an example, for example, when the UE is in an RRC_IDLE or RRC_INACTIVE state, the first network node may receive the request before performing cell reselection to the second cell. In another example, for example, when the UE is in an RRC_CONNECTED state, the first network node may receive the request before performing handover to the second cell.

[0056] In step 502, the first network node determines whether the second cell is served by the first network node or the second network node. In an example, if the second cell is served by the first network node, the first network node may determine whether to accept the request to broadcast information data in the second cell. In an example, if the second cell is served by the second network node, the first network node may receive a response message from the second network node approving or denying the request to broadcast information data in the second cell. In an example, the first network node may send a response message to the UE approving or denying the request to broadcast information data in the second cell.

[0057] If the second cell is served by the second network node, the first network node forwards the request for broadcasting of the information data to the second network node in step S503, and if the second cell is served by the first network node, the first network node broadcasts the requested information data in the second cell in step 504. In an example, the first network node may broadcast the requested information data in the second cell one or more times within a time interval, at a specified time, after a delay, according to the configuration information or a request from the UE. In an example, the first network node may broadcast satellite ephemeris data in the second cell together with a "common timing advance" and / or a "common Doppler shift" associated with a reference location in the second cell described above.

[0058] FIG. 9 displays a possible method embodiment 900 for a method implemented by a first network node in an NTN, e.g., a gNB, serving a UE (in RRC_IDLE, RRC_INACTIVE or RRC_CONNECTED state) in a serving cell (also referred to as "first cell") controlled by the first network node. The method 900 may be implemented by the first network node to assist the UE in moving from the first cell to the second cell. Step 910 is to obtain configuration information related to a method for the UE (in the serving / first cell) to request broadcast of satellite ephemeris data in one or more neighbor cells. Step 920 is to (optionally) configure the UE with information related to a method for requesting broadcast of satellite ephemeris data in one or more neighbor cells, e.g., using broadcasted system information in the first / serving cell. (Alternatively, the UE may be pre-configured or hard-coded with the configuration information, as previously described). Step 930 is to receive, in the serving / first cell, a request from the UE for broadcasting satellite ephemeris data in a second cell, where the second cell is one of one or more neighbor cells. In step 940, if the second cell is served by another second network node, send / forward the request for broadcasting satellite ephemeris data to the second network node. Optionally, in 970, the first network node can receive a response message from the second network node approving (positive response) or rejecting (negative response) the request for broadcasting satellite ephemeris data in the second cell. In step 950, if the second cell is served by the first network node, determine whether to accept the request for broadcasting satellite ephemeris data in the second cell.Optionally, in step 960, the first network node may send a response message to the UE approving (positive response) or rejecting (negative response) the request to broadcast the satellite ephemeris data in the second cell (according to an optional response received from the second network node or the decision made in step 950). In step 980, if the request from the UE is accepted, the first network node may broadcast the satellite ephemeris data in the second cell according to the accepted request (optionally after a delay due to configuration or request from the UE). It should be noted that "obtaining" in the above step 910 may include receiving information from an O&M system, or from a core network node, or from a field technician, or configuration during manufacturing or customer adaptation, or hard-coded information created during programming or product design.

[0059] FIG. 10 shows a schematic flow chart of a method 600 implemented by a second network node for moving a UE from a first cell to a second cell according to an embodiment of the present disclosure. In the method 600, the first cell is a serving cell of the UE and is controlled by the first network node, and the second cell is one of one or more neighbor cells controlled by the second network node. The method 600 includes the following steps 601-602. In step 601, the second network node receives a request from the first network node to trigger broadcasting of information data in the second cell. Optionally, the second network node may decide whether to accept the request to broadcast the information data in the second cell. Thus, the second network node may send a response message to the first network node approving or rejecting the request to broadcast the information data in the second cell. In step 602 (optional in some embodiments), the second network node broadcasts the requested information data in the second cell. In an example, the second network node may broadcast the requested information data in the second cell according to the configuration information or the received request, after a delay, at a specified time, one or more times within a time interval, or multiple times. In an example, the second network node may broadcast the satellite ephemeris data in the second cell together with a "common timing advance" and / or a "common Doppler shift" associated with a reference location in the second cell as described above.

[0060] 11 shows a possible method 2100 implemented by a second network node, e.g., a gNB, in an NTN neighboring a first network node serving a UE (in RRC_IDLE, RRC_INACTIVE or RRC_CONNECTED state) in a serving cell (also called "first cell") controlled by the first network node, where the second network node serves at least one second cell neighboring the serving / first cell of the UE. Step 2110 is to receive a request from the first network node to broadcast satellite ephemeris data in the second cell. Step 2120 is to decide whether to accept the request to broadcast satellite ephemeris data in the second cell. Optionally, in step 2130, the second network node may send a response message to the first network node approving (positive response) or rejecting (negative response) the request to broadcast the satellite ephemeris data in the second cell (according to the outcome of the decision in step 2120). In 2140, if the outcome of the decision in step 2120 was to accept the request, the second network node may broadcast the requested satellite ephemeris data in the second cell (optionally after a delay depending on the configured or received request).

[0061] In a variant of all the above embodiments, the broadcasted satellite ephemeris data (in other words orbit and position / velocity information) may be complemented by information about the satellite's feeder links, such as feeder link propagation (or round trip) delay and / or feeder link Doppler shift, and / or information about the GW, e.g. GW location, and / or information about the gNB (in terrestrial, in other words transparent payload architecture), e.g. gNB location, and / or information about the GW-gNB link (if any), e.g. GW-gNB propagation (or round trip) delay, information about the GW-CU link (if any), e.g. GW-CU propagation (or round trip) delay. Moreover, if the method for supporting the UE's calculation of pre-compensation timing advance and / or Doppler shift frequency pre-compensation in the concerned neighbor cell is based on timing and / or frequency related information associated with a reference location, e.g., the central location of the neighbor cell, this reference location and preferably its associated timing and / or frequency related information, such as a "common timing advance" and / or a "common Doppler shift", may be broadcast together with the ephemeris data in the neighbor cell, either by default as specified by the standard specification, or upon indication in the request sent by the UE (and forwarded to the gNB associated to the satellite serving the concerned neighbor cell). This may facilitate the UE to calculate the residual timing and / or frequency compensation (e.g., to compensate for the Doppler shift) in order to arrive at a precise pre-compensation timing advance and / or a precise pre-compensation frequency shift.

[0062] Although the embodiments described above focused on a scenario in which the UE wants ephemeris data to be broadcast in the cell to which the UE is moving, the embodiments under the present disclosure may be applied to other information, e.g., other types of information or system information or other parts of system information. An example may be access-related information, e.g., if a resource saving scheme is applied and this information is broadcast infrequently or is periodic, available only on demand, in which case a request prior to entering the cell is beneficial and speeds up the access procedure in the new cell. Another example may be a precise timestamp that the UE may use (together with a time reference derived from a Global Navigation Satellite System (GNSS) (e.g., Global Positioning System (GPS)) satellite) to calculate a pre-compensated timing advance (and / or, e.g., a pre-compensated frequency shift to compensate for Doppler shift) to be used in the new cell.

[0063] The above embodiments have been described with respect to a UE being served in a cell in an NTN. However, the proposed solution is also applicable in a scenario where the UE is served in a cell in a terrestrial network, e.g., a cellular network employing radio access technology (RAT) NR or LTE. In such a scenario, the UE may be switching (through cell reselection or handover) to a cell in an NTN, where the proposed solution may be applied. Moreover, the proposed solution may also be applicable when both the serving cell and the relevant neighbor cell are served by a terrestrial network, although in that scenario the information required to be broadcast in the neighbor cell is of another type than satellite ephemeris data. Furthermore, an additional scenario in which the embodiments of the present disclosure may be applied is when the UE is served in a cell in an NTN and the relevant neighbor cell belongs to a terrestrial network. In summary, the proposed solution can be applied in scenarios with any combination of network types (i.e. terrestrial network or NTN) of the involved cells (i.e. serving cell and neighbor cell), with the constraint that in scenarios where the involved neighbor cells belong to a terrestrial network, the option to request broadcast of satellite ephemeris data in the neighbor cells is not applicable and the information requested to be broadcast is instead of another type, e.g. system information related to access settings or access constraints in the involved neighbor cells.

[0064] 12-14 respectively show schematic block diagrams of a UE 700, a first network node 800 and a second network node 900 according to an embodiment of the present disclosure.

[0065] The UE 700, the first network node 800 and the second network 900 may each include at least one processor 701, 801, 901 and at least one memory 702, 802, 902, as shown in Figures 12-14. As shown in Figure 12, the memory 702 stores a computer program that, when executed on the processor 701, causes the processor 701 to perform any of the methods implemented in the UE 700 according to the present disclosure. As shown in Figure 13, the memory 802 stores a computer program that, when executed on the processor 801, causes the processor 801 to perform any of the methods implemented in the first network node 800 according to the present disclosure. As shown in Figure 14, the memory 902 stores a computer program that, when executed on the processor 901, causes the processor 901 to perform any of the methods implemented in the first network node 900 according to the present disclosure.

[0066] The memory may be, for example, an electrically erasable programmable read-only memory (EEPROM), a flash memory, and a hard drive. The processor may be a single CPU (Central Processing Unit), but may also comprise two or more processing units. For example, the processor may include a general-purpose microprocessor, an instruction set processor and / or related chipset, and / or a special-purpose microprocessor such as an application specific integrated circuit (ASIC). The processor may also comprise on-board memory for caching purposes. The computer program may be carried by a computer program product connected to the processor. The computer program product may comprise a computer readable medium on which the computer program is stored. For example, the computer program product may be a flash memory, a random access memory (RAM), a read only memory (ROM), or an EEPROM, and the computer program modules may be distributed on different computer program products in the form of memory in the UE or network node in alternative embodiments.

[0067] In an embodiment of the present disclosure, a computer readable storage medium is provided having stored thereon a computer program which, when executed on at least one processor, causes the at least one processor to perform a method according to the present disclosure.

[0068] According to an embodiment of the present disclosure, a UE can trigger the broadcast of system information or satellite ephemeris data in another cell by transmitting a signal in the UE's serving cell. In a preferred embodiment, the signal can be a PRACH preamble configured to be dedicated for this purpose, possibly combined with some PRACH transmission resources. In one exemplary embodiment, the UE can be in an RRC_IDLE or RRC_INACTIVE state and sends such a signal before performing cell reselection to the other concerned cell. In another embodiment, the UE can be in an RRC_CONNECTED state and sends the signal before performing a handover (e.g., a conditional handover) to the other concerned cell.

[0069] FIG. 15 illustrates generally a communications network connected to a host computer via an intermediate network.

[0070] Referring to Fig. 15, according to an embodiment, a communication system includes a communication network 1010, such as a 3GPP type cellular network, comprising an access network 1011, such as a wireless access network, and a core network 1014. The access network 1011 comprises a number of base stations 1012a, 1012b, 1012c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 1013a, 1013b, 1013c. Each base station 1012a, 1012b, 1012c is connectable to the core network 1014 via a wired or wireless connection 1015. A first user equipment (UE) 1091 located in the coverage area 1013c is configured to wirelessly connect to or be paged by the corresponding base station 1012c. A second UE 1092 in the coverage area 1013a can wirelessly connect to the corresponding base station 1012a. Although multiple UEs 1091, 1092 are shown in this example, the disclosed embodiments are equally applicable to situations where only one UE is in the coverage area or connected to the corresponding base station 1012.

[0071] A UE 1091, 1092 may be moving from one coverage area 1013a, 1013b, 1013c to another coverage area and may need to trigger transmission of ephemeris or other data in the neighboring cell to which the UE is moving. The method of triggering transmission of data may be practiced by the first base station (e.g., 1012a), the second base station (e.g., 1012b), or the UE (e.g., 1092) in various embodiments described herein.

[0072] The communication network 1010 is itself connected to a host computer 1030, which may be embodied in hardware and / or software of a standalone server, a cloud-implemented server, a distributed server, or as a processing resource in a server farm. The host computer 1030 may be owned or under the control of a service provider, or may be operated by or on behalf of the service provider. The connection 1021, 1022 between the communication network 1010 and the host computer 1030 may extend directly from the core network 1014 to the host computer 1030, or may proceed via an optional intermediate network 1020. The intermediate network 1020 may be one of a public network, a private network, or a hosted network, or a combination of two or more of them, and the intermediate network 1020 may be a backbone network or the Internet, if any, and in particular the intermediate network 1020 may comprise two or more sub-networks (not shown).

[0073] The communication system of FIG. 15 as a whole enables connectivity between one of the connected UEs 1091, 1092 and the host computer 1030. The connectivity may be described as an over-the-top (OTT) connection 1050. The host computer 1030 and the connected UEs 1091, 1092 are configured to communicate data and / or signaling via the OTT connection 1050 using the access network 1011, the core network 1014, any intermediate networks 1020 and possible further infrastructure (not shown) as intermediaries. The OTT connection 1050 may be transparent in the sense that the participating communication devices through which the OTT connection 1050 passes are unaware of the routing of the uplink and downlink communications. For example, the base station 1012 may not be or need not be informed about the past routing of an incoming downlink communication involving data originating from the host computer 1030 to be forwarded (e.g., handed over) to the connected UE 1091. Similarly, the base station 1012 does not need to be aware of the future routing of outgoing uplink communications originating from the UE 1091 and destined for the host computer 1030 .

[0074] FIG. 16 is a generalized block diagram of a host computer that communicates with user equipment via a base station over a partially wireless connection. Next, an exemplary implementation of the UE, base station and host computer discussed in the previous paragraph according to an embodiment will be described with reference to FIG. 16. In the communication system 1100, the host computer 1110 comprises hardware 1115 including a communication interface 1116 configured to set up and maintain a wired or wireless connection with interfaces of different communication devices of the communication system 1100. The host computer 1110 further comprises a processing circuit 1118, which may have storage and / or processing capabilities. In particular, the processing circuit 1118 may comprise one or more programmable processors, application specific integrated circuits, field programmable gate arrays, or combinations thereof adapted to execute instructions (not shown). The host computer 1110 further comprises software 1111, which is stored in or accessible by the host computer 1110 and is executable by the processing circuit 1118. The software 1111 includes a host application 1112. The host application 1112 may be operable to provide services to a remote user, such as a UE 1130 connecting via an OTT connection 1150 that terminates at the UE 1130 and the host computer 1110. In providing services to the remote user, the host application 1112 may provide user data that is transmitted using the OTT connection 1150.

[0075] The communication system 1100 further includes a base station 1120 provided in the communication system, the base station 1120 comprising hardware 1125 enabling the base station 1120 to communicate with the host computer 1110 and the UE 1130. The hardware 1125 may include a communication interface 1126 for setting up and maintaining wired or wireless connections with interfaces of different communication devices of the communication system 1100, as well as a wireless interface 1127 for setting up and maintaining at least a wireless connection 1170 with a UE 1130 located in a coverage area (not shown in FIG. 16) served by the base station 1120. The communication interface 1126 may be configured to facilitate a connection 1160 to the host computer 1110. The connection 1160 may be direct, or the connection 1160 may pass through a core network (not shown in FIG. 16) of the communication system and / or one or more intermediate networks outside the communication system. In the embodiment shown, the hardware 1125 of the base station 1120 further includes processing circuitry 1128, which may comprise one or more programmable processors, application specific integrated circuits, field programmable gate arrays, or combinations thereof adapted to execute instructions (not shown). The base station 1120 further has software 1121 stored internally or accessible via an external connection.

[0076] The communication system 1100 further includes the UE 1130 already mentioned. The hardware 1135 of the UE 1130 may include a wireless interface 1137 configured to set up and maintain a wireless connection 1170 with a base station serving a coverage area in which the UE 1130 is currently located. The hardware 1135 of the UE 1130 further includes a processing circuit 1138, which may comprise one or more programmable processors, application specific integrated circuits, field programmable gate arrays, or combinations thereof adapted to execute instructions (not shown). The UE 1130 further includes software 1131 stored in or accessible by the UE 1130 and executable by the processing circuit 1138. The software 1131 includes a client application 1132. The client application 1132 may be operable to provide services to a human or non-human user via the UE 1130 under the support of the host computer 1110. At the host computer 1110, a running host application 1112 may communicate with a running client application 1132 via an OTT connection 1150 that terminates at the UE 1130 and the host computer 1110. In providing services to a user, the client application 1132 may receive request data from the host application 1112 and provide user data in response to the request data. The OTT connection 1150 may transfer both the request data and the user data. The client application 1132 may interact with the user to generate the user data that the client application 1132 provides.

[0077] It should be noted that the host computer 1110, base station 1120, and UE 1130 illustrated in FIG. 16 may be equivalent to the host computer 3230, one of the base stations 3212a, 3212b, 3212c, and one of the UEs 3291, 3292, respectively, of FIG. 15. That is, the inner workings of these entities may be as shown in FIG. 16, and separately, the surrounding network topology may be that of FIG. 15. In FIG. 16, the OTT connection 1150 is drawn abstractly to illustrate the communication between the host computer 1110 and the user equipment 1130 via the base station 1120, without explicit reference to intermediate devices and the exact routing of messages through these devices. The network infrastructure may determine the routing, and the network infrastructure may be configured to be hidden from the UE 1130 or from the service provider operating the host computer 1110, or both. While the OTT connection 1150 is active, the network infrastructure may further make decisions to dynamically change the routing (e.g., based on network load balancing considerations or reconfiguration). The wireless connection 1170 between the UE 1130 and the base station 1120 follows the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of the OTT service provided to the UE 1130 using the OTT connection 1150 of which the wireless connection 1170 forms the last segment. More precisely, the teachings of these embodiments may improve latency, thereby providing benefits such as reduced user latency, better responsiveness, extended battery life, etc.

[0078] Measurement procedures may be provided for the purpose of monitoring data rates, latency, and other factors that one or more embodiments improve upon. There may further be an optional network function to reconfigure the OTT connection 1150 between the host computer 1110 and the UE 1130 in response to fluctuations in the measurement results. The measurement procedures and / or network functions to reconfigure the OTT connection 1150 may be implemented in the software 1111 of the host computer 1110, or in the software 1131 of the UE 1130, or both. In an embodiment, sensors (not shown) may be deployed in or in association with the communication devices through which the OTT connection 1150 passes, and the sensors may participate in the measurement procedures by providing values ​​of the monitored quantities exemplified above, or other physical quantities from which the software 1111, 1131 may calculate or estimate the monitored quantities. The reconfiguration of the OTT connection 1150 may include message formats, retransmission settings, preferred routing, etc., and the reconfiguration need not affect the base station 1120, and the reconfiguration may be unknown or imperceptible to the base station 1120. Such procedures and functions may be known and practiced in the art. In some embodiments, the measurements may involve proprietary UE signaling that facilitates the host computer 1110 measurements of throughput, propagation time, latency, etc. The measurements may be implemented in the software 1111, 1131 having messages, particularly empty or "dummy" messages, sent using the OTT connection 1150 while the software 1111, 1131 monitors propagation times, errors, etc.

[0079] FIG. 17 is a flow chart illustrating a method implemented in a communication system according to one embodiment. The communication system includes a host computer, a base station, and a UE, which may be as described with reference to FIG. 15 and FIG. 16. For simplicity of the disclosure, only drawing references to FIG. 17 are included in this section. In a first step 1210 of the method, the host computer provides user data. In an optional sub-step 1211 of the first step 1210, the host computer provides the user data by executing a host application. In a second step 1220, the host computer initiates a transmission carrying the user data to the UE. In an optional third step 1230, the base station transmits the user data carried in the host computer initiated transmission to the UE according to the teachings of the embodiments described throughout this disclosure. In an optional fourth step 1240, the UE executes a client application associated with the host application executed by the host computer.

[0080] FIG. 18 is a flow chart illustrating a method implemented in a communication system according to one embodiment. The communication system includes a host computer, a base station, and a UE, which may be as described with reference to FIG. 15 and FIG. 16. For simplicity of the disclosure, only drawing references to FIG. 18 are included in this section. In a first step 1310 of the method, the host computer provides user data. In an optional sub-step (not shown), the host computer provides the user data by executing a host application. In a second step 1320, the host computer initiates a transmission carrying the user data to the UE. The transmission may proceed via the base station according to the teachings of the embodiments described throughout this disclosure. In an optional third step 1330, the UE receives the user data carried in the transmission.

[0081] FIG. 19 is a flow chart illustrating a method implemented in a communication system according to one embodiment. The communication system includes a host computer, a base station, and a UE, which may be as described with reference to FIG. 15 and FIG. 16. For simplicity of the disclosure, only drawing references to FIG. 19 are included in this section. In an optional first step 1410 of the method, the UE receives input data provided by the host computer. Additionally or alternatively, in an optional second step 1420, the UE provides user data. In an optional sub-step 1421 of the second step 1420, the UE provides the user data by executing a client application. In a further optional sub-step 1411 of the first step 1410, the UE executes a client application that provides the user data in response to the received input data provided by the host computer. In providing the user data, the executed client application may further take into account user input received from the user. Regardless of the particular manner in which the user data is provided, the UE initiates transmission of the user data to the host computer in an optional third sub-step 1430. In a fourth step 1440 of the method, the host computer receives user data transmitted from the UE according to the teachings of the embodiments described throughout this disclosure.

[0082] FIG. 20 is a flow chart illustrating a method implemented in a communication system according to one embodiment. The communication system includes a host computer, a base station, and a UE, which may be as described with reference to FIG. 15 and FIG. 16. For simplicity of the disclosure, only a drawing reference to FIG. 20 is included in this section. In an optional first step 1510 of the method, the base station receives user data from the UE, according to the teachings of the embodiments described throughout this disclosure. In an optional second step 1520, the base station initiates a transmission of the received user data to the host computer. In a third step 1530, the host computer receives the user data carried in the transmission initiated by the base station.

[0083] The present disclosure includes any novel feature or combination of features explicitly disclosed herein, or any generalization thereof. Various modifications and adaptations to the above exemplary embodiments of the present disclosure may become apparent to those skilled in the relevant art in view of the above description, when read in conjunction with the accompanying drawings. However, any and all modifications will still fall within the scope of the non-limiting exemplary embodiments of the present disclosure.

[0084] Computer system of the present disclosure It will be appreciated that computer systems are increasingly taking on a wide variety of forms. In this description and in the claims, the terms "controller," "computer system," or "computing system" are broadly defined to include any device or system or combination thereof that includes at least one physical and tangible processor, and physical and tangible memory capable of having computer-executable instructions thereon that can be executed by the processor. By way of example and not limitation, the term "computer system" or "computing system" as used herein is intended to include devices not traditionally considered computing systems, such as personal computers, desktop computers, laptop computers, tablets, handheld devices (e.g., cell phones, PDAs, pagers), microprocessor-based or programmable consumer electronics, minicomputers, mainframe computers, multiprocessor systems, network PCs, distributed computing systems, data centers, message processors, routers, switches, and even wearables (e.g., glasses).

[0085] Memory may take any form and may depend on the nature and form of the computing system. Memory may be physical system memory, including volatile memory, non-volatile memory, or some combination of the two. The term "memory" is sometimes used herein to refer to non-volatile mass storage, such as a physical storage medium.

[0086] A computing system also has a number of structures thereon that are often referred to as "executable components." For example, the memory of a computing system may contain executable components. The term "executable components" is a name for structures that are well understood by those skilled in the art of computing to be structures that may be software, hardware, or a combination thereof.

[0087] For example, when implemented in software, those skilled in the art will appreciate that the structure of an executable component may include software objects, routines, methods, etc. that may be executed by one or more processors on a computing system, regardless of whether such executable component resides in the heap of the computing system or whether the executable component resides on a computer-readable storage medium. The structure of the executable component resides on a computer-readable medium in a form that, when executed by one or more processors of the computing system, is operable to cause the computing system to perform one or more functions, such as the functions and methods described herein. Such a structure may be directly computer readable by a processor, such as when the executable component is binary. Alternatively, the structure may be configured to be interpretable and / or compiled, whether in a single step or multiple steps, to generate binary numbers that are directly interpretable by a processor.

[0088] The term "executable component" will also be well understood by those skilled in the art to include structures implemented entirely or almost entirely with hardware logic components within, such as a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a program specific standard product (ASSP), a system on a chip (SOC), a complex programmable logic device (CPLD), or any other specialized circuit. Thus, the term "executable component" is a term for structures, whether implemented in software, hardware, or a combination thereof, as will be well understood by those skilled in the art of computing.

[0089] The terms "component," "service," "engine," "module," "control," "generator," and the like may also be used in this description. These terms as used in this description, and as used herein, whether expressed with or without a modifier clause, are also intended to be synonymous with the term "executable component," and thus have the same structure well understood by those of ordinary skill in the computing arts.

[0090] In an embodiment, the communication system may include a complex of computing devices performing any of the methods of the embodiments described above and data storage devices, which may be server parks and data centers.

[0091] With respect to computer implementations, a computer is generally understood to comprise one or more processors or one or more controllers, and the terms computer, processor, and controller may be employed interchangeably. When provided by a computer, processor, or controller, the functions may be provided by a single dedicated computer or processor or controller, by a single shared computer or processor or controller, or by multiple individual computers or processors or controllers, some of which may be shared or distributed. Moreover, the terms "processor" or "controller" also refer to other hardware capable of performing such functions and / or running software, such as the exemplary hardware recited above.

[0092] In general, various exemplary embodiments may be implemented in hardware or dedicated chips, circuits, software, logic, or any combination thereof. For example, some aspects may be implemented in hardware, and other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device, but the present disclosure is not limited thereto. Although various aspects of the exemplary embodiments of the present disclosure may be illustrated and described as block diagrams, flow charts, or using some other diagrammatic representation, it should be fully understood that these blocks, apparatus, systems, techniques, or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, dedicated circuits or logic, general-purpose hardware or controllers or other computing devices, or any combination thereof.

[0093] Although not all computing systems require a user interface, in some embodiments a computing system includes a user interface for use in communicating information to and from a user. A user interface may include output mechanisms as well as input mechanisms. The principles described herein are not limited to the exact output or input mechanisms and thus depend on the nature of the device. However, output mechanisms may include, for example, speakers, displays, haptic output, projections, holograms, etc. Examples of input mechanisms may include, for example, microphones, touch screens, projections, holograms, cameras, keyboards, stylus, mouse or other pointer input, any type of sensor, etc.

[0094] Thus, the embodiments described herein may comprise or utilize a special-purpose or general-purpose computing system. The embodiments described herein also include physical and other computer-readable media for carrying or storing computer-executable instructions and / or data structures. Such computer-readable media may be any available media that can be accessed by a general-purpose or special-purpose computing system. Computer-readable media that store computer-executable instructions are physical storage media. Computer-readable media that carry computer-executable instructions are transmission media. Thus, by way of example, and not limitation, the embodiments disclosed or contemplated herein may comprise at least two distinctly different kinds of computer-readable media: storage media and transmission media.

[0095] Computer-readable storage media include RAM, ROM, EEPROM, solid-state drives ("SSD"), flash memory, phase-change memory ("PCM"), CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other physical and tangible storage medium that can be used to store desired program code in the form of computer-executable instructions or data structures, and that can be accessed and executed by a general-purpose or special-purpose computing system to implement one or more functions disclosed. For example, computer-executable instructions can be embodied on one or more computer-readable storage media to form a computer program product.

[0096] Transmission media may include a network and / or data links that may be used to carry desired program code in the form of computer-executable instructions or data structures, which may be accessed and executed by a general-purpose or special-purpose computing system. Combinations of the above are also intended to be included within the scope of computer-readable media.

[0097] Furthermore, upon reaching various computing system components, program code in the form of computer-executable instructions or data structures may be automatically transferred from transmission media to storage media (or vice versa). For example, computer-executable instructions or data structures received over a network or data link may be buffered in RAM in a network interface module (e.g., a "NIC") and then eventually transferred to computing system RAM and / or to a less volatile storage medium in the computing system. It should thus be understood that storage media may be included in computing system components that also utilize transmission media or even primarily utilize transmission media.

[0098] Those skilled in the art will further appreciate that a computing system may also include communication channels that enable the computing system to communicate with other computing systems, for example, over a network. Thus, the methods described herein may be practiced in network computing environments involving many types of computing systems and computing system configurations. The disclosed methods may also be practiced in distributed system environments in which local and / or remote computing systems linked through a network (either by wired data links, wireless data links, or a combination of wired and wireless data links) both perform tasks. In a distributed system environment, processing, memory, and / or storage capabilities may also be distributed.

[0099] Those skilled in the art will also appreciate that the disclosed methods may be practiced in a cloud computing environment. A cloud computing environment may be distributed, but this is not required. When distributed, a cloud computing environment may be distributed internationally within an organization and / or may have components owned across multiple organizations. In this description and in the claims that follow, "cloud computing" is defined as a model for enabling on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services). The definition of "cloud computing" is not limited to any of the numerous other benefits that may be obtained from such a model when properly deployed.

[0100] Cloud computing models may consist of various characteristics, such as on-demand self-service, broad network access, resource pooling, high-speed elasticity, metered services, etc. Cloud computing models may come in the form of various service models, such as, for example, Software as a Service ("SaaS"), Platform as a Service ("PaaS"), and Infrastructure as a Service ("IaaS"). Cloud computing models may be deployed using different deployment models, such as private cloud, community cloud, public cloud, hybrid cloud, etc.

[0101] Abbreviations and Specified Terms To aid in understanding the scope and content of the specification and the appended claims, certain selected terms are directly defined below. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0102] As used herein, the terms "approximately," "about," and "substantially" describe an amount or condition that is close to a particular stated amount or condition that still performs a desired function or achieves a desired result. For example, the terms "approximately," "about," and "substantially" can refer to an amount or condition that deviates from a specifically stated amount or condition by less than 10%, or by less than 5%, or by less than 1%, or by less than 0.1%, or by less than 0.01%.

[0103] Various aspects of the present disclosure, including devices, systems, and methods, may be illustrated with respect to one or more embodiments or implementations that are exemplary in nature. As used herein, the term "exemplary" means "serving as an example, instance, or illustration" and is not necessarily to be construed as preferred or advantageous over other embodiments disclosed herein. Additionally, reference to an "implementation" of the present disclosure or an embodiment includes specific reference to one or more embodiments thereof, and vice versa, and is intended to provide an illustrative example without limiting the scope of the present disclosure, which is indicated by the appended claims and not by this specification.

[0104] As used herein, words appearing in the singular include their plural counterparts, and words appearing in the plural include their singular counterparts, unless otherwise understood or stated, either implicitly or explicitly. Hereby, it should be noted that the singular forms "a," "an," and "the," as used in this specification and the appended claims, include plural referents, unless the context clearly dictates otherwise. For example, a reference to a singular referent (e.g., "a widget") includes one, two, or more referents, unless otherwise understood or stated, either implicitly or explicitly. Similarly, a reference to a plural referent should be construed as comprising a single referent and / or a plurality of referents, unless the content and / or context clearly dictates otherwise. For example, a reference to a referent in a plural form (e.g., "widgets") does not necessarily require a plurality of such referents. Instead, unless stated otherwise, it will be appreciated that one or more of a referent is contemplated herein regardless of the presumed number of referents.

[0105] As used herein, directional terms such as "upper," "lower," "left," "right," "upper," "lower," "superior," "lower," "proximal," "distal," "adjacent," etc., are used herein only to indicate relative directions and are not intended to otherwise limit the scope of the present disclosure and / or the claimed embodiments.

[0106] References herein to "one embodiment," "an embodiment," "exemplary embodiment," and the like indicate that the embodiment being described may include a particular feature, structure, or characteristic, but do not require that every embodiment include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Furthermore, it is submitted that when a particular feature, structure, or characteristic is described with respect to an embodiment, it is within the knowledge of one of ordinary skill in the art to effect such feature, structure, or characteristic with respect to other embodiments, whether or not explicitly described.

[0107] Terms such as "first" and "second" may be used herein to describe various elements, but it should be understood that these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element, without departing from the scope of the exemplary embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed terms.

[0108] It will be further understood that the terms "comprises," "comprising," "has," "having," "includes," and / or "including," as used herein, specify the presence of stated features, elements, and / or components, etc., but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0109] The following abbreviations are used in this disclosure: 3GPP 3rd Generation Partnership Project BS base station BWP Bandwidth Part CMAS Commercial Mobile Alert System CRC Cyclic Redundancy Check CU Central Unit DCI Downlink Control Information DRX Intermittent reception DU Distributed Unit ETWS Earthquake and Tsunami Warning System GEO geostationary orbit gNB (including NR NTN) Radio base station in NR GW Gateway ID Identification information / identifier IE Information Elements LEO low earth orbit LTE Long Term Evolution MAC Media Access Control MEO Intermediate Earth Orbit MO Measurement Target Msg Message NR new radio NTN Non-Terrestrial Network O&M operation and maintenance PBCH Physical Broadcast Channel PLMN Public Land Mobile Network PO Paging Opportunities PRACH Physical Random Access Channel P-RNTI Paging RNTI PUSCH Physical Uplink Shared Channel RA Random Access RACH Random Access Channel RAT Radio Access Technology RNTI Radio Network Temporary Identifier RRC Radio Resource Control SI System Information SIB System Information Block SS Sync Signal SSB (also called SS / PBCH block) synchronization signal block TA Timing Advance TAI Tracking Area Identification TLE 2 Line Element Set TR technical report TS Technical Specifications UE User Equipment WI Work Item Xn (including NR NTN) Interface between two gNBs in NR

[0110] conclusion It should be understood that for any given component or embodiment described herein, any of the possible candidates or alternatives listed for that component may generally be used individually or in combination with one another, unless otherwise understood or stated, either implicitly or explicitly. In addition, any listing of such candidates or alternatives will be understood to be illustrative only, not limiting, unless otherwise understood or stated, either implicitly or explicitly.

[0111] Additionally, unless otherwise indicated, numbers expressing quantities, components, distances, or other measurements used in the specification and claims should be understood to be modified by the term "about" as that term is defined herein. Thus, unless otherwise indicated, the numerical parameters set forth in this specification and the appended claims are approximations that may vary depending on the desired properties sought to be obtained by the subject matter presented herein. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed at least in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the subject matter presented herein are approximations, the numerical values ​​set forth in the specific examples are reported as precisely as possible. However, any numerical values ​​inherently contain some errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0112] Any headings and sub-headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims.

[0113] The terms and phrases employed herein are used as terms of description and not as terms of limitation, and there is no intention in the use of such terms and phrases to exclude any equivalents of the features or portions thereof shown and described, and it is recognized that various modifications are possible within the scope of the present disclosure. Thus, although the present disclosure has been specifically disclosed, in part, by preferred embodiments, exemplary embodiments, and optional features, it is to be understood that modifications and variations of the concepts disclosed herein may be employed by those skilled in the art, and such modifications and variations are deemed to be within the scope of the present disclosure.

[0114] It will also be appreciated that systems, devices, products, kits, methods, and / or processes according to some embodiments of the present disclosure may include, incorporate, or otherwise comprise properties or features (e.g., components, members, elements, parts, and / or portions) described in other embodiments disclosed and / or described herein. Thus, various features of some embodiments may be compatible with, combined with, included in, and / or incorporated into other embodiments of the present disclosure. Thus, the disclosure of some features for a particular embodiment of the present disclosure should not be construed as a limitation to the particular embodiment of the application or inclusion of said features. Rather, it will be appreciated that other embodiments may also include said features, members, elements, parts, and / or portions without necessarily departing from the scope of the present disclosure.

[0115] Moreover, any feature herein may be combined with any other feature of the same or different embodiments disclosed herein, unless the feature is described as requiring another feature in combination therewith. Moreover, various well-known aspects of the illustrative systems, methods, devices, and the like are not described herein in particular detail so as not to obscure aspects of the exemplary embodiments. However, such aspects are also contemplated herein.

[0116] All references cited in this application are hereby incorporated by reference in their entirety to the extent that they do not contradict the disclosure in this application. It will be apparent to those skilled in the art that methods, devices, device elements, materials, procedures, and techniques other than those specifically described herein can be applied to the practice of the described embodiments as broadly disclosed herein without resorting to undue experimentation. All art-known functional equivalents of the methods, devices, device elements, materials, procedures, and techniques specifically described herein are intended to be encompassed by this disclosure.

[0117] When groups of materials, compositions, components, or compounds are disclosed herein, it is to be understood that all individual members of the group and all subgroups thereof are separately disclosed. When Markush groups or other groupings are used herein, all individual members of the group, and all possible combinations and subcombinations of the group, are intended to be included individually in the disclosure.

[0118] The above-described embodiments are by way of example only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the description, which is defined solely by the claims that follow.

Claims

1. 1. A user equipment (UE) implemented method (400) for moving from a first cell to a second cell, the first cell being a serving cell of the UE and the second cell comprising one of one or more neighbor cells, the method comprising: sending (401) a request to a base station associated with the first cell, while being served in the first cell, to trigger a broadcast of information data in the second cell according to configuration information before moving from the first cell to the second cell; receiving (402) the information data broadcast by a second base station associated with the second cell; The method (400).

2. 2. The method of claim 1, further comprising: calculating at least one of time pre-compensation and frequency pre-compensation to be applied to uplink transmissions in the second cell by using the received information data.

3. receiving a response message approving or denying the request; if the response message is received approving the request, monitoring the information data from a downlink transmission in the second cell; The method (400) of claim 1 or 2, further comprising:

4. The method (400) of any one of claims 1 to 3, wherein said information data comprises satellite ephemeris data broadcast via system information.

5. The method (400) according to any one of claims 1 to 3, further comprising starting a timer governing the period of time during which the UE has to wait until the requested information data is received.

6. If the request is an Msg1-based system information request, one or more preambles are configured for each of the listed set of neighbor cells (10, 20, 40), each of the listed set of satellites (13, 17), and at least one of a set of neighbor cells served by the same satellite (13) or by a different satellite (17); or which of said one or more neighbour cells (10, 20, 40) are served by the same satellite (13) is indicated in said configuration information or by an indicator; or The method (400) according to any one of claims 1 to 5, wherein the one or more neighbour cells (10, 20, 40) served by the same satellite (13) are divided into subgroups in the configuration information or by an indicator.

7. The first cell and the second cell are A cell (10, 20, 30, 40) in a non-terrestrial network (50) using earth moving beams, or Cells (1013a / b / c) in a terrestrial network (1010) and / or The method (400) of any one of claims 1 to 4, wherein the base station and the second base station are the same physical base station.

8. 1. A method (500) implemented by a first network node for moving a user equipment (UE) from a first cell associated with the first network node to a second cell, the first cell being a serving cell for the UE and the second cell comprising one of one or more neighbor cells, the method comprising: receiving (501) in the first cell a request from the UE to trigger a broadcast of information data in the second cell; determining (502) whether the second cell is served by the first network node or by a second network node; forwarding (503) the request for broadcasting of the information data to the second network node if the second cell is served by the second network node; and broadcasting (504) the requested information data in the second cell if the second cell is served by the first network node. The method (500).

9. obtaining configuration information related to a manner in which the UE requests broadcast of the information data in one or more neighbor cells; configuring the UE using broadcasted system information in the first cell with the configuration information related to the technique for requesting broadcast of the information data in the one or more neighbor cells; The method of claim 8, further comprising at least one of:

10. determining whether to accept the request to broadcast the information data in the second cell if the second cell is served by the first network node; receiving, if the second cell is served by the second network node, a response message from the second network node approving or rejecting the request to broadcast the information data in the second cell; 9. The method of claim 8, further comprising any one of:

11. broadcasting the requested information data in the second cell; According to configuration information or the request from the UE, After a delay, At the specified time, one or more times within a time interval, or Repeat several times. The method (500) of any one of claims 8 to 10, comprising broadcasting.

12. 12. The method (500) of any one of claims 8 to 11, wherein broadcasting the requested information data in the second cell comprises broadcasting satellite ephemeris data and at least one of a common timing advance and a common Doppler shift associated with a reference location in the second cell.

13. 1. A method (600) implemented by a second network node for moving a user equipment (UE) from a first cell to a second cell associated with the second network node, the first cell being a serving cell of the UE and controlled by a first network node, the second cell comprising one of one or more neighbor cells of the first cell, the method comprising: receiving (601) a request from said first network node to trigger a broadcast of information data in said second cell; The method (600).

14. broadcasting (602) the requested information data in the second cell; determining whether to accept the request to broadcast the information data in the second cell; and sending a response message to the first network node approving or rejecting the request to broadcast the information data in the second cell; The method of claim 13, further comprising one or more of:

15. A processor (701); A memory (702) storing a computer program which, when executed on said processor, causes said processor to carry out the method according to any one of claims 1 to 7; A user equipment (UE) (700) comprising:

16. A first network node (800), A processor (801); A memory (802) storing a computer program which, when executed on said processor, causes said processor to carry out the method according to any one of claims 8 to 12; A first network node (800).

17. A second network node (900), A processor (901); a memory (902) storing a computer program which, when executed on said processor, causes said processor to carry out the method according to claim 13 or 14; A second network node (900).

18. A computer program product which, when executed on at least one processor, causes said at least one processor to perform the method according to any one of claims 1 to 7.

19. A computer program which, when executed on at least one processor, causes said at least one processor to perform the method according to any one of claims 8 to 12.

20. A computer program which, when executed on at least one processor, causes the at least one processor to perform the method according to claim 13 or 14.

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