Method and apparatus for cell reselection enhancement in wireless communication

Abstract

Various solutions to enhance cell reselection in wireless communications are described. An apparatus receives a configuration from a serving cell and measures the serving cell and neighbor cells based on the configuration. The configuration includes at least one of (i) a first parameter and a second parameter to assist the apparatus in performing an elevation-based cell reselection, (ii) a third parameter indicating a number of beam-hopping synchronization signal blocks (SSBs) to average for cell measurement derivation, (iii) a fourth parameter indicating a threshold for a merging of layer 1 (L1) measurements per beam SSB index, and (iv) a fifth parameter defined as a sum of a received signal power term and a beam distance ratio term each having a corresponding weight factor.

Description

[0001] Cross-references

[0002] This disclosure is part of a non-provisional application that claims priority to PCT application No. PCT / CN2024 / 128510, filed on October 30, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to wireless communications, and more specifically, to cell reselection enhancement in wireless communications (e.g., for non-terrestrial networks (NTN)). Background Technology

[0004] Unless otherwise stated, the methods described in this section are not prior art to the claims and are not considered prior art because they are included in this section.

[0005] In the third-generation partnership program (3 rd In Release 17 of the Generation Partnership Project (3GPP), Non-Terrestrial Networks (NTN) were introduced as a terminal-satellite direct communication technology based on the New Radio (NR) interface. With the integration of satellite networks and terrestrial cellular networks (e.g., 5G...),... th With the convergence of 5G (5G Generation) and 5G networks, NTN enables ubiquitous coverage unrestricted by terrain and topography. As NTN continues to evolve in the 5G-Advanced (5G-A) phase, it has become an important component of the 3GPP Release 18 work plan. Currently, NTN can include two working groups: Internet-of-Things (IoT) NTN and New Radio (NR) NTN. IoT NTN focuses on satellite IoT services supporting low-complexity enhanced machine-type communication (eMTC) user equipment (UE) and narrowband IoT (NB-IoT) UEs. NR NTN adopts the 5G NR framework to enable direct connectivity between satellites and smartphones to provide voice and data services.

[0006] In NTN scenarios, ensuring the overall performance of the communication system is crucial, and cell selection and reselection in idle mode are particularly critical to achieving this goal. Under the current 5G-A NTN framework, UEs use distance-triggered cell reselection based on reference signal received power (RSRP). However, due to the dynamic and unique nature of NTN scenarios, this method may not be sufficient. For example, in NTN scenarios with low signal-to-noise ratios (SNR), the accuracy of the RSRP measured by the UE may be significantly reduced, thus affecting the accuracy of selecting the best satellite or cell based on the measured RSRP. Furthermore, when the UE is mobile, the measured RSRP may fluctuate significantly due to UE movement, which also reduces the accuracy of selecting the best satellite or cell based on the measured RSRP.

[0007] Therefore, it is necessary to provide appropriate solutions to the above problems. Summary of the Invention

[0008] The following summary is for illustrative purposes only and is not intended to be limiting. That is, the following summary aims to introduce the concepts, key points, benefits, and advantages of the novel and non-obvious techniques described herein. Some embodiments will be further described in the detailed description below. Therefore, the following summary is not intended to identify the essential features of the claimed subject matter, nor is it intended to define the scope of the claimed subject matter.

[0009] One objective of this disclosure is to provide schemes, concepts, designs, systems, methods, and apparatuses related to cell reselection enhancement in wireless communications, such as for non-terrestrial networks (NTNs). It is believed that by implementing one or more of the schemes proposed herein, the aforementioned problems can be avoided or mitigated.

[0010] In one aspect, a method may involve receiving a configuration from a serving cell by means of an apparatus, wherein the configuration includes at least one of the following parameters: (i) a first parameter indicating a first reference service elevation angle of the serving cell associated with a first satellite; (ii) a second parameter indicating one or more second reference service elevation angles of one or more neighboring cells associated with one or more second satellites; (iii) a third parameter indicating the number of beam-hopping synchronization signal blocks (SSBs) averaged for cell measurement derivation; (iv) a fourth parameter indicating a threshold for merging Level 1 (L1) measurements for each beam SSB index; and (v) a fifth parameter defined as the sum of a received signal power term and a beam distance ratio term, each having a corresponding weighting factor, wherein the received signal power term is defined as the ratio of SSB received power measured on a set of resource blocks to the carrier received signal strength indication (RSSI), and the beam distance ratio term is defined as the ratio of the distance between the apparatus and the beam center to the beam radius. The method may also involve the apparatus performing measurements on the serving cell and one or more neighboring cells based on the configuration.

[0011] In one aspect, a method may involve a network node forming a serving cell for wireless communication with a device. The method may also involve a network node sending a configuration to the device, wherein the configuration includes at least one of the following parameters: (i) a first parameter and a second parameter for assisting the device in performing elevation-based cell reselection, wherein the first parameter indicates a first reference serving elevation angle of the serving cell associated with a first satellite, and the second parameter indicates one or more second reference serving elevation angles of one or more neighboring cells associated with one or more second satellites; (ii) a third parameter indicating the number of beam-hopping SSBs averaged for cell measurement derivation; (iii) a fourth parameter indicating a threshold for L1 measurement merging for each beam SSB index; and (iv) a fifth parameter defined as the sum of a received signal power term and a beam distance ratio term, each with a corresponding weighting factor, wherein the received signal power term is defined as the ratio of SSB received power measured on a set of resource blocks to the carrier RSSI, and the beam distance ratio term is defined as the ratio of the distance between the device and the beam center to the beam radius.

[0012] In one aspect, an apparatus may include a transceiver that wirelessly communicates with a serving cell and one or more neighboring cells during operation. The apparatus may also include a processor communicatively connected to the transceiver. The processor, during operation, may perform operations including receiving configuration from the serving cell via the transceiver, wherein the configuration includes at least one of the following parameters: (i) a first parameter indicating a first reference service elevation angle of the serving cell associated with a first satellite; (ii) a second parameter indicating one or more second reference service elevation angles of one or more neighboring cells associated with one or more second satellites; (iii) a third parameter indicating the number of beam-hopping SSBs averaged for cell measurement derivation; (iv) a fourth parameter indicating a threshold for L1 measurement merging for each beam SSB index; and (v) a fifth parameter defined as the sum of a received signal power term and a beam distance ratio term, each having a corresponding weighting factor, wherein the received signal power term is defined as the ratio of SSB received power measured on a set of resource blocks to the carrier RSSI, and the beam distance ratio term is defined as the ratio of the distance between the apparatus and the beam center to the beam radius. The processor can also perform operations, including, via transceivers, performing measurements on the serving cell and one or more neighboring cells based on configuration.

[0013] It is worth noting that although the content described herein may be set against the backdrop of certain wireless access technologies, networks, and network topologies, such as Long-Term Evolution (LTE), LTE-Advanced, LTE-AdvancedPro, 5G, 5G-A, NR, Internet of Things (IoT) and Narrowband Internet of Things (NB-IoT), Industrial Internet of Things (IIoT), Beyond 5G (B5G), and 6th Generation (6G), the proposed concepts, schemes, and any variations / derivatives thereof can be implemented, used, and realized in other types of wireless access technologies, networks, and network topologies. Therefore, the scope of this disclosure is not limited to the examples described herein. Attached Figure Description

[0014] The accompanying drawings are included in this specification to further understand this disclosure and form part of this disclosure. The drawings illustrate embodiments of this disclosure and, together with the specification, serve to explain the principles of this disclosure. It will be understood that the drawings are not necessarily drawn to scale, as some components may be shown out of proportion to their actual dimensions for clarity of the concepts of this disclosure.

[0015] Figure 1 The illustration depicts an example scenario of a distance-triggered cell reselection method in the current 5G-A non-terrestrial network (NTN) framework.

[0016] Figure 2 The illustration depicts an example scenario of a cell reselection method based on Reference Signal Received Power (RSRP) in the current 5G-A non-terrestrial network (NTN) framework.

[0017] Figure 3 The diagram illustrates example scenarios of communication environments in which various solutions and schemes of this disclosure can be implemented.

[0018] Figure 4 The illustration depicts an example scenario of the elevation angle between a user equipment (UE) and different satellites according to an embodiment of the present disclosure.

[0019] Figure 5 The illustration depicts an example scenario of cell sorting based on elevation angle according to an embodiment of the present disclosure.

[0020] Figure 6 The illustration depicts an example scenario of multi-beam coverage within an NTN cell according to an embodiment of the present disclosure.

[0021] Figure 7 The diagram illustrates an example communication system according to an embodiment of this disclosure.

[0022] Figure 8 The flowchart illustrates an example process according to an embodiment of this disclosure.

[0023] Figure 9 The flowchart illustrates another example flow according to an embodiment of this disclosure. Detailed Implementation

[0024] This specification discloses detailed embodiments and implementations of the claimed subject matter. However, it should be understood that the disclosed embodiments and implementations are merely illustrative of the claimed subject matter, which can be implemented in various forms. This disclosure can be embodied in many different forms and should not be construed as being limited to the exemplary embodiments and implementations set forth herein. Rather, these exemplary embodiments and implementations are provided to make the description of this disclosure exhaustive and complete, and to fully communicate the scope of this disclosure to those skilled in the art. In the following description, details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the presented embodiments and implementations.

[0025] Overview

[0026] According to embodiments of this disclosure, various techniques, methods, schemes, and / or solutions relate to cell reselection enhancement in wireless communications, such as for non-terrestrial networks (NTNs). According to this disclosure, multiple possible solutions can be implemented individually or in combination. That is, although these possible solutions are described separately below, two or more possible solutions can be implemented in some combination.

[0027] In this disclosure, non-terrestrial networks (NTNs) refer to networks that utilize radio frequency (RF) and information processing resources carried by high-, medium-, and low-Earth orbit satellites or other high-altitude communication platforms to provide communication services to user equipment (UEs). Depending on the payload capabilities of the satellite, there are two typical scenarios: transparent payloads and regenerative payloads. In transparent payload mode, the satellite does not process the signals and waveforms in the communication service; it only acts as an RF amplifier to forward data. In regenerative payload mode, in addition to RF amplification, the satellite also possesses processing capabilities such as modulation / demodulation, encoding / decoding, switching, and routing. It is worth noting that the motivation for this disclosure stems from, but is not limited to, the NTN scenario.

[0028] Currently, in 5G-A New Radio (NR) NTN, to improve mobility in quasi-earth fixed cell scenarios, 3GPP RAN2 has discussed distance-triggered methods / conditions and cell ranking criteria based on Reference Signal Received Power (RSRP). However, distance-triggered methods / conditions may become ineffective or insufficient, and relying solely on RSRP-based cell ranking criteria may lead to high failure rates. Figure 1 Example scenario 100 demonstrates a distance-triggered method for cell reselection within the current 5G-A NTN framework. Scenario 100 describes a scenario where satellites are in regenerative payload mode, in which each satellite, in addition to radio frequency (RF) amplification capabilities, also possesses modulation / demodulation, encoding / decoding, switching, and routing processing capabilities. Figure 1 As shown, when satellite 1 (denoted as SAT#1) is about to stop providing service to the UE's current cell, the distance between the UE and the reference location or reference point of the serving cell (denoted as RP1) is still less than the distance threshold (denoted as distanceThresh) for triggering cell reselection / measurement. Therefore, the UE will only perform cell reselection after detecting that it has left the service of SAT#1, which means that the distance-triggered method is obviously insufficient for NTN in regenerative payload mode.

[0029] Figure 2 This demonstrates 200 example scenarios for cell reselection based on the RSRP method within the current 5G-A NTN framework. For example... Figure 2As shown in Part A, cell measurements for cell reselection are triggered because the distance between the UE and the reference location or reference point of the serving cell (denoted as RP1) is greater than distanceThresh. If power flux density (PFD) constraints are not considered, the UE can perform RSRP-based cell ranking for all neighboring satellites (i.e., SAT#1 to SAT#9). Figure 2 Part B shows the measurement results for RSRP and satellite ID, where SAT#1 and SAT#6 have high RSRP values ​​but limited service duration (because they are about to cease providing service to the UE's area). In other words, reselecting either SAT#1 or SAT#6 will result in a high UE failure rate.

[0030] In view of the above, the motivation of this disclosure stems from, but is not limited to, the NTN scenario, and proposes various schemes related to enhancing cell reselection in wireless communication. Specifically, the schemes proposed in this disclosure introduce innovative methods in the following aspects: (i) cell reselection triggering conditions based on elevation angle, using the satellite elevation angle as a dynamic parameter to trigger cell reselection; (ii) cell ranking criteria based on elevation angle, using elevation angle to determine cell priority and increase the probability of selecting the best available cell; (iii) cell reselection based on beam synchronization signal block (SSB) or distance under multi-beam operation, using the actual distance between the UE and the beam center or the beam SSB between multiple beams to make more informative cell reselection decisions; and (iv) signaling of cell reselection parameters. Thus, by applying the schemes of this disclosure, the efficiency and success rate of cell reselection and measurement processes can be significantly improved.

[0031] Figure 3Example scenario 300 of a communication environment is illustrated, illustrating various solutions and schemes of this disclosure. Scenario 300 involves UE 310 wirelessly communicating with network 320 (e.g., a wireless network including NTN and terrestrial network (TN)) via at least one terrestrial network node 322 (e.g., a base station (BS), such as an evolved Node-B (eNB), next-generation Node-B (gNB), or transmission / reception point (TRP)) and one or more non-terrestrial network nodes 324 (e.g., satellites). In some embodiments, terrestrial network node 322 and non-terrestrial network node 324 can communicate via NTN or satellite gateway (not shown). For example, in transparent payload mode, terrestrial network node 322 and each non-terrestrial network node 324 can form an NTN cell for wireless communication with UE 310. In regenerative payload mode, each non-terrestrial network node 324 can have full / partial gNB functionality and can form an NTN serving cell to wirelessly communicate with UE 310, regardless of whether terrestrial network node 322 is involved. Alternatively, terrestrial network node 322 can form a TN serving cell to wirelessly communicate with UE 310. For example... Figure 3 In the communication environment shown, UE310, terrestrial network node 321, and non-terrestrial network node 322 can implement various schemes related to cell reselection enhancement in wireless communication as described in this disclosure, as follows. It is worth noting that although various proposed schemes may be described separately or individually below, in actual implementation, some or all of the proposed schemes may be used in combination or implemented. Of course, each proposed scheme can also be used or implemented individually.

[0032] Under the first scheme of this disclosure, a cell reselection triggering condition based on elevation angle is proposed. Specifically, when the elevation angle between the user equipment (UE) and the serving satellite is greater than a first threshold (e.g., serviceElevation_S, indicating the serving cell reference service elevation angle for initiating NTN cell measurements based on elevation angle), or less than a second threshold (e.g., 180-serviceElevation_S), it means that the serving satellite is about to cease providing service to the serving cell (i.e., the area where the UE is located). Therefore, the UE can perform cell reselection measurements at the same frequency and / or different frequencies. The elevation angle between the UE and the satellite can be calculated by the UE as the angle between the horizontal vector of the satellite's direction of movement and the satellite vector pointing towards the UE.

[0033] Figure 4 An example scenario 400 is shown, illustrating the elevation angle between the UE and different satellites according to an embodiment of this disclosure. Figure 4 Part (A) describes the situation where the satellite is moving towards the left / west of the UE, while Figure 4 Part (B) describes the situation where the satellite moves toward the right / east of the UE.

[0034] In some embodiments, the UE may use the following rules in Table 1 to limit the required measurements.

[0035]

[0036] Table 1

[0037] In some embodiments, when evaluating S during a reselection assessment of a non-serving cell... rxlev and S qual When the UE is in the cell selection process, it can use the parameters provided by the serving cell; while during the final cell selection criterion check, the UE can use the parameters provided by the target cell for cell reselection.

[0038] Under the second scheme of this disclosure, a cell ranking standard based on elevation angle is proposed. Specifically, the cell ranking based on elevation angle takes the elevation angle of the serving satellite and neighboring satellites as the key factor in cell ranking, so that the best-ranked cell corresponds to the satellite with the longer service duration.

[0039] In the first phase of cell selection based on elevation angle, for cases where threshServingLowQ is broadcast in system information (e.g., System Information Block (SIB)) and the UE camps on the current serving cell for more than X seconds, if the high-priority NR or EUTRAN RAT / frequency cell is in the Treselection time interval... RAT Internally satisfying S qual Thresh X, HighQ If so, cell reselection can be performed to a cell with a higher priority NR frequency or a different RAT / frequency relative to the serving frequency. Otherwise, if: (i) the cell with the higher priority RAT / frequency is selected within the Treselection time interval... RAT Internally satisfying S rxlev Thresh X, HighP(ii) If the UE remains in the current serving cell for more than 1 second, cell reselection can be performed to a cell with a higher priority NR frequency or a different RAT frequency relative to the serving frequency. For cell reselection of NR frequencies with equal priority, the reselection order of intra-frequency cells as defined in Clause 5.2.4.6 of 3GPP Technical Specification (TS) 38.331 can be used. In the case where the system information broadcasts threshServingLowQ and the UE remains in the current serving cell for more than 1 second, if the serving cell meets the S... qual Thresh Serving, LowQ Furthermore, cells with low priority NR or E-UTRAN RAT / frequency have a time interval Treselection RAT Internally satisfying S qual Thresh X, LowQ If so, cell reselection can be performed to a cell with a lower priority NR frequency or a different RAT frequency relative to the serving frequency. Otherwise, if: (i) the serving cell satisfies S rxlev <Thresh Serving, LowP, Furthermore, cells with low priority RAT / frequency have a Treselection time interval. RAT Internally satisfying S rxlev Thresh X, LowP (ii) If the UE remains camped on the current serving cell for more than 1 second, a cell reselection can be performed to a cell with a lower priority NR frequency or a different RAT frequency relative to the serving frequency. If multiple cells with different priorities meet the cell reselection criteria, the cell reselection of the higher priority RAT / frequency can take precedence over the cell reselection of the lower priority RAT / frequency.

[0040] In the second phase of elevation-based cell ranking, if multiple cells meet the above conditions in the first phase, the User Equipment (UE) can reselect the serving cell (Rs) and neighboring cells (Rn) according to the following cell ranking criteria. If serviceElevation is broadcast in System Information Block 19 (SIB19) or Non-Terrestrial Network System Information Block (NTN_SIB), and the UE supports elevation-based measurements of NTN cells and has obtained their location information and satellite ephemeris information, the UE can calculate Rs (via Rs = 180 + serviceElevation_S – Es) and Rn (via Rn = 180 + serviceElevation_N – En). Otherwise, the UE can calculate Rs (via Rs = Q meas,s +Q hyst –Qoffset temp ) and Rn (via Rn = Q meas,n-Qoffset –Qoffset temp The UE can sort all cells that meet the cell selection criterion S. Cells can be sorted according to the R criterion mentioned above, and the UE can perform cell reselection to the highest-ranked cell. In all cases, the UE can only reselect a new cell if the following conditions are met: (i) within the Treselection time interval. RAT Within (ii) according to the above cell reselection criteria, the new cell is preferred over the serving cell; and (ii) more than X seconds have passed since the UE has been camped on the current serving cell.

[0041] The definitions of the parameters used in cell ranking based on elevation angle are shown in Table 2 below.

[0042]

[0043] Table 2

[0044] Figure 5 An example scenario 500 of cell ranking based on elevation angle is shown in an embodiment of this disclosure. For example... Figure 5 As shown in section (A), cell measurements for cell reselection are triggered because the distance between the UE and the reference location or reference point of the serving cell (denoted as RP1) is greater than distanceThresh. If PFD constraints are not considered, the UE can perform cell sorting based on elevation angle for all satellites (i.e., SAT#1 to SAT#9). Figure 5 Part (B) shows the measurements related to the Reference Signal Received Power (RSRP) and Satellite ID, where SAT#5 and SAT#9 have the lowest elevation angles (i.e., the longest or longest service duration among all satellites). This means that reselecting to SAT#5 or SAT#9 will have an extremely low failure rate compared to other satellites.

[0045] Under the third scheme of this disclosure, a cell reselection method based on beam synchronization signal blocks (SSBs) in multi-beam operation is proposed. For beam-hopping cell reselection in NTN systems, including inter-RAT reselection, the number of cell measurements can be derived between beams corresponding to the same cell based on the beam-hopping SSBs as follows. If numofBeamSS-BlocksToAverage is not configured for cell reselection in the System Information Block (SIB), or absThreshBeamSS-BlocksConsolidation is not configured for cell reselection in the System Information Block (SIB), or the highest beam measurement count is less than or equal to absThreshBeamSS-BlocksConsolidation, then the UE can derive the cell measurement count as the highest beam-hopping SSB measurement count. Otherwise, if none of the above three conditions are met, the UE can derive the number of cell measurements as a linear average of the power values ​​of at most nrofBeamSS-BlocksToAverage, which are higher than the number of beam measurements above absThreshBeamSS-BlocksConsolidation. It should be noted that when considering beam hopping in the NTN, different thresholds can be configured for different beam SSBs, as different beam coverage may result in different beamwidths and satellite antenna gains.

[0046] The parameters used in the beam-based SSB cell reselection are defined as shown in Table 3 below.

[0047]

[0048] Table 3

[0049] Under the fourth scheme of this disclosure, a distance-based cell reselection method in multi-beam operation is proposed. For beam-hopping cell reselection in NTN systems, including inter-RAT reselection, the distance-based measurement count of the cell can be derived between beams corresponding to the same cell based on the beam-hopping SSB as follows: If numofBeamSS-BlocksToAverage is not configured for cell reselection in the System Information Block (SIB), or absThreshBeamSS-BlocksConsolidation is not configured for cell reselection in the System Information Block (SIB), or the highest beam measurement count is less than or equal to absThreshBeamSS-BlocksConsolidation, then the UE can derive the cell distance-based measurement count as the highest beam-hopping SS / PBCH block distance-based measurement count, where the distance-based measurement count for each beam is equal to SS-RSRQ_D. Otherwise, if none of the above three conditions are met, the UE can derive the cell distance-based measurement count as (factor_RSRP) average_RSRP) and (factor_D The sum of the ratios of DistanceToBeamcentre and BeamRadius, where average_RSRP is the linear average of the power values ​​of the highest number of beam measurements above absThreshBeamSS-BlocksToAverage, DistanceToBeamcentre is the absolute distance from the UE to the beam hop center responsible for beam hop indexing, and BeamRadius is the absolute beam radius responsible for beam hop indexing. Note that when considering beam hops in the NTN, the UE can prioritize the RSRP value of the nearest beam and reduce the priority of the RSRP value of the farthest beam, such as... Figure 6 As shown.

[0050] Under the fifth scheme of this disclosure, signaling for cell reselection parameters is proposed. Specifically, the cell reselection parameters include at least the aforementioned numofBeamSS-BlocksToAverage, absThreshBeamSS-BlocksConsolidation, SS-RSRQ_D, serviceElevation_S, and serviceElevation_N, which can be broadcast in system information (e.g., system information block (SIB) 19 / 32 or others) and can be read from the serving cell.

[0051] Example Implementation

[0052] Figure 7 An example communication system 700 according to an embodiment of this disclosure is shown, having an example communication device 710 and an example network device 720. Both the communication device 710 and the network device 720 can perform various functions to implement the schemes, techniques, processes and methods described herein, relating to enhancements in cell reselection in wireless communication, including the scenarios / schemes described above and processes 800 and 900 described below.

[0053] The communication device 710 can be part of an electronic device, which can be user equipment (UE), such as a portable or mobile device, wearable device, wireless communication device, or computing device. For example, the communication device 710 can be implemented in a smartphone, smartwatch, personal digital assistant, electronic control unit (ECU) in a vehicle, digital camera, or computing device such as a tablet, laptop, or mobile phone. The communication device 710 can also be part of a machine-type device, which can be an Internet of Things (IoT), narrowband Internet of Things (NB-IoT), industrial Internet of Things (IIoT), Bluetooth Low Energy (BL), or consumer electronics user equipment (CE UE), such as immovable or fixed devices, home devices, roadside units (RSUs), wired communication devices, or computing devices. For example, the communication device 710 can be implemented in a smart thermostat, smart refrigerator, smart door lock, wireless speaker, or home control center. Alternatively, the communication device 710 may be implemented as one or more integrated circuit (IC) chips, such as, but not limited to, one or more single-core processors, one or more multi-core processors, one or more reduced-instruction-set computing (RISC) processors, or one or more complex-instruction-set computing (CISC) processors. The communication device 710 may include... Figure 7 The communication device 710 may include at least some of the components shown, such as processor 712. It may also include one or more other components unrelated to this disclosure (e.g., internal power supply, display device, and / or user interface device), and thus, such components of the communication device 710 are... Figure 7 This is not shown in the text and is not described below, in order to simplify and refine the content.

[0054] Network device 720 may be part of an electronic device, which may be a network node such as a satellite, base station (BS), cell, router, or gateway of a non-terrestrial network (NTN). For example, network device 720 may be implemented in an evolved NB, next-generation NB, or transport access point (TRP) in a satellite and / or 4G / 5G, NR, IoT, NB-IoT, or IIoT network. Alternatively, network device 720 may be implemented as one or more IC chips, such as, but not limited to, one or more single-core processors, one or more multi-core processors, or one or more RISC or CISC processors. Network device 720 may include... Figure 7 The network device 720 may include at least some of the components shown, such as processor 722. It may also include one or more other components unrelated to this disclosure (e.g., internal power supply, display device, and / or user interface device), and thus, such components of the network device 720 are... Figure 7 This is not shown in the text and is not described below, in order to simplify and refine the content.

[0055] In one aspect, both processor 712 and processor 722 may be implemented as one or more single-core processors, one or more multi-core processors, or one or more CISC processors. That is, although the singular term "processor" is used herein to refer to processor 712 and processor 722, processor 712 and processor 722 may include multiple processors according to certain embodiments of this disclosure, and may include a single processor in other embodiments. In another aspect, both processor 712 and processor 722 may be implemented as hardware (and optionally firmware) whose electronic components include, but are not limited to, one or more transistors, one or more diodes, one or more capacitors, one or more resistors, one or more inductors, one or more memristors, and / or one or more transformers, configured and arranged according to this disclosure to achieve a particular purpose. In other words, in at least some embodiments, processor 712 and processor 722 are dedicated machines specifically designed, arranged, and configured to perform specific tasks in devices (e.g., represented by communication device 710) and network nodes (e.g., represented by network device 720), including inter-satellite measurements and handover in non-terrestrial networks (NTNs), consistent with various embodiments of this disclosure.

[0056] In some embodiments, the communication device 710 may further include a transceiver 716 connected to the processor 712, capable of wirelessly transmitting and receiving data. In some embodiments, the transceiver 716 is capable of wireless communication with wireless networks of different types of user equipment (UEs) and / or different radio access technologies (RATs). In some embodiments, the transceiver 716 may be equipped with multiple antenna ports (not shown), such as four antenna ports. That is, the transceiver 716 may be equipped with multiple transmit antennas and multiple receive antennas for multiple-input multiple-output (MIMO) wireless communication. In some embodiments, if a mechanically directional antenna is used, the transceiver 716 may be equipped with a rotor. Alternatively, if an electronically directional antenna is used, the transceiver 716 may be equipped with a phased array antenna. In some embodiments, the network device 720 may further include a transceiver 726 connected to the processor 722. The transceiver 726 may include a transceiver capable of wirelessly transmitting and receiving data. In some embodiments, the transceiver 726 is capable of wireless communication with different types of UEs using different RATs. In some implementations, transceiver 726 may be equipped with multiple antenna ports (not shown), such as four antenna ports. That is, transceiver 726 may be equipped with multiple transmit antennas and multiple receive antennas for MIMO wireless communication.

[0057] In some embodiments, the communication device 710 may further include a memory 714 connected to and accessible by the processor 712, and storing data therein. In some embodiments, the network device 720 may further include a memory 724 connected to and accessible by the processor 722, and storing data therein. Each of the memories 714 and 724 may include a random-access memory (RAM), such as dynamic RAM (DRAM), static RAM (SRAM), thyristor RAM (T-RAM), and / or zero-capacitor RAM (Z-RAM). Alternatively, or additionally, each of the memories 714 and 724 may include a read-only memory (ROM), such as a mask ROM, a programmable ROM (PROM), an erasable programmable ROM (EPROM), and / or an electrically erasable programmable ROM (EEPROM). Alternatively, each of the memories 714 and 724 may include a non-volatile random access memory (NVRAM), such as flash memory, solid-state memory, ferroelectric RAM (FeRAM), magnetoresistive RAM (MRAM), and / or phase-change memory.

[0058] Each of the communication device 710 and the network device 720 can be a communication entity capable of communicating with each other according to various proposed schemes of this disclosure. For illustrative purposes only and without limitation, the capabilities of the communication device 710 as a user equipment (UE) and the network device 720 as a network node (e.g., a satellite and / or base station (BS)) are described below in conjunction with procedures 800 and 900.

[0059] Example Process

[0060] Figure 8The example illustrates an example flow 800 according to an embodiment of this disclosure. Flow 800 can serve as an example implementation of the above-described scenario / solution, whether partially or entirely, for enhancements to cell reselection in wireless communication. Flow 800 can represent one aspect of the functional implementation of communication device 710. Flow 800 may include one or more operations, actions, or functions, as shown in one or more modules 810 to 840. Although represented as discrete modules, the modules of flow 800 may be divided into more modules, merged into fewer modules, or omitted depending on the desired implementation. Furthermore, the modules of flow 800 may be arranged in... Figure 8 The process is executed in the order shown, or in a different order. Process 800 can be implemented by communication device 710 or any suitable user equipment (UE). For illustrative purposes only and without limitation, process 800 is described below in the context of communication device 710 as a UE. Process 800 may begin with module 810.

[0061] At 810, process 800 may involve the processor 712 of communication device 710 receiving configuration from a serving cell via transceiver 716, wherein the configuration includes at least one of the following parameters: (i) a first parameter indicating a first reference service elevation angle of the serving cell associated with a first satellite (e.g., network device 720); (ii) a second parameter indicating one or more second reference service elevation angles of one or more neighboring cells associated with one or more second satellites; (iii) a third parameter indicating the number of beam-hopping synchronization signal blocks (SSBs) averaged for cell measurement derivation; (iv) a fourth parameter indicating a threshold for merging Level 1 (L1) measurements for each beam SSB index; and (v) a fifth parameter defined as the sum of a received signal power term and a beam distance ratio term, each with a corresponding weighting factor, wherein the received signal power term is defined as the ratio of SSB received power measured on a set of resource blocks to the carrier received signal strength indication (RSSI), and the beam distance ratio term is defined as the ratio of the distance between the device and the beam center to the beam radius. Process 800 may proceed from 810 to 820.

[0062] In 820, process 800 may involve processor 712 performing measurements on the serving cell and one or more neighboring cells based on configuration via transceiver 716.

[0063] In some implementations, when the first parameter and the second parameter are configured, measurements can be performed on the serving cell and one or more neighboring cells based on the first elevation angle between the device and the first satellite and the first reference service elevation angle. The process 800 may also involve the processor 712 determining an elevation angle-based cell ranking for at least one of the selected one or more neighboring cells and the serving cell based on the measurement results, and performing cell reselection to the cell ranked highest in the elevation angle-based cell ranking.

[0064] In some implementations, cell sorting based on elevation angle can be determined based on a first reference service elevation angle, a first elevation angle, one or more second reference service elevation angles, and one or more second elevation angles between the communication device 710 and one or more second satellites.

[0065] In some embodiments, the first elevation angle may be calculated as a first angle between the horizontal vector of the satellite's direction of movement and a first vector pointing to the first satellite of the communication device 710, and each or more second elevation angles may be calculated as a second angle between the horizontal vector of the satellite's direction of movement and a second vector pointing to one of the one or more second satellites of the communication device 710.

[0066] In some implementations, measurements may be performed on the serving cell and one or more neighboring cells if the first elevation angle is greater than or less than the value obtained by subtracting the first reference service elevation angle from 180. Furthermore, process 800 may also involve the processor 712 determining that measurements should not be performed on the serving cell and one or more neighboring cells if the first elevation angle is not greater than or less than the value obtained by subtracting the first reference service elevation angle from 180.

[0067] In some implementations, the measurement results may include the number of cell measurements for each serving cell and one or more neighboring cells that support multi-beam operation, and the number of cell measurements may be derived as the number of highest beam-hopping synchronization signal blocks (SSBs) measurements, or as a linear average of the power values ​​of up to X highest beam measurements exceeding Y, where X is defined as a third parameter indicating the number of beam-hopping SSBs averaged for cell measurement derivation, and Y is defined as a fourth parameter indicating the threshold for merging Level 1 (L1) measurements for each beam SSB index.

[0068] In some implementations, when X or Y is not configured or the number of highest beam-hopping SSB measurements is less than or equal to Y, the number of cell measurements can be derived from the number of highest beam-hopping SSB measurements. Alternatively, when X and Y are configured and the number of highest beam-hopping SSB measurements is greater than Y, the number of cell measurements can be derived from the linear average of the power values ​​of up to X highest beam measurements exceeding Y.

[0069] In some implementations, the measurement results may include the number of cell measurements for each serving cell and one or more neighboring cells that support multi-beam operation, and the number of cell measurements may be derived as the number of highest beam-hopping SSB measurements, with the number of SSB measurements for each beam-hopping cell equal to the fifth parameter.

[0070] In some implementations, the received signal power term can be defined as the ratio of the SSB received power measured on a set of resource blocks to the carrier RSSI. Additionally, or optionally, the beam distance ratio term can be defined as the ratio of the distance between the communication device 710 and the beam center to the beam radius. Furthermore, or optionally, the corresponding weighting factors can be predefined or configured in the System Information Block (SIB).

[0071] In some implementations, the number of cell measurements can be derived when the third or fourth parameter is not configured or the number of highest beam hopping SSB measurements is less than or equal to the fifth parameter.

[0072] In some implementations, the measurement results may include the number of cell measurements for each serving cell and one or more neighboring cells that support multi-beam operation, and the number of cell measurements may be derived as the sum of the average received signal power and the beam distance ratio, each with a corresponding weighting factor.

[0073] In some implementations, the average received signal power may include a linear average of power values ​​from up to X the highest number of beam measurements exceeding Y, where X represents the number of beam-hopping SSBs averaged for cell measurement derivation, and Y represents the threshold for combining L1 measurements for each beam SSB index. Additionally, or optionally, the beam distance ratio term may be defined as the ratio of the distance between the communication device 710 and the beam center to the beam radius. Furthermore, or optionally, the corresponding weighting factors may be predefined or configured in the System Information Block (SIB).

[0074] In some implementations, the number of cell measurements can be derived when the third and fourth parameters are configured and the number of highest beam hopping SSB measurements is greater than the fourth parameter.

[0075] In some implementations, configuration may be received in the System Information Block (SIB).

[0076] Figure 9 An example flow 900 under another embodiment of this disclosure is illustrated. Flow 900 can serve as an example implementation of the above-described scenario / solution, whether partially or entirely, for cell reselection enhancement in wireless communication. Flow 900 can represent one aspect of a characteristic implementation of network device 720. Flow 900 may include one or more operations, actions, or functions as shown in blocks 910 and 920. Although shown in discrete blocks, the individual blocks of flow 900 may be divided into more blocks, merged into fewer blocks, or omitted depending on the desired implementation. Furthermore, the individual blocks of flow 900 may be arranged in... Figure 9The process 900 may be executed in the order shown, or in a different order. Process 900 may be implemented by network device 720 or any variant thereof. For illustrative purposes only and without limitation, process 900 is described below with the communication device 710 (as a UE) and network device 720 (as a network node, such as a satellite and / or base station (BS)) in the context of these two devices. Process 900 may begin with block 910.

[0077] In 910, process 900 may involve the processor 722 of network device 720 forming a serving cell via transceiver 726 to wirelessly communicate with communication device 710. Process 900 may proceed from block 910 to block 920.

[0078] At 920, process 900 may involve processor 722 sending a configuration to communication device 710 via transceiver 726, wherein the configuration includes at least one of the following parameters: (i) a first parameter and a second parameter for assisting the device in performing elevation-based cell reselection, wherein the first parameter indicates a first reference service elevation angle of the serving cell associated with a first satellite, and the second parameter indicates one or more second reference service elevation angles of one or more neighboring cells associated with one or more second satellites; (ii) a third parameter indicating the number of beam-hopping SSBs averaged for cell measurement derivation; (iii) a fourth parameter indicating a threshold for L1 measurement merging for each beam SSB index; and (iv) a fifth parameter defined as the sum of a received signal power term and a beam distance ratio term, each with a corresponding weighting factor, wherein the received signal power term is defined as the ratio of SSB received power measured on a set of resource blocks to the carrier RSSI, and the beam distance ratio term is defined as the ratio of the distance between the device and the beam center to the beam radius.

[0079] In some implementations, configuration may be received in the System Information Block (SIB).

[0080] Additional Notes

[0081] The topics described in this specification sometimes show different components contained in or connected to other different components. It should be understood that such illustrated architectures are merely examples, and many other architectures can actually be implemented to achieve the same functionality. Conceptually, any arrangement of components to achieve the same functionality is effectively “associated” to achieve the desired function. Therefore, any two components combined herein to achieve a particular function can be considered “associated with each other” to achieve the desired function, regardless of the architecture or intermediate components. Similarly, any two such associated components can also be considered “operationally connected” or “operationally coupled” to achieve the desired function, and any two components that can be suchly associated can also be considered “operationally coupled” to achieve the desired function. Specific examples of operational coupling include, but are not limited to, physically matable and / or physically interactive components and / or wirelessly interactive components and / or logically interactive and / or logically interactive components.

[0082] Furthermore, regarding the use of almost all plural and / or singular terms in this document, those skilled in the art can appropriately convert plural to singular and / or singular to plural depending on the context and / or application. Various singular / plural arrangements are explicitly listed herein for clarity.

[0083] Furthermore, those skilled in the art will understand that the terms commonly used herein, particularly in appended claims, such as the body portion of appended claims, are generally intended as “open” terms. For example, “comprising” should be interpreted as “including but not limited to,” “having” should be interpreted as “having at least,” and “including” should be interpreted as “including but not limited to,” etc. Those skilled in the art will also understand that if a specific number of claim elements is explicitly expressed in the claim, then that intention is explicitly expressed in the claim; if not, then there is no such intention. For example, for ease of understanding, appended claims may include the introductory phrases “at least one” and “one or more” to introduce claim elements. However, the use of such phrases should not be construed as limiting any particular claim containing that element to containing only one of that element by introducing the claim element with the indefinite article “a” or “an,” even if the same claim contains the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an,” for example, “a” and / or “an” should be interpreted as “at least one” or “one or more”; the same applies to definite articles used to introduce claim elements. Furthermore, even when a specific number of elements incorporating a claim is explicitly stated, those skilled in the art will recognize that the expression should be interpreted as at least the stated number. For example, expressing "two elements" without any other modifiers indicates at least two elements, or two or more elements. Additionally, when using conventions such as "at least one A, B, and C, etc.", this structure is generally intended to be interpreted in a manner understood by those skilled in the art. For example, "a system having at least one A, B, and C" includes, but is not limited to, systems with only A, only B, only C, A and B, A and C, B and C, and systems with A, B, and C. Similarly, when using conventions such as "at least one A, B, or C, etc.", this structure is generally intended to be interpreted in a manner understood by those skilled in the art. For example, "a system having at least one A, B, or C" includes, but is not limited to, systems with only A, only B, only C, A and B, A and C, B and C, and systems with A, B, and C. Those skilled in the art will further understand that almost all extractives and / or phrases presenting two or more alternative terms in the specification, claims, or drawings should be understood to include one, any, or both terms. For example, "A or B" should be understood as including the possibility of "A" or "B" or "A and B".

[0084] As can be seen from the foregoing, various embodiments of this disclosure have been described herein for illustrative purposes, and various modifications can be made without departing from the scope and spirit of this disclosure. Therefore, the various embodiments disclosed herein are not intended to be limiting, and the true scope and spirit are indicated by the claims.

Claims

1. A method comprising: The processor of the device receives a configuration from the serving cell, wherein the configuration includes at least one of the following parameters: The first parameter indicates the first reference service elevation angle of the serving cell associated with the first satellite; The second parameter indicates one or more second reference service elevation angles of one or more neighboring cells associated with one or more second satellites; The third parameter indicates the number of beam-jump synchronization signal blocks averaged for cell measurement derivation; The fourth parameter indicates the threshold for merging the first-level measurements for each beam synchronization signal block index; and The fifth parameter is defined as the sum of the received signal power term and the beam distance ratio term, each with its corresponding weighting factor. The received signal power term is defined as the ratio of the received power of the synchronization signal block measured on a set of resource blocks to the carrier received signal strength indication, and the beam distance ratio term is defined as the ratio of the distance between the device and the beam center to the beam radius. The processor performs measurements on the serving cell and the one or more neighboring cells based on the configuration.

2. The method of claim 1, wherein, With the first parameter and the second parameter configured, the measurement is performed on the serving cell and the one or more neighboring cells based on the first elevation angle between the device and the first satellite and the first reference service elevation angle, and the method further includes: Based on the measurement results, the processor determines an elevation-based cell ranking for at least one of the selected neighboring cells and the serving cell; and The processor performs cell reselection to the highest-ranked cell in the elevation-based cell ranking.

3. The method of claim 2, wherein, The elevation-based cell ranking is determined based on the first reference service elevation angle, the first elevation angle, the one or more second reference service elevation angles, and the one or more second elevation angles between the device and the one or more second satellites.

4. The method of claim 3, wherein, The first elevation angle is calculated as a first angle between the horizontal vector of the satellite's direction of movement and a first vector pointing to the first satellite of the device, and each of the one or more second elevation angles is calculated as a second angle between the horizontal vector of the satellite's direction of movement and a second vector pointing to one of the one or more second satellites of the device.

5. The method of claim 2, wherein, If the first elevation angle is greater than the first reference service elevation angle or less than the value obtained by subtracting the first reference service elevation angle from 180, the measurement is performed on the serving cell and the one or more neighboring cells, and the method further includes: If the first elevation angle is not greater than the first reference service elevation angle or not less than the value obtained by subtracting the first reference service elevation angle from 180, the processor determines that the measurement should not be performed on the serving cell and the one or more neighboring cells.

6. The method of claim 1, wherein, The measurement results include the number of cell measurements for each serving cell and one or more neighboring cells that support multi-beam operation, and the number of cell measurements is derived as the number of highest beam-hopping synchronization signal block measurements, or as a linear average of the power values ​​of up to X highest beam measurements exceeding Y, where X is defined as a third parameter indicating the number of beam-hopping SSBs to be averaged for cell measurement derivation, and Y is defined as a fourth parameter indicating the threshold for merging Layer 1 (L1) measurements for each beam SSB index.

7. The method of claim 6, wherein, If X or Y is not configured or the number of measurements of the highest beam hopping synchronization signal block is less than or equal to Y, the number of measurements of the cell is derived as the number of measurements of the highest beam hopping synchronization signal block; or if X and Y are configured and the number of measurements of the highest beam hopping synchronization signal block is greater than Y, the number of measurements of the cell is derived as the linear average of the power values ​​of at most X highest beam measurements exceeding Y.

8. The method of claim 1, wherein, The measurement results include the number of cell measurements for each serving cell and one or more neighboring cells that support multi-beam operation, and the number of cell measurements is derived from the number of measurements for the highest beam-jump synchronization signal block, with the number of measurements for each beam-jump synchronization signal block equal to the fifth parameter.

9. The method of claim 8, wherein: The received signal power term is defined as the ratio of the received power of the synchronization signal block measured on a set of resource blocks to the carrier received signal strength indication; The beam distance ratio is defined as the ratio of the distance between the device and the beam center to the beam radius; as well as The corresponding weighting factor is predefined or configured in the system information block.

10. The method of claim 8, wherein, If the third or fourth parameter is not configured, or if the number of measurements of the highest beam-jump synchronization signal block is less than or equal to the fifth parameter, the number of measurements of the cell is derived.

11. The method of claim 1, wherein, The measurement results include the number of cell measurements for each serving cell and one or more neighboring cells that support multi-beam operation, and the number of cell measurements is derived as the sum of the average received signal power and the beam distance ratio, each with a corresponding weighting factor.

12. The method of claim 11, wherein: The average received signal power includes a linear average of the power values ​​of up to X highest beam measurement counts exceeding Y, where X represents the average number of beam-hopping SSBs used for cell measurement derivation, and Y represents the threshold for combining L1 measurements for each beam SSB index. The beam distance ratio is defined as the ratio of the distance between the device and the beam center to the beam radius; and The corresponding weighting factor is predefined or configured in the system information block.

13. The method of claim 11, wherein, When the third and fourth parameters are configured and the number of measurements of the highest beam-jump synchronization signal block is greater than the fourth parameter, the number of measurements of the cell is derived.

14. The method of claim 1, wherein, This configuration is received in the system information block.

15. A method comprising: The processor of the network node forms a serving cell to communicate wirelessly with the device; as well as The processor sends a configuration to the device, wherein the configuration includes at least one of the following parameters: The first parameter and the second parameter are used to assist the device in performing cell reselection based on elevation angle, wherein the first parameter indicates the first reference service elevation angle of the serving cell associated with the first satellite, and the second parameter indicates one or more second reference service elevation angles of one or more neighboring cells associated with one or more second satellites. The third parameter indicates the number of beam-jump synchronization signal blocks averaged for cell measurement derivation; The fourth parameter indicates the threshold for merging the first-level measurements for each beam synchronization signal block index; and The fifth parameter is defined as the sum of the received signal power term and the beam distance ratio term, each with its corresponding weighting factor. The received signal power term is defined as the ratio of the received power of the synchronization signal block measured on a set of resource blocks to the carrier received signal strength indication, and the beam distance ratio term is defined as the ratio of the distance between the device and the beam center to the beam radius.

16. The method of claim 15, wherein, This configuration is received in the system information block.

17. An apparatus comprising: A transceiver that communicates wirelessly with the serving cell and one or more neighboring cells during operation; as well as A processor, communicatively connected to the transceiver, enables the processor to perform operations during operation including: The transceiver receives a configuration from the serving cell, wherein the configuration includes at least one of the following parameters: The first parameter indicates the first reference service elevation angle of the serving cell associated with the first satellite; The second parameter indicates one or more second reference service elevation angles of the one or more neighboring cells associated with one or more second satellites; The third parameter indicates the number of beam-jump synchronization signal blocks averaged for cell measurement derivation; The fourth parameter indicates the merging threshold for the first-level measurements of each beam synchronization signal block index; and The fifth parameter is defined as the sum of the received signal power term and the beam distance ratio term, each with its corresponding weighting factor. The received signal power term is defined as the ratio of the received power of the synchronization signal block measured on a set of resource blocks to the carrier received signal strength indication, and the beam distance ratio term is defined as the ratio of the distance between the device and the beam center to the beam radius. Measurements are performed on the serving cell and the one or more neighboring cells based on the configuration using this transceiver.

18. The apparatus of claim 17, wherein, With the first parameter and the second parameter configured, the measurement is performed on the serving cell and the one or more neighboring cells based on the first elevation angle between the device and the first satellite and the first reference service elevation angle, and the processor further performs operations during operation including: Based on the results of this measurement, a cell ranking based on elevation angle is determined for at least one of the selected neighboring cells and the serving cell; and Perform a cell reselection to the highest-ranked cell in the cell ranking based on elevation angle.

19. The apparatus of claim 18, wherein: The elevation angle-based cell ranking is determined based on the first reference service elevation angle, the first elevation angle, the one or more second reference service elevation angles, and the one or more second elevation angles between the device and the one or more second satellites; The first elevation angle is calculated as a first angle between the horizontal vector of the satellite's direction of movement and a first vector pointing towards the first satellite of the device; as well as Each of the one or more second elevation angles is calculated as a second angle between the horizontal vector of the satellite's direction of movement and a second vector pointing to one of the one or more second satellites of the device.

20. The apparatus of claim 18, wherein, If the first elevation angle is greater than the first reference serving elevation angle or less than the value obtained by subtracting the first reference serving elevation angle from 180, the measurement is performed on the serving cell and the one or more neighboring cells, and the processor further performs the following operations during operation: If the first elevation angle is not greater than the first reference service elevation angle or not less than the value obtained by subtracting the first reference service elevation angle from 180, it is determined that the measurement will not be performed on the serving cell and the one or more neighboring cells.

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