Method, device, equipment, medium and product for adjusting mobile strategy of low-altitude terminal

Abstract

The application discloses a low-altitude terminal mobile strategy adjustment method, device, equipment, medium and product, and terminal types of terminals are identified; wherein, the terminal types are low-altitude terminals or non-low-altitude terminals; when the terminal is a low-altitude terminal, a low-altitude mobility strategy is configured for the low-altitude terminal; when the terminal is a non-low-altitude terminal, a ground mobility strategy is configured for the non-low-altitude terminal. By means of the application, a suitable low-altitude mobility strategy can be configured for the low-altitude terminal, and communication quality of the low-altitude terminal is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a method, apparatus, device, medium, and product for adjusting the mobility strategy of a low-altitude terminal. Background Technology

[0002] The low-altitude economy has huge potential for development. It mainly refers to a comprehensive economic model that relies on low-altitude airspace, is driven by the low-altitude flight activities of various manned and unmanned aircraft, and radiates and promotes the integrated development of related fields.

[0003] Since the low-altitude economy is in its initial stage, the existing 5G wireless network has not yet undergone special adjustments and optimizations for low-altitude terminals. Therefore, low-altitude terminals still rely on the original ground mobility strategy during flight. That is, the terminals still complete mobility handover based on the same frequency handover and different frequency handover strategies after measurement. This leads to chaotic low-altitude handover in the current network, with low-altitude terminals frequently handing over during flight. The handover sequence is unstable, and there are differences in the test results of different tests on the same line. In addition, low-altitude terminals receive a large number of cell signals in the air, resulting in significant interference. Summary of the Invention

[0004] The purpose of this invention is to provide a method, apparatus, device, medium, and product for adjusting the mobility strategy of a low-altitude terminal, which can configure a suitable low-altitude mobility strategy for the low-altitude terminal and ensure the communication quality of the low-altitude terminal.

[0005] To achieve the above objectives, embodiments of the present invention provide a method for adjusting the mobility strategy of a low-altitude terminal, comprising:

[0006] Identify the terminal type; wherein the terminal type is a low-altitude terminal or a non-low-altitude terminal;

[0007] When the terminal is a low-altitude terminal, a low-altitude mobility strategy is configured for the low-altitude terminal.

[0008] When the terminal is a non-low-altitude terminal, a ground mobility strategy is configured for the non-low-altitude terminal.

[0009] As an improvement to the above solution, the identification of the terminal type is specifically as follows:

[0010] The terminal type is determined based on the terminal's slice configuration information or beam training.

[0011] or,

[0012] When a handover request is received from a terminal, the terminal type is identified based on whether the handover request carries a low-altitude terminal identifier; wherein, the low-altitude terminal identifier is added by the source cell after determining that the terminal is a low-altitude terminal based on the terminal's slice configuration information or beam training.

[0013] As an improvement to the above scheme, the low-altitude terminal includes fixed-contract low-altitude terminals and temporary low-altitude terminals; then, determining the terminal type based on the terminal's slice configuration information or beam training includes:

[0014] The terminal's slice configuration information is obtained. When the slice configuration information meets the preset configuration requirements, the terminal is determined to be a fixed-contract low-altitude terminal.

[0015] A beam management mechanism is used to train the terminal beams; wherein, the beam training includes downlink beam training and uplink beam training; after the downlink beam training is completed, the terminal continuously communicates with the configured non-ground coverage beams for a preset time period, and during the uplink beam training process, the terminal continuously uses the preset downtilt beams for a preset time period, and the terminal is determined to be a temporary low-altitude terminal.

[0016] Otherwise, the terminal is determined to be a non-low-altitude terminal.

[0017] As an improvement to the above solution, the following steps are taken to add a low-altitude terminal identifier to the low-altitude terminal:

[0018] For fixed-contract low-altitude terminals, obtain the low-altitude terminal identifier from the core network and add the low-altitude terminal identifier to the fixed-contract low-altitude terminal; wherein, the low-altitude terminal identifier is generated by the core network after it detects the fixed-contract low-altitude terminal from the slice information during the service request phase;

[0019] For temporary low-altitude terminals, a low-altitude terminal identifier is generated during beam training, and the low-altitude terminal identifier is added to the temporary low-altitude terminal.

[0020] As an improvement to the above solution, configuring a low-altitude mobility strategy for the low-altitude terminal includes:

[0021] When the low-altitude terminal is the first low-altitude terminal, the previously issued ground mobility policy will be updated to a low-altitude mobility policy for the low-altitude terminal; wherein, the first low-altitude terminal is a low-altitude terminal identified by the cell through beam training and marked with a low-altitude terminal identifier.

[0022] When the low-altitude terminal is the second low-altitude terminal, a low-altitude mobility policy for the low-altitude terminal is directly issued after receiving the handover request or during the service establishment process; wherein, the second low-altitude terminal is a low-altitude terminal identified and marked with a low-altitude terminal identifier by other cells.

[0023] As an improvement to the above scheme, the low-altitude mobility strategy includes a handover bias; the handover bias is used as a trigger condition for generating a measurement report of same-frequency handover.

[0024] As an improvement to the above scheme, the low-altitude mobility strategy includes a reporting time interval offset; the reporting time interval offset is used to adjust the reporting time interval of the measurement report.

[0025] As an improvement to the above scheme, the low-altitude mobility strategy includes distance information between the source cell and all handoverable target cells; the distance information is used to set different handover difficulty levels for different target cells.

[0026] As an improvement to the above scheme, the low-altitude mobility strategy includes the distinguishing configuration of neighboring cells for low-altitude terminals and ground terminals, wherein the ground terminals use a linear mobility strategy to configure neighboring cells, and the low-altitude terminals use a planar mobility strategy to configure neighboring cells.

[0027] This invention also provides a mobility strategy adjustment device for a low-altitude terminal, comprising:

[0028] A terminal type identification module is used to identify the terminal type of the terminal; wherein the terminal type is a low-altitude terminal or a non-low-altitude terminal;

[0029] A low-altitude mobility policy allocation module is used to configure a low-altitude mobility policy for the low-altitude terminal when the terminal is a low-altitude terminal.

[0030] The ground mobility policy allocation module is used to configure a ground mobility policy for the non-low-altitude terminal when the terminal is a non-low-altitude terminal.

[0031] This invention also provides a mobility strategy adjustment device for a low-altitude terminal, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the mobility strategy adjustment method for a low-altitude terminal as described in any of the above embodiments.

[0032] This invention also provides a computer-readable storage medium, which includes a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to perform the low-altitude terminal mobility strategy adjustment method as described in any of the preceding embodiments.

[0033] This invention also provides a computer program product, which includes a computer program or computer instructions. When the computer program or computer instructions are executed by a processor, they implement the low-altitude terminal mobility strategy adjustment method as described in any of the above embodiments.

[0034] Compared with existing technologies, the mobility strategy adjustment method, apparatus, device, medium, and product for low-altitude terminals disclosed in this invention are designed to configure different mobility strategies for non-low-altitude terminals and low-altitude terminals. Non-low-altitude terminals use the original ground mobility strategy, while low-altitude terminals use a new low-altitude mobility strategy. Compared to existing technologies where low-altitude terminals uniformly use ground mobility strategies, this invention provides a mobility strategy suitable for low-altitude terminals. It employs additional offsets, adjusts handover request difficulty based on distance, and redefines the neighbor cell relationships of low-altitude terminals to complete the handover process. This solves the problem of uneven energy distribution and signal nulls caused by large antennas facing the ground, leading to coverage holes. Furthermore, it reduces frequent handovers during flight in coverage holes, resulting in unstable handover sequences, differences in test results across the same line, and significant interference from numerous cell signals received by low-altitude terminals in the air. This effectively ensures the communication quality of low-altitude terminals. Attached Figure Description

[0035] Figure 1 This is a flowchart illustrating a method for adjusting the mobility strategy of a low-altitude terminal according to an embodiment of the present invention.

[0036] Figure 2 This is a schematic diagram illustrating the principle of cell distance information in an embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram illustrating the principle of initiating a handover request in an embodiment of the present invention;

[0038] Figure 4 This is a flowchart illustrating a preferred embodiment of the low-altitude terminal mobility strategy adjustment method of the present invention.

[0039] Figure 5 This is a schematic diagram of the structure of a low-altitude terminal mobility strategy adjustment device provided in an embodiment of the present invention. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0042] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0043] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0044] See Figure 1 This is a flowchart illustrating a method for adjusting the mobility strategy of a low-altitude terminal according to an embodiment of the present invention. The method, applied to the base station side, includes steps S11 to S13:

[0045] S11. Identify the terminal type of the terminal; wherein the terminal type is a low-altitude terminal or a non-low-altitude terminal;

[0046] S12. When the terminal is a low-altitude terminal, configure a low-altitude mobility strategy for the low-altitude terminal.

[0047] S13. When the terminal is a non-low-altitude terminal, configure a ground mobility strategy for the non-low-altitude terminal.

[0048] In this embodiment of the invention, in order to solve the problem that in the prior art, low-altitude terminals of 5G wireless networks still rely on the original ground mobility strategy during flight and there is no special adjustment and optimization of the mobility strategy for low-altitude terminals, a new mobility strategy for low-altitude terminals, which is different from the original ground mobility strategy, is set up, namely, the low-altitude mobility strategy.

[0049] During application, the terminal type is identified as either a low-altitude terminal or a non-low-altitude terminal. When the terminal is determined to be a low-altitude terminal, a low-altitude mobility policy is configured for the low-altitude terminal; when the terminal is determined to be a non-low-altitude terminal, a ground mobility policy is configured for the non-low-altitude terminal.

[0050] Preferably, the low-altitude mobility strategy employs additional offset, adjusts the handover request difficulty based on distance, and redefines the neighbor cell relationship of low-altitude terminals to complete the handover process.

[0051] By employing the technical means of this invention, different mobility strategies are specifically configured for non-low-altitude terminals and low-altitude terminals. The original ground mobility strategy is used for non-low-altitude terminals, while a new low-altitude mobility strategy is used for low-altitude terminals. Compared with the prior art where low-altitude terminals also uniformly adopt the ground mobility strategy, this invention provides a mobility strategy suitable for low-altitude terminals. It solves the problem that when a large antenna faces the ground for coverage, low-altitude terminals can only utilize its upper sidelobes, resulting in uneven energy, signal nulls, and coverage holes. Furthermore, it reduces the problems of frequent handovers during flight by terminals in coverage holes, leading to unstable handover sequences, differences in test results between different tests on the same line, and the large number of cell signals received by low-altitude terminals in the air, causing significant interference. This effectively ensures the communication quality of low-altitude terminals.

[0052] As a preferred embodiment, the present invention further implements the above embodiment. Step S11, namely, identifying the terminal type of the terminal, specifically involves:

[0053] The terminal type is determined based on the terminal's slice configuration information or beam training.

[0054] or,

[0055] When a handover request is received from a terminal, the terminal type is identified based on whether the handover request carries a low-altitude terminal identifier; wherein, the low-altitude terminal identifier is added by the source cell after determining that the terminal is a low-altitude terminal based on the terminal's slice configuration information or beam training.

[0056] In this embodiment of the invention, the terminal moves between different cells. When the terminal starts up in the source cell, the source cell determines whether the terminal is a low-altitude terminal based on the terminal's slice configuration information or beam training, and configures a corresponding mobility policy. When the terminal prepares to hand over from the source cell to the target cell, it sends a handover request to the target cell. For handovers of low-altitude terminals, the source cell adds a low-altitude terminal identifier to the handover request. When the target cell receives the handover request, it can determine whether the terminal is a low-altitude terminal based on whether the handover request carries the low-altitude terminal identifier, and configures a corresponding mobility policy after the terminal hands over. This includes measurement frequency, hysteresis, offset, neighbor cell configuration, and handover trigger difficulty level. Subsequently, the cell continues to periodically determine whether the terminal maintains a low-altitude state through beam scanning and training. For terminals that are no longer low-altitude, the policy is changed to a ground mobility policy and the measurement configuration is reissued.

[0057] As a preferred embodiment, the present invention further explains the means for determining the terminal type. The low-altitude terminal includes fixed-contract low-altitude terminals and temporary low-altitude terminals; therefore, determining the terminal type based on the terminal's slice configuration information or beam training includes the following steps:

[0058] The terminal's slice configuration information is obtained. When the slice configuration information meets the preset configuration requirements, the terminal is determined to be a fixed-contract low-altitude terminal.

[0059] A beam management mechanism is used to train the terminal beams; wherein, the beam training includes downlink beam training and uplink beam training; after the downlink beam training is completed, the terminal continuously communicates with the configured non-ground coverage beams for a preset time period, and during the uplink beam training process, the terminal continuously uses the preset downtilt beams for a preset time period, and the terminal is determined to be a temporary low-altitude terminal.

[0060] Otherwise, the terminal is determined to be a non-low-altitude terminal.

[0061] In this embodiment of the invention, the entire scheme mainly includes three stages: low-altitude terminal identification, low-altitude terminal identifier transmission, and low-altitude terminal mobility policy modification. In this embodiment of the invention, the low-altitude terminals are divided into fixed-contract low-altitude terminals and temporary low-altitude terminals. Fixed-contract low-altitude terminals are judged using slice offset information, while temporary low-altitude terminals are judged using beam training. If neither of these two conditions is met, the terminal is considered a non-low-altitude terminal.

[0062] Fixed-signature low-altitude terminals are IoT low-altitude contract users. Their SIM cards are bound to a special 5G slice specifically for low-altitude flight services. The cell side determines a terminal as a fixed-signature low-altitude terminal based on slice information. Simultaneously, the cell also determines a terminal as a temporary low-altitude terminal through uplink and downlink beam scanning and the training process. Therefore, the cell side assigns a low-altitude terminal identifier to both fixed-signature and temporary low-altitude terminals.

[0063] Specifically, during the transition from idle to connected state in a cell, the user terminal sends a service request message to the AMF (Access and Mobility Management Function) to request the establishment of an N1 NAS (Non-Access Stratum) signaling connection, and / or to request the establishment of user plane resources for a PDU (Protocol Data Unit) session that lacks user plane resources. IoT low-altitude users initiate service requests to the 5G cell through a special slice configuration (SST+SD). The cell side, through the slice configuration information, identifies the user initiating the service request as an IoT low-altitude terminal and assigns it a fixed-subscription low-altitude terminal identifier.

[0064] Since low-altitude economy is a near-term development direction and there is currently no specific method for determining the low-altitude status of terminals in the network, a unified mobility policy configuration method for all terminals is adopted. This embodiment of the invention targets terminals temporarily in a low-altitude state, utilizing uplink and downlink beam scanning, beam measurement, beam reporting, and beam indication processes in the NR network to jointly determine whether the terminal UE is in a low-altitude environment.

[0065] Preferably, the following steps are used to make the determination:

[0066] A beam management mechanism is used to train the terminal's beams; wherein, the beam training includes downlink beam training and uplink beam training;

[0067] After completing downlink beam training, configure the terminal with a non-terrestrial coverage beam;

[0068] When the terminal continuously communicates using the non-ground coverage beam within a preset time period, the terminal is determined to be a low-altitude terminal.

[0069] During uplink beam training, if the terminal continuously uses a preset downtilt beam within a preset time period, the terminal is determined to be a temporary low-altitude terminal.

[0070] Specifically, the beam management mechanism in NR mainly includes the following processes:

[0071] Beam scanning: The beam that transmits the reference signal performs spatial scanning at predefined time intervals;

[0072] Beam measurement / decision: The UE measures the reference signal and selects the best beam.

[0073] Beam Reporting: For UEs, report beam measurement results;

[0074] Beam indication: The base station instructs the UE to select a specified beam;

[0075] Beam failure recovery: This includes beam failure detection, discovery of new beams, and beam recovery process.

[0076] The reference signals used for downlink beam management include:

[0077] Idle state initial access: SSB (Synchronization Signal Block);

[0078] Connected state: CSI-RS (Channel Status Information-Reference Signal) or SSB;

[0079] Reference signal used for uplink beam management:

[0080] Idle-state initial access: PRACH (Physical Random Access Channel);

[0081] Connected state: SRS (Sounding Reference Signal).

[0082] Furthermore, determining temporary low-altitude terminals based on downlink beams and determining user locations based on downlink beams includes two processes: initial coarse beam determination and subsequent narrow beam determination.

[0083] The first process involves initial coarse beam determination based on SSB: In the current network NR (2.6G or 4.9G) downlink SSB signal, each half-frame (5ms) contains 8 SSB blocks. Generally, these are sent in a time-polling manner according to a certain beam direction. Before initiating initial access in the idle state, the UE performs SSB reception (UE implementation). When the SSB measurement result meets the RSRP (Reference Signal Received Power) threshold, the SSB beam (strongest) is selected to transmit the PRACH process (based on the PRACH index carried by the SSB). Otherwise, any SSB beam can be selected. The transmission time of the PRACH and the SSB index (beam) have a mapping relationship. The UE selects the associated PRACH transmission time (uplink beam) to transmit MSG1. The base station determines the beam of the SSB where the UE is located based on the resource location of the UE's uplink PRACH and transmits the downlink RAR (Random Access Response) (MSG2) on this beam. During the initial access process, the UE and the base station complete the preliminary training process based on the SSB beam (coarse beam training). The base station can use this process to determine which coarse beam coverage area the UE is in.

[0084] The second process, narrow beam determination based on SSB (downlink beam training): SSB beams achieve coverage for initial cell access. In order to obtain better wireless performance, the base station can select a better beam for transmission through the beam training process.

[0085] After the terminal enters the RRC (Radio Resource Control) connected state, downlink beam training can be performed using the CSI-RS signal. The specific training strategy protocol is not specified and is implemented independently by each manufacturer. The general principle is as follows: The base station transmits multiple narrow beams (CSI-RS corresponding to CSI Resource Index, CRI) around the initial access SSB beam for beam scanning. The UE maintains its received beam unchanged. The UE measures the CSI-RS reference signal to obtain the L1-RSRP result and reports the measurement results of different CRIs to the base station. The base station selects the beam corresponding to the CSI-RS with the strongest L1-RSRP for downlink channel indication (TCI). The TCI State information for PDSCH in the protocol is first configured in the RRC signaling (UE level), with a maximum of 128 states (8 narrow beams corresponding to a single SSB signal). For the UE, the TCI State list configured in the RRC signaling is a pool of various downlink beams (PDSCH / PDCCH / CSI-RS), and the base station still needs to further indicate the specific beam information.

[0086] The current CSI-RS beam direction static weight definition is configured with 32 narrow beams, divided into 4 height layers. This can be understood as each SSB beam corresponding to 4 CSI-RS beams (4 layers, divided according to terminal height). The current CSI-RS beam consists of 32 beams, divided into 4 layers vertically and 8 narrow beams per layer horizontally.

[0087] Downlink beam training is divided into two processes: downlink CSI-RS beam transmission training and downlink CSI-RS beam reception training. On the cell side, based on the preamble fed back during the PRACH process, the terminal location is estimated. According to the static relationship between CSI-RS and SSB signals, UE-level CSI-RS is configured at the RRC level in this SSB beam direction. The terminal receives the feedback CRI (CSI-RS id) and the corresponding RSRP. The cell selects the beam weights based on the strongest RSRP (completing the downlink beam transmission training process), repeatedly transmitting CSI-RS to the terminal with a narrow beam. After collecting signals with multiple beam widths, the terminal decides which narrow beam to receive the signal (completing the downlink beam reception training process).

[0088] The beam relationship is transmitted through QCL, that is, CSI-RS BM (beam management) is "close" to the previous downlink reference signal SSB beam, but not exactly the same. Therefore, training from wide beam to narrow beam can be performed in the downlink direction.

[0089] On the cell side, for CSI-RS users with the strongest CSI-RSRP configuration from the UE side that are not covered by ground (CSI narrow beams configured in elevation mode compared to SSB signals), and maintain them for a certain period of time (the time threshold can be set and defined on the GNB side, such as 5 seconds, meaning that all PDCCH narrow beams (Resource1) scheduled to cover the user within 5 seconds are non-ground coverage beams) are tagged, judged as suspected low-altitude terminals, and then proceed to the next uplink beam training and reconfirmation process.

[0090] Narrow beam determination based on SRS (uplink beam training):

[0091] In the uplink direction, beam training is performed via SRS. The number of SRS resource sets used for beam management, and the number of SRS resources in each resource set, are related to the UE's capabilities and are defined in 3GPP 38.306. Multiple SRS resource sets used for beam management correspond to the UE's TXPanel. Each SRS resource set within an SRS resource set corresponds to one beam; therefore, multiple SRS resources within a single resource set cannot be transmitted simultaneously—only one beam can be transmitted at a time. SRS resources from different resource sets can be transmitted simultaneously (depending on the UE's capabilities). The UE can only select one set of resources for transmission at a time. SRS beam training can be implemented by the UE performing beam scanning itself or by the gNB performing receive scanning.

[0092] SRS Beam Management: The SRS configuration includes dedicated resources for beam management. If this resource is not configured, the uplink beam is determined using uplink and downlink reciprocity. When SRS resources for beam management are configured, higher-layer signaling configures one or more SRS-ResourceSets (maximum 16) via SRS-Config; each SRS-ResourceSet configures one or more SRS-Resources (K maximum 64). One SRSResource in an SRS resource set corresponds to one beam. Therefore, multiple SRS Resources from the same resource set cannot be transmitted simultaneously; only one beam can be transmitted at a time. SRS Resources from different resource sets can be transmitted simultaneously.

[0093] For uplink beam training, the spatialRelationlnfo (spatial relationship information) indicated by the base station specifies the corresponding uplink beam. The reference signal beam is exactly the same, and progressive beam refinement training is not supported. When the spatialRelationlnfo of one or more SRS resources in an SRS resource set is configured with different transmit beams, the UE performs transmit beam scanning, and the base station can keep the receive beam unchanged to perform uplink beam training.

[0094] For terminals identified as suspected low-altitude users during downlink beam training, their uplink beam training results are checked. If the UE-side PUSCH beam training ultimately adopts a downtilted beam (in DCI 0_1 of the PDCCH, the corresponding SRS resource is indicated by the SRSresourceindicator field, which "implicitly" represents the PUSCH uplink beam), and maintains it for a certain period of time (this time threshold can be defined on the GNB side, such as 5 seconds, meaning that within 5 seconds, the beam Resource4 based on SRS BM is a narrow beam pointing downwards from the user), then the low-altitude terminal is determined to be a temporary low-altitude terminal, and the user is marked with a temporary low-altitude terminal identifier.

[0095] As a preferred embodiment, the present invention further implements the above embodiments by adding a low-altitude terminal identifier to the low-altitude terminal through the following steps:

[0096] For fixed-contract low-altitude terminals, obtain the low-altitude terminal identifier from the core network and add the low-altitude terminal identifier to the fixed-contract low-altitude terminal; wherein, the low-altitude terminal identifier is generated by the core network after it detects the fixed-contract low-altitude terminal from the slice information during the service request phase;

[0097] For temporary low-altitude terminals, a low-altitude terminal identifier is generated during beam training, and the low-altitude terminal identifier is added to the temporary low-altitude terminal.

[0098] In this embodiment of the invention, the identification of fixed-contract low-altitude terminals and temporary low-altitude terminals are transmitted in different ways. The identification of fixed-contract low-altitude terminals is sent from the core network side to the radio network base station GNB side. Specifically, the core network senses low-altitude users from slice information and sends it to the GNB side during the service request phase. The identification of temporary low-altitude terminals is determined autonomously by the radio network GNB side based on beam training.

[0099] This is a policy index that the operator registers in the UDM (Unified Data Management) database for fixed-contract low-altitude terminals. During the initial registration process for a user joining the network, the AMF (Agency Management Function) transmits the fixed-altitude terminal policy (index) to the GNB (Network Buffer) side through the NG (Network Container Registry). After the GNB side maps and configures the index locally, it can provide special RRM (Remote Response Management) policies for fixed-altitude low-altitude terminals based on the index, thereby providing targeted mobility policies.

[0100] UE initial access process: UDM transmits the operator's low-altitude policy configuration to AMF through N8 interface messages, and AMF transmits the low-altitude index transmitted by UDM to the GNB side through INITIAL CONTEXT SETUP REQUEST message.

[0101] NG link established: If a fixed low-altitude contracted terminal enters the connected state from the idle state, the AMF will pass the low-altitude policy index transmitted by the UDM to the gNodeB via the DOWNLINKNAS TRANSPORT message.

[0102] When a UE performs an NG handover: the source GNB transmits the low-altitude policy index to the AMF via a HANDOVER REQUIRED message, and then the AMF transmits the low-altitude policy index to the target gNodeB via a HANDOVER REQUEST message.

[0103] When a UE performs an Xn handover: the source GNB transmits the low-altitude policy index obtained from the AMF to the target gNodeB via a HANDOVER REQUEST message.

[0104] Using the technical means of this invention, fixed contracted users are judged using slice configuration information, temporary users are judged using a combination of user beam scanning and training process, and the low-altitude terminal attribute transmission is completed by adding a low-altitude terminal identifier during the handover process. The low-altitude terminal mobility strategy is to use different handover judgment strategies for users judged as low-altitude terminals to complete the handover process, so as to ensure the communication quality of low-altitude terminals without affecting the existing ground network.

[0105] As a preferred embodiment, the present invention further implements the above embodiments. In step S12, configuring a low-altitude mobility strategy for the low-altitude terminal includes:

[0106] When the low-altitude terminal is the first low-altitude terminal, the previously issued ground mobility policy will be updated to a low-altitude mobility policy for the low-altitude terminal; wherein, the first low-altitude terminal is a low-altitude terminal identified by the cell through beam training and marked with a low-altitude terminal identifier.

[0107] When the low-altitude terminal is the second low-altitude terminal, a low-altitude mobility policy for the low-altitude terminal is directly issued after receiving the handover request or during the service establishment process; wherein, the second low-altitude terminal is a low-altitude terminal identified and marked with a low-altitude terminal identifier by other cells.

[0108] In this embodiment of the invention, user terminals carrying low-altitude terminal identifiers are distinguished into those identified as low-altitude terminals in the cell (first low-altitude terminal), that is, the cell determines that the terminal is a low-altitude terminal through beam training, and those whose low-altitude terminal identifiers are transmitted by other cells (second low-altitude terminal), including fixed contracted low-altitude terminals or temporary low-altitude terminals switched in.

[0109] For any low-altitude terminal identified in this cell, the previously issued measurement configuration for ground users will be removed and replaced with a new low-altitude mobility policy for low-altitude terminals. For low-altitude terminals that transmit low-altitude terminal identifiers, the new low-altitude mobility policy for low-altitude terminals will be issued directly during handover or service establishment.

[0110] In a preferred embodiment, the low-altitude mobility strategy includes a handover bias; the handover bias is used as a trigger condition for generating a measurement report of same-frequency handover.

[0111] The low-altitude mobility strategy includes a reporting time interval offset; the reporting time interval offset is used to adjust the reporting time interval of measurement reports.

[0112] The low-altitude mobility strategy includes distance information between the source cell and all handoverable target cells; the distance information is used to set different handover difficulty levels for different target cells.

[0113] The low-altitude mobility strategy includes the configuration of neighboring cells for low-altitude terminals and ground terminals. The ground terminals use a linear mobility strategy to configure neighboring cells, while the low-altitude terminals use a planar mobility strategy to configure neighboring cells.

[0114] In this embodiment of the invention, the following improvements are made to the low-altitude mobility strategy for low-altitude terminals: adding a handover bias term, adding a measurement report reporting time interval bias, adding source cell and target cell distance judgment on the GNB side, and configuring neighbor cell distinction between low-altitude terminals and ground terminals.

[0115] Specifically, increase the switching bias:

[0116] For low-altitude terminals, the measurement configuration mainly includes two parts: the measurement object and the report configuration. The new field is used to add handover offset. Taking the existing A3 measurement report used for same-frequency handover as an example:

[0117] It's important to note that the A3 event is a measurement reporting event defined in 5G (NR) networks. Specifically, the A3 event occurs when the signal quality of a neighboring cell is significantly better than the signal quality of the currently serving cell, triggering a measurement and report by the terminal (UE). This event is typically used to determine whether the UE should switch to a neighboring cell to optimize network connectivity and user experience.

[0118] In 5G networks, the triggering conditions for an A3 event typically involve multiple parameters, including the signal quality of the serving cell and neighboring cells (such as RSRP), offset, hysteresis parameter, and trigger time (TimeToTrig). When the signal quality of a neighboring cell exceeds that of the serving cell by a certain amount (i.e., offset plus the serving cell's signal quality) and this exceeds the threshold for a certain period (i.e., the trigger time), the A3 event is triggered. The UE then reports this event to the network, prompting the network to perform a cell handover operation.

[0119] The existing A3 event entry condition is: Mn+Ofn+Ocn-Hys>Ms+Ofs+Ocs+Off, and the A3 measurement report is reported after the above condition is maintained for TimeToTrig time.

[0120] In this embodiment of the invention, a switching bias Off2 is added to the original Off. For terminals determined to be at low altitude, the entry condition for event A3 is changed as follows:

[0121] Mn+Ofn+Ocn-Hys>Ms+Ofs+Ocs+Off+Off2;

[0122] Off2 is a new handover offset specifically applied to low-altitude terminals. It is set by the GNB side and is only sent to users identified as low-altitude terminals. The offset is only activated after the terminal receives the special offset; otherwise, it is defined as 0.

[0123] Furthermore, increase the reporting time interval offset:

[0124] In existing measurement reports, the TimeToTrig time interval was used as the judgment duration. If the conditions were met within this time, the report was submitted for the first time. This embodiment of the invention adds a TimeToTrigoffset field under reportconfig. This field has two sets of information elements: TimeToTrigoffset1 exists as a multiple, indicating that the actual control duration has changed to TimeToTrig * TimeToTrigoffset1; TimeToTrigoffset2 exists as an offset, indicating that the actual control duration has changed to TimeToTrig + TimeToTrigoffset2. When both exist, TimeToTrigoffset1 is selected.

[0125] Further, the distance information to the target cell:

[0126] The source cell initially stores distance information for all target cells for handover. Based on a relative distance threshold, target cells are categorized into short-range, long-range, and ultra-long-range handover target cells. Different handover difficulty levels are assigned to different target cells.

[0127] See Figure 2 and Figure 3 , Figure 2 This is a schematic diagram illustrating the principle of cell distance information in an embodiment of the present invention. Figure 3 This is a schematic diagram illustrating the principle of initiating a handover request in an embodiment of the present invention. After the low-altitude terminal reports a measurement report, the source cell performs target cell analysis based on the measurement report for the handover purpose, and triggers different handover attempts for cells at different distances.

[0128] If the target cell is nearby, the handover request is forwarded to the target cell side, and a handover request is initiated once the MR is triggered.

[0129] If the target cell is far away, ignore the initial measurement report sent to that cell for handover, wait for the terminal to switch from event reports to periodic reports, and after receiving the Nth periodic report, initiate a handover request to the target cell.

[0130] If the target cell is an ultra-long-distance cell, the initial measurement report for handover to that cell is ignored. The terminal waits for the event report to switch to a periodic report. After receiving the Mth periodic report, a handover request is initiated to the target cell.

[0131] Furthermore, the neighboring cell configurations for low-altitude terminals and ground terminals are further differentiated:

[0132] The cell side configures two different neighbor cell strategies for ground terminals and low-altitude terminals. Ground terminals are configured with neighbor cells using a linear user movement strategy, while low-altitude terminals are configured with neighbor cells using a planar movement strategy.

[0133] When a low-altitude terminal is flying at low altitude, after the radio side determines that it is a low-altitude terminal, based on the measurement report used for handover purposes, the source cell side decides whether to initiate a handover request according to whether the target cell is configured as a low-altitude neighbor cell.

[0134] See Figure 4This is a flowchart illustrating a preferred method for adjusting the mobility policy of a low-altitude terminal according to an embodiment of the present invention. For terminals (fixed or temporary) identified as low-altitude users, a low-altitude terminal identifier is added to the Handover Request message (Xn handover) or Handover Required message (N2 handover) during handover, for inter-cell transmission of low-altitude terminal attributes. Taking the Handover Request message (Xn handover) as an example, a Low altitude state information element is added to the UE HistoryInformation information element in the Handover Request signaling. 0 indicates that the current cell has not identified it as a low-altitude terminal, and 1 indicates that the current cell has identified it as a low-altitude terminal. The handover process carries the current cell's assessment of the terminal's low-altitude characteristics, allowing the target cell to promptly issue a low-altitude terminal mobility policy after the terminal hands over. For the handover-in low-altitude terminal, the target cell directly issues a mobility policy specifically for the low-altitude terminal.

[0135] Using the technical means of this invention, the cell side assigns a low-altitude terminal identifier to terminals identified as low-altitude terminals. During the handover request process, this identifier is added to the signaling. After a low-altitude user hands over to the target cell, different mobility measurement frequencies, hysteresis, offsets, neighbor cell configurations, and handover trigger difficulty levels are allocated. For low-altitude terminals, special handover offsets and reporting time offsets are added to adjust the handover difficulty. The cell side increases the number of reporting attempts to trigger the handover request difficulty based on the distance level of the target cell. Different neighbor cell relationship groups are configured for ground terminals and low-altitude terminals, thereby configuring appropriate low-altitude mobility strategies for low-altitude terminals and ensuring their communication quality.

[0136] See Figure 5 This is a schematic diagram of the structure of a low-altitude terminal mobility strategy adjustment device provided in an embodiment of the present invention. The embodiment of the present invention provides a low-altitude terminal mobility strategy adjustment device 10, comprising:

[0137] Terminal type identification module 11 is used to identify the terminal type of the terminal; wherein the terminal type is a low-altitude terminal or a non-low-altitude terminal;

[0138] The low-altitude mobility strategy allocation module 12 is used to configure a low-altitude mobility strategy for the low-altitude terminal when the terminal is a low-altitude terminal.

[0139] The ground mobility policy allocation module 13 is used to configure a ground mobility policy for the non-low-altitude terminal when the terminal is a non-low-altitude terminal.

[0140] In a preferred embodiment, the terminal type identification module is specifically used for:

[0141] The terminal type is determined based on the terminal's slice configuration information or beam training.

[0142] or,

[0143] When a handover request is received from a terminal, the terminal type is identified based on whether the handover request carries a low-altitude terminal identifier; wherein, the low-altitude terminal identifier is added by the source cell after determining that the terminal is a low-altitude terminal based on the terminal's slice configuration information or beam training.

[0144] In a preferred embodiment, the low-altitude terminal includes fixed-contract low-altitude terminals and temporary low-altitude terminals; then, determining the terminal type based on the terminal's slice configuration information or beam training includes:

[0145] The terminal's slice configuration information is obtained. When the slice configuration information meets the preset configuration requirements, the terminal is determined to be a fixed-contract low-altitude terminal.

[0146] A beam management mechanism is used to train the terminal beams; wherein, the beam training includes downlink beam training and uplink beam training; after the downlink beam training is completed, the terminal continuously communicates with the configured non-ground coverage beams for a preset time period, and during the uplink beam training process, the terminal continuously uses the preset downtilt beams for a preset time period, and the terminal is determined to be a temporary low-altitude terminal.

[0147] Otherwise, the terminal is determined to be a non-low-altitude terminal.

[0148] As a preferred implementation, a low-altitude terminal identifier is added to the low-altitude terminal through the following steps:

[0149] For fixed-contract low-altitude terminals, obtain the low-altitude terminal identifier from the core network and add the low-altitude terminal identifier to the fixed-contract low-altitude terminal; wherein, the low-altitude terminal identifier is generated by the core network after it detects the fixed-contract low-altitude terminal from the slice information during the service request phase;

[0150] For temporary low-altitude terminals, a low-altitude terminal identifier is generated during beam training, and the low-altitude terminal identifier is added to the temporary low-altitude terminal.

[0151] In a preferred embodiment, the low-altitude mobility strategy allocation module 12 is specifically used for:

[0152] When the low-altitude terminal is the first low-altitude terminal, the previously issued ground mobility policy will be updated to a low-altitude mobility policy for the low-altitude terminal; wherein, the first low-altitude terminal is a low-altitude terminal identified by the cell through beam training and marked with a low-altitude terminal identifier.

[0153] When the low-altitude terminal is the second low-altitude terminal, a low-altitude mobility policy for the low-altitude terminal is directly issued after receiving the handover request or during the service establishment process; wherein, the second low-altitude terminal is a low-altitude terminal identified and marked with a low-altitude terminal identifier by other cells.

[0154] In a preferred embodiment, the low-altitude mobility strategy includes a handover bias; the handover bias is used as a trigger condition for generating a measurement report of same-frequency handover.

[0155] The low-altitude mobility strategy includes a reporting time interval offset; the reporting time interval offset is used to adjust the reporting time interval of measurement reports.

[0156] The low-altitude mobility strategy includes distance information between the source cell and all handoverable target cells; the distance information is used to set different handover difficulty levels for different target cells.

[0157] The low-altitude mobility strategy includes the configuration of neighboring cells for low-altitude terminals and ground terminals. The ground terminals use a linear mobility strategy to configure neighboring cells, while the low-altitude terminals use a planar mobility strategy to configure neighboring cells.

[0158] By employing the technical means of this invention, different mobility strategies are specifically configured for non-low-altitude terminals and low-altitude terminals. The original ground mobility strategy is used for non-low-altitude terminals, while a new low-altitude mobility strategy is used for low-altitude terminals. Compared to the prior art where low-altitude terminals also uniformly adopt a ground mobility strategy, this invention provides a mobility strategy suitable for low-altitude terminals. It completes the handover process by adding an offset, adjusting the handover request difficulty based on distance, and redefining the neighbor cell relationship of low-altitude terminals. This solves the problem of uneven energy distribution and signal nulls caused by large antennas facing the ground, resulting in coverage holes. Furthermore, it reduces frequent handovers during flight in coverage holes, leading to unstable handover sequences, differences in test results across the same line, and significant interference from numerous cell signals received by low-altitude terminals in the air. This effectively ensures the communication quality of low-altitude terminals.

[0159] It should be noted that the low-altitude terminal mobility strategy adjustment device provided in this embodiment of the invention is used to execute all the process steps of the low-altitude terminal mobility strategy adjustment method in the above embodiment. The working principle and beneficial effects of the two are one-to-one, so they will not be described again.

[0160] This invention also provides a mobility strategy adjustment device for a low-altitude terminal, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the mobility strategy adjustment method for a low-altitude terminal as described in any of the above embodiments.

[0161] This invention also provides a computer-readable storage medium, which includes a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to perform the low-altitude terminal mobility strategy adjustment method as described in any of the above embodiments.

[0162] This invention also provides a computer program product, which includes a computer program or computer instructions. When the computer program or computer instructions are executed by a processor, they implement the low-altitude terminal mobility strategy adjustment method as described in any of the above embodiments.

[0163] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0164] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for adjusting the mobility strategy of a low-altitude terminal, characterized in that, include: Identify the terminal type; wherein the terminal type is a low-altitude terminal or a non-low-altitude terminal; When the terminal is a low-altitude terminal, a low-altitude mobility strategy is configured for the low-altitude terminal. When the terminal is a non-low-altitude terminal, a ground mobility strategy is configured for the non-low-altitude terminal. Configuring a low-altitude mobility strategy for the low-altitude terminal includes: When the low-altitude terminal is the first low-altitude terminal, the previously issued ground mobility policy will be updated to a low-altitude mobility policy for the low-altitude terminal; wherein, the first low-altitude terminal is a low-altitude terminal identified by the cell through beam training and marked with a low-altitude terminal identifier. When the low-altitude terminal is the second low-altitude terminal, a low-altitude mobility policy for the low-altitude terminal is directly issued after receiving the terminal's handover request or during the service establishment process; wherein, the second low-altitude terminal is a low-altitude terminal identified and marked with a low-altitude terminal identifier by other cells.

2. The method for adjusting the mobility strategy of a low-altitude terminal as described in claim 1, characterized in that, The terminal type of the identification terminal is specifically: The terminal type is determined based on the terminal's slice configuration information and beam training. or, When a handover request is received from a terminal, the terminal type is identified based on whether the handover request carries a low-altitude terminal identifier; wherein, the low-altitude terminal identifier is added by the source cell after determining that the terminal is a low-altitude terminal based on the terminal's slice configuration information or beam training.

3. The method for adjusting the mobility strategy of a low-altitude terminal as described in claim 2, characterized in that, The low-altitude terminals include fixed contracted low-altitude terminals and temporary low-altitude terminals. The step of determining the terminal type based on the terminal's slice configuration information or beam training includes: The terminal's slice configuration information is obtained. When the slice configuration information meets the preset configuration requirements, the terminal is determined to be a fixed-contract low-altitude terminal. A beam management mechanism is used to train the terminal beams; wherein, the beam training includes downlink beam training and uplink beam training; after the downlink beam training is completed, the terminal continuously communicates with the configured non-ground coverage beams for a preset time period, and during the uplink beam training process, the terminal continuously uses the preset downtilt beams for a preset time period, and the terminal is determined to be a temporary low-altitude terminal. Otherwise, the terminal is determined to be a non-low-altitude terminal.

4. The method for adjusting the mobility strategy of a low-altitude terminal as described in claim 3, characterized in that, Add a low-altitude terminal identifier to a low-altitude terminal by following these steps: For fixed-contract low-altitude terminals, obtain the low-altitude terminal identifier from the core network and add the low-altitude terminal identifier to the fixed-contract low-altitude terminal; wherein, the low-altitude terminal identifier is generated by the core network after it detects the fixed-contract low-altitude terminal from the slice information during the service request phase; For temporary low-altitude terminals, a low-altitude terminal identifier is generated during beam training, and the low-altitude terminal identifier is added to the temporary low-altitude terminal.

5. The method for adjusting the mobility strategy of a low-altitude terminal as described in claim 1, characterized in that, The low-altitude mobility strategy includes a handover bias; the handover bias is used as a trigger condition for generating a measurement report on same-frequency handover.

6. The method for adjusting the mobility strategy of a low-altitude terminal as described in claim 1, characterized in that, The low-altitude mobility strategy includes a reporting time interval offset; the reporting time interval offset is used to adjust the reporting time interval of measurement reports.

7. The method for adjusting the mobility strategy of a low-altitude terminal as described in claim 1, characterized in that, The low-altitude mobility strategy includes distance information between the source cell and all handoverable target cells; the distance information is used to set different handover difficulty levels for different target cells.

8. The method for adjusting the mobility strategy of a low-altitude terminal as described in claim 1, characterized in that, The low-altitude mobility strategy includes the configuration of neighboring cells for low-altitude terminals and ground terminals. The ground terminals use a linear mobility strategy to configure neighboring cells, while the low-altitude terminals use a planar mobility strategy to configure neighboring cells.

9. A mobility strategy adjustment device for a low-altitude terminal, characterized in that, include: A terminal type identification module is used to identify the terminal type of the terminal; wherein the terminal type is a low-altitude terminal or a non-low-altitude terminal; A low-altitude mobility policy allocation module is used to configure a low-altitude mobility policy for the low-altitude terminal when the terminal is a low-altitude terminal. A ground mobility policy allocation module is used to configure a ground mobility policy for a non-low-altitude terminal when the terminal is a non-low-altitude terminal. The low-altitude mobility strategy allocation module is specifically used for: When the low-altitude terminal is the first low-altitude terminal, the previously issued ground mobility policy will be updated to a low-altitude mobility policy for the low-altitude terminal; wherein, the first low-altitude terminal is a low-altitude terminal identified by the cell through beam training and marked with a low-altitude terminal identifier. When the low-altitude terminal is the second low-altitude terminal, a low-altitude mobility policy for the low-altitude terminal is directly issued after receiving the terminal's handover request or during the service establishment process; wherein, the second low-altitude terminal is a low-altitude terminal identified and marked with a low-altitude terminal identifier by other cells.

10. A mobility strategy adjustment device for a low-altitude terminal, characterized in that, The system includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements the mobility strategy adjustment method for a low-altitude terminal as described in any one of claims 1 to 8.

11. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored computer program, wherein, when the computer program is executed, it controls the device on which the computer-readable storage medium is located to perform the low-altitude terminal mobility strategy adjustment method as described in any one of claims 1 to 8.

12. A computer program product, characterized in that, The computer program product includes a computer program or computer instructions, which, when executed by a processor, implement the mobility strategy adjustment method for a low-altitude terminal as described in any one of claims 1 to 8.

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