Switching method and device, communication equipment and chip

Abstract

Disclosed are a switching method and apparatus, a communication device and a chip, the method comprising: a first base station obtaining first information of a user equipment, the first information comprising at least one of the following: a position, a moving direction, a speed and an acceleration; the first base station determines a candidate base station list according to the first information of the user equipment, and sends a switching request to each candidate base station in the candidate base station list;

Description

Technical Field

[0001] This application relates to the field of mobile communication technologies, and in particular, to a handover method, apparatus, communication device, and chip. Background Art

[0002] In the current 3rd Generation Partnership Project (3GPP) R17 standard, only the enhancement of the triggering conditions for Conditional Handover (CHO) is proposed for in-satellite / inter-satellite handover. In actual network deployment scenarios, mobile terminals face the problem of service continuity between Non-Terrestrial Networks (NTN) and Terrestrial Networks (TN). Currently, in satellite-terrestrial network handover, in the conditional handover scenario, it is still necessary to improve the selection of appropriate candidate base stations to enhance handover efficiency. Summary of the Invention

[0003] To solve the above technical problems, embodiments of this application provide a handover method, apparatus, communication device, and chip.

[0004] Embodiments of this application provide a handover method, which includes:

[0005] A first base station obtains first information of a user equipment, where the first information includes at least one of the following: location, moving direction, speed, and acceleration;

[0006] The first base station determines a candidate base station list according to the first information of the user equipment, and sends a handover request to each candidate base station in the candidate base station list.

[0007] Embodiments of this application provide a handover apparatus, which includes:

[0008] An obtaining unit, configured to obtain first information of a user equipment, where the first information includes at least one of the following: location, moving direction, speed, and acceleration;

[0009] A determining unit, configured to determine a candidate base station list according to the first information of the user equipment;

[0010] A sending unit, configured to send a handover request to each candidate base station in the candidate base station list.

[0011] The communication device provided by embodiments of this application includes: a processor and a memory. The memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute any of the above handover methods.

[0012] The chip provided by the embodiment of the present application includes: a processor, configured to call and run a computer program from a memory, so that a device installed with the chip executes any one of the above methods.

[0013] In the above technical solution of the embodiment of the present application, the first base station obtains first information of a user equipment, where the first information includes at least one of the following: location, moving direction, speed, and acceleration; the first base station determines a candidate base station list according to the first information of the user equipment, and sends a handover request to each candidate base station in the candidate base station list. By introducing the acquisition of the first information of the user equipment based on an improved positioning process, the candidate base station list is determined based on the first information. In this way, a suitable candidate base station list is determined through the first information, the handover efficiency is improved, and at the same time, the problem of resource waste caused by resource reservation of a large number of candidate base stations can also be reduced. In addition, this conditional handover method can greatly reduce the preparation time for inter-network handover from the first base station to the base stations in the candidate base station list in the existing network, and improve the handover accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The drawings described herein are used to provide a further understanding of the present application, and constitute a part of the present application. The illustrative embodiments and descriptions thereof of the present application are used to explain the present application, and do not constitute an improper limitation to the present application.

[0015] FIG. 1(a) is a schematic diagram of a demand scenario for inter-network handover provided by an embodiment of the present application;

[0016] FIG. 1(b) is a schematic diagram of a demand scenario for inter-network handover provided by an embodiment of the present application; Figure 2 ;

[0017] Figure 2 is a schematic flowchart of an existing conditional handover provided by an embodiment of the present application;

[0018] FIG. 3(a) is a schematic flowchart of a round-trip time positioning process provided by an embodiment of the present application;

[0019] FIG. 3(b) is a schematic diagram of a mirror point in a specific NTN scenario provided by an embodiment of the present application;

[0020] FIG. 4(a) is a schematic diagram of an effective neighbor cell range in an NTN to TN scenario provided by an embodiment of the present application;

[0021] FIG. 4(b) is a schematic diagram of an effective neighbor cell range in a TN to NTN scenario provided by an embodiment of the present application;

[0022] Figure 5 is a schematic flowchart of a handover method provided by an embodiment of the present application;

[0023] FIG. 6(a) is a schematic diagram showing how an NTN cell obtains the moving direction of a user equipment according to an embodiment of the present application;

[0024] FIG. 6(b) is a schematic diagram showing how a TN cell obtains the moving direction of a user equipment according to an embodiment of the present application;

[0025] FIG. 7(a) is a schematic flowchart showing how to obtain a handover opportunity from an NTN base station to a TN base station according to an embodiment of the present application;

[0026] FIG. 7(b) is a schematic flowchart showing how to obtain a handover opportunity from a TN base station to an NTN base station according to an embodiment of the present application;

[0027] FIG. 8(a) is a schematic flowchart of an inter-network handover method for satellite-ground collaborative networking according to an embodiment of the present application;

[0028] FIG. 8(b) is a first schematic flowchart of a preparation process for handover from NTN to TN according to an embodiment of the present application;

[0029] FIG. 8(c) is a schematic diagram of a preparation process for handover from NTN to TN according to an embodiment of the present application; Figure 2 ;

[0030] FIG. 8(d) is a schematic flowchart of a preparation process for handover from TN to NTN according to an embodiment of the present application;

[0031] Figure 9 is a schematic structural diagram of a handover device according to an embodiment of the present application;

[0032] Figure 10 is a schematic structural diagram of a communication device according to an embodiment of the present application;

[0033] Figure 11 is a schematic structural diagram of a chip according to an embodiment of the present application. Detailed implementation manners

[0034] In order to understand the features and technical content of the embodiments of the present application in more detail, the implementation of the embodiments of the present application will be described in detail below with reference to the accompanying drawings. The accompanying drawings are only for reference and explanation, and are not used to limit the embodiments of the present application.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0036] In the following description, reference is made to "some embodiments", which describe a subset of all possible embodiments. However, it is understood that "some embodiments" may be the same subset or different subsets of all possible embodiments, and may be combined with each other without conflict.

[0037] It should also be noted that the terms "first / second / third" involved in the embodiments of the present application are only used to distinguish similar objects and do not represent a specific order for the objects. It can be understood that "first / second / third" can be interchanged with a specific order or sequence when permitted, so that the embodiments of the present application described here can be implemented in an order other than that illustrated or described here.

[0038] In the embodiments of the present application, the term "and / or" is merely a description of the association relationship between associated objects, indicating that there can be three relationships. For example, object A and / or object B can represent three situations: object A exists alone, object A and object B exist simultaneously, and object B exists alone.

[0039] In addition, in the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically defined.

[0040] It should be noted that although the present text takes the inter-network handover between NTN to TN handover and TN to NTN handover as an example for illustration, the technical solutions of the embodiments of the present application are not limited thereto. The technical solutions of the embodiments of the present application can also be applied to other inter-network handovers, such as TN to TN handover and NTN to NTN handover.

[0041] In the current 3GPP R17 standard, only the enhancement of the trigger conditions for CHO is proposed for intra-satellite / inter-satellite handover, and the issue of satellite-ground inter-network handover is not considered for the time being. In the actual existing network deployment scenario, mobile terminals face the problem of service continuity between NTN and TN. The inter-network handover can be divided into two demand scenarios as follows:

[0042] Scenario 1, referring to Fig. 1(a), the terminal travels from the open sea area towards the shore, and the forward direction is the inland area with good TN coverage. It should be timely switched from NTN to TN to provide coverage services.

[0043] Scenario 2, referring to Fig. 1(b), the terminal travels from the port towards the ocean area, and the forward direction is the area covered only by NTN. It should be timely switched from TN to NTN to ensure service continuity.

[0044] The traditional handover process is as follows: The User Equipment (UE) measures the signal quality of the serving cell and neighboring cells, reports the measurement results to the source base station. The source base station makes a handover decision based on the reported results, sends a handover request to the target base station, obtains the configuration information of the target base station, and sends a Radio Resource Control Reconfiguration (RRC Reconfiguration) to the UE. A connection with the target base station is established through the RRC Reconfiguration to complete the handover.

[0045] Figure 2 It is a schematic diagram of the process of conditional handover under existing conditions. Figure 2 The network elements and devices involved are: User Equipment UE, source base station, target base station, other potential target base stations, Access and Mobility Management Function (AMF), and User Plane Function (UPF) of the UE. The following describes Figure 2 the process. Step 0: Mobility control information provided by the AMF. Step 1: Measurement control and reporting. Step 2: CHO decision. Step 3: Handover request. Step 4: Admission control. Step 5: Handover request confirmation. Step 6: RRC reconfiguration. Step 7: Completion of RRC reconfiguration. After that, the UE evaluates the CHO conditions, detaches from the old cell, and synchronizes to the new cell. Step 7a: Extremely early state transmission. Step 8: Completion of CHO. Step 8a: Successful handover. Step 8b: Serial number status transmission. Step 8c: Handover cancellation.

[0046] Figure 3(a) is a schematic diagram of the Round Trip Time (RTT) positioning process. The network elements and devices involved in Figure 3(a) are: User Equipment (UE), serving base station (serving gNB), Location Management Function (LMF), and neighboring base stations (neighboring gNBs). The following describes the process of Figure 3(a). Step 3001: The LMF notifies the UE of the Positioning Reference Signal (PRS) configurations of all gNBs participating in positioning. Subsequently, the UE receives the PRS signals of the serving gNB and neighboring gNBs at the notified locations and performs Relative Time of Arrival (RTOA) measurements. Step 3002a: The LMF notifies the serving gNB of its PRS configuration, including the period, pattern, etc. Step 3002b: The LMF notifies the neighboring gNBs of their PRS configurations, including the period, pattern, etc. Step 3003: The UE reports the measured multi-station RTOA to the LMF. Step 3004: The serving gNB notifies the UE of the Sounding Reference Signal (SRS) configuration. Step 3005: The serving gNB notifies the LMF of the SRS configuration. Step 3006: The LMF notifies the neighboring gNBs of the SRS configuration of the serving gNB. Step 3007: The UE sends SRS / SRS for positioning to the serving gNB. Step 3008a: The serving gNB receives the SRS and performs RTOA measurements. Step 3008b: The neighboring gNBs receive the SRS and perform RTOA measurements. Step 3009a: The serving gNB notifies the LMF of the measured RTOA of its own station. Step 3009b: The neighboring gNBs notify the LMF of the measured RTOA of their own stations. Step 3010: The LMF performs position calculation based on the RTOA reported by the UE and gNBs. When applied in the NTN scenario, due to the measurement results of satellite movement having UE position mirror points, which are not the true positions of the UE. The specific mirror points in the NTN scenario are shown in Figure 3(b). Because the NTN base station is mobile, a measurement is made at time T1. The NTN base station measures RTT1 at position 1. Based on RTT1, it can be determined that the UE is located on circle 3101 on the ground (the points on circle 3101 are candidate positions). RTT1 is the round-trip transmission time of the reference signal corresponding to the distance from the points on circle 3101 to position 1. A measurement is made at time T2. The NTN base station measures RTT2 at position 2. Based on RTT2, it can be determined that the UE is located on circle 3102 on the ground (the points on circle 3102 are candidate positions). RTT2 is the round-trip transmission time of the reference signal corresponding to the distance from the points on circle 3102 to position 2.Thus, the intersection points of circle 3101 and circle 3102 are the positions of the UE (one exact position and one mirror position).

[0047] In the existing satellite-terrestrial network deployment solutions, the inter-network handover between NTN and TN cells has not been considered for the time being. In the 3GPP NTN field, conditional enhancements based on CHO have been proposed for handovers within NTN cells. As a supplementary coverage for the terrestrial network, satellite-terrestrial (i.e., NTN-TN) handover is a necessary research direction. For example, the coverage continuity issue of critical services such as warships in the existing network urgently needs to be solved. For the scenario of NTN to TN handover, based on the existing CHO solution, the source NTN base station needs to wait for the UE to report the measurement results of neighboring cells, and perform resource application and handover condition configuration for candidate cells. On the one hand, the coverage area of NTN cells is relatively large and there are many neighboring cells, which will cause a large number of terrestrial base stations to reserve resources in advance, resulting in unnecessary resource waste. On the other hand, the candidate base stations do not fully consider the moving direction of the UE. Therefore, it is necessary to further narrow down the range of TN candidate cells. As shown in Figure 4(a), the candidate cells for executing CHO can be configured for the UE more accurately. For the scenario of TN to NTN handover, considering the existing CHO solution, the source TN base station needs to wait for the UE to report the measurement results of neighboring cells, and perform resource application and handover condition configuration for candidate cells. The candidate base stations do not fully consider the moving direction of the UE. As shown in Figure 4(b), it can be further enhanced based on the CHO solution, and the TN can correctly trigger the reservation of appropriate NTN resources to facilitate the rapid access of the terminal.

[0048] In order to further accurately determine the request timing of inter-network handover and reduce resource waste, the following technical solutions of the embodiments of this application are proposed.

[0049] Figure 5 It is a schematic flowchart of the handover method provided by the embodiments of this application. As shown in Figure 1, the method includes the following steps:

[0050] Step 501: The first base station obtains first information of the user equipment, and the first information includes at least one of the following: position, moving direction, speed, and acceleration.

[0051] The purpose of obtaining the UE direction is to accurately determine the initiation timing of the handover request (HANDOVER REQUEST). In some embodiments, based on an improved positioning process (such as RTT), that is, the source base station obtains the rough positioning of the UE (which may include mirror points) from the LMF or the positioning server multiple times, without the need for the accurate position of the UE.

[0052] The first base station obtains the first information of the user equipment, including:

[0053] The first base station obtains the first information of the user equipment from the server; or, the first base station obtains the first information of the user equipment based on the reference signal sent by the user equipment.

[0054] In some embodiments, the server may be a positioning server or an LMF, and the present application does not make specific limitations thereon.

[0055] The first base station obtains first information of the user equipment based on the reference signal sent by the user equipment, including:

[0056] The first base station receives the reference signal sent by the user equipment and determines the round-trip time (RTT) of the reference signal, and determines the candidate position of the user equipment based on the RTT of the reference signal;

[0057] The first base station determines at least one of the position, moving direction, speed, and acceleration of the user equipment based on the change situation of the candidate position of the user equipment.

[0058] In some embodiments, the first base station is an NTN base station. Based on the existing improved positioning process, the moving direction of the UE is obtained by switching from the NTN to the TN network. In some embodiments, taking the RTT scheme as an example, the user equipment sends reference signals to this NTN satellite multiple times. This NTN satellite measures the reception time and the transmission time to obtain the time difference RTT. The number of times of sending the reference signal is determined according to the actual situation, and the present application does not make specific limitations thereon. Here, taking the user equipment sending three reference signals to this NTN satellite as an example, how the NTN cell obtains the moving direction of the user equipment is shown in FIG. 6(a). Since the NTN base station is moving, a measurement is performed at time T1. The NTN base station measures RTT1 at position 1. According to RTT1, it can be determined that the UE is located on the circle 6001 on the ground (the points on the circle 6001 are candidate positions). RTT1 is the round-trip transmission time of the reference signal corresponding to the distance from the points on the circle 6001 to position 1. A measurement is performed at time T2. The NTN base station measures RTT2 at position 2. According to RTT2, it can be determined that the UE is located on the circle 6002 on the ground. RTT2 is the round-trip transmission time of the reference signal corresponding to the distance from the points on the circle 6002 to position 2. Thus, the intersection of the circle 6001 and the circle 6002 is the position of the UE (an accurate position and a mirror image position). A measurement is performed at time T3. The NTN base station measures RTT3 at position 3. According to RTT3, it can be determined that the UE is located on the circle 6003 on the ground. RTT3 is the round-trip transmission time of the reference signal corresponding to the distance from the points on the circle 6003 to position 3. Thus, the intersection of the circle 6002 and the circle 6003 is the position of the UE (an accurate position and a mirror image position). According to the positions of the UE obtained twice, the moving direction, speed, and acceleration of the UE can be obtained.

[0059] The first base station obtains first information of the user equipment based on the reference signal sent by the user equipment, including:

[0060] The first base station receives the reference signal sent by the user equipment and determines the RTT of the reference signal, and determines the candidate location of the user equipment based on the RTT of the reference signal;

[0061] The first base station determines at least one of the location, moving direction, speed, and acceleration of the user equipment based on the change situation of the candidate location of the user equipment and the beam where the user equipment is located.

[0062] In some embodiments, the first base station is a TN base station. Since the TN base station is fixed and the circles measured multiple times are concentric circles relative to the NTN base station, the direction cannot be obtained. Therefore, the direction can be determined by the beam, and the moving direction of the UE switching from TN to NTN can be obtained based on the existing improved positioning process. In some embodiments, how the TN cell obtains the moving direction of the user equipment is shown in FIG. 6(b). Taking the RTT + beam measurement scheme as an example, the first base station measures the UE reference signal multiple times to obtain the RTT, and the process is as described above and will not be elaborated here. Combining the first base station using the beam to estimate the UE azimuth and summarizing it to the server, thus, the first base station obtains the moving direction and speed of the UE.

[0063] The first base station obtains the first information of the user equipment from the server, including:

[0064] The first base station obtains the location of the user equipment from the server;

[0065] The method further includes: the first base station determines at least one of the moving direction, speed, and acceleration of the user equipment based on the change situation of the location of the user equipment.

[0066] In some embodiments, the first base station is an NTN base station or a TN base station. The source base station, candidate base station, or first base station sends the information related to the first information of the user equipment to the server, and the first base station obtains the information related to the first information of the user equipment from the server, and the first base station uses this information to obtain the first information of the user equipment, where the first information includes at least one of the following: the location, moving direction, speed, and acceleration of the user equipment.

[0067] Step 502: The first base station determines a candidate base station list according to the first information of the user equipment, and sends a handover request to each candidate base station in the candidate base station list.

[0068] The purpose of the CHO decision is to accurately switch the target range of the request. The source base station needs to determine whether to execute the handover decision according to the UE moving direction and speed and the geographical location of the neighboring cell, and select multiple (greater than or equal to 2) handover candidate TN cells or NTN cells for the UE.

[0069] In some embodiments, the first base station determines the selection range of candidate base stations according to the moving direction of the user equipment, determines when the user equipment moves out of the coverage range of the first base station based on the speed and acceleration of the user equipment, and further determines the time to switch to the candidate base station, that is, determines the time of the handover request.

[0070] The first base station determines a candidate base station list according to the first information of the user equipment, including:

[0071] The first base station determines a candidate base station list according to the first information of the user equipment and the location information and / or moving trajectory information of multiple neighboring base stations.

[0072] In some embodiments, the neighboring base stations are fixed, that is, the neighboring base stations are TN base stations. Then, the first base station determines the range of selecting neighboring base stations according to the moving direction of the user equipment, and further determines the candidate base station list according to the location information of the neighboring base stations.

[0073] In some embodiments, the neighboring base stations are mobile, that is, the neighboring base stations are NTN base stations. Then, the first base station determines the range of selecting neighboring base stations according to the moving direction of the user equipment, and further determines the candidate base station list according to the location information and moving trajectory information of the neighboring base stations, where the moving trajectory information of the neighboring base station is obtained from the ephemeris information of the base station.

[0074] The method further includes that the first base station determines the handover timing of the user equipment according to the first information of the user equipment and at least one of the following: the moving trajectory information of the first base station, the moving trajectory information of multiple neighboring base stations;

[0075] The first base station sends a handover command to the user equipment according to the handover timing.

[0076] In some embodiments, the handover timing refers to the timing of issuing the handover command, and the handover command carries an RRC reconfiguration message.

[0077] In some embodiments, the first base station is an NTN base station, that is, the first base station is mobile, and the neighboring base station is a TN base station, that is, switching from the NTN to the TN scenario. Then, the handover timing needs to be determined according to the moving trajectory information of the first base station. In some embodiments, the first base station is a TN base station, and the neighboring base station is an NTN base station, that is, the neighboring base station is mobile, that is, switching from the TN to the NTN scenario. Then, the handover timing needs to be determined according to the moving trajectory information of the neighboring base station. In some embodiments, if both the first base station and the neighboring base station are NTN base stations, that is, both the first base station and the neighboring base station are mobile, then the handover timing needs to be determined according to the moving trajectory information of the first base station and the neighboring base station.

[0078] In some embodiments, the first base station is an NTN base station and the neighboring base station is a TN base station. Referring to FIG. 7(a), the handover opportunity for switching from the NTN base station to the TN base station can be obtained:

[0079] Step 7001: The NTN base station determines the moving direction, speed, and acceleration of the UE through the rough positioning of the UE fed back by the positioning server multiple times.

[0080] The process of obtaining the rough positioning, moving direction, speed, and acceleration of the UE is as described above and will not be elaborated here.

[0081] Step 7002: The NTN base station determines the earliest handover opportunity of the UE in combination with the ephemeris information of the base station.

[0082] The NTN base station uses the ephemeris information of the base station to determine its moving trajectory information, and determines the earliest handover opportunity of the UE according to its moving trajectory information. The handover opportunity refers to the time when the handover command is sent. The handover command carries an RRC reconfiguration message, that is, it includes the in-position time of the candidate base station resource reconfiguration message, which affects Figure 2 Step 6 in, that is, the steps related to RRC reconfiguration.

[0083] Step 7003: The NTN base station obtains a list of TN base stations within a certain range through the moving direction of the UE, and forms a candidate base station list Target candidates(T1) at time T1.

[0084] Among them, the candidate base station list Target candidates(T1) at time T1 includes multiple candidate base stations. The obtaining process is as described above and will not be elaborated here.

[0085] Step 7004: The NTN base station sends requests CHO to Target candidates(T1).

[0086] In some embodiments, in the scenario of switching from NTN to TN, in order to switch to TN as soon as possible. Without waiting for the UE to approach the TN base station and report the TN neighboring cell report according to the measurement configuration before deciding whether to execute CHO, steps 1 in Figure 2 can be omitted, that is, the steps related to measurement control and reporting.

[0087] In some embodiments, the first base station is a TN base station and the neighboring base station is an NTN base station. Referring to FIG. 7(b), the handover opportunity for switching from the TN base station to the NTN base station can be obtained:

[0088] Step 7101: The TN base station determines the moving direction, speed, and acceleration of the UE through the rough positioning of the UE fed back by the positioning server multiple times.

[0089] The process of obtaining the rough location, moving direction, speed, and acceleration of the UE is as described above and will not be elaborated here.

[0090] Step 7102: The TN base station determines the earliest handover opportunity required by the UE in combination with the neighboring cell ephemeris information table.

[0091] The TN base station uses the ephemeris information of multiple neighboring NTN base stations to determine its movement trajectory information, and determines the earliest handover opportunity of the UE according to its movement trajectory information. The handover opportunity refers to the time when the handover command is issued. The handover command carries an RRC reconfiguration message, that is, it includes the in-position time of the candidate base station resource reconfiguration message, which affects Figure 2 Step 6 in, that is, the steps related to RRC reconfiguration.

[0092] Step 7103: The TN base station obtains a list of NTN base stations within a certain range based on the UE's traveling direction to form a candidate base station list Target candidates(T1) at time T1.

[0093] Among them, the candidate base station list Target candidates(T1) at time T1 includes multiple candidate base stations. The obtaining process is as described above and will not be elaborated here.

[0094] In some embodiments, if the candidate base station is an NTN of a ground-moving cell, the change in the NTN coverage range needs to be considered, and the TN base station needs to obtain an NTN cell with a longer remaining coverage time in the UE's moving direction.

[0095] Step 7104: The NTN base station sends requests CHO to Target candidates(T1).

[0096] In some embodiments, in the scenario of switching from TN to a ground-moving NTN, the satellite moves at a high speed. Affected by the space-ground transmission delay, there is no need to wait for the UE to approach the NTN base station and report the NTN neighbor report according to the measurement configuration before deciding whether to execute CHO, so step 1 in Figure 2 can be omitted, that is, the steps related to measurement control and reporting.

[0097] The technical solution of the embodiment of the present application proposes an inter-network handover method for satellite-ground collaborative networking. Based on the existing CHO process, an inter-network interaction scheme based on an improved positioning process is introduced to further accurately determine the resource request timing for NTN to TN or TN to NTN to initiate CHO handover, and the range of candidate TN or NTN neighboring cells to be dispatched to the user equipment. The first base station obtains the first information of the user equipment, where the first information includes at least one of the following: location, moving direction, speed, and acceleration; the first base station determines a candidate base station list according to the first information of the user equipment, and sends a handover request to each candidate base station in the candidate base station list. By introducing an improved positioning process to obtain the first information of the user equipment, the candidate base station list is determined based on this first information. In this way, a suitable candidate base station list is determined through the first information, improving the handover efficiency. At the same time, it can also reduce the problem of resource waste caused by resource reservation of a large number of candidate base stations. In addition, this conditional handover scheme can greatly reduce the preparation time for the inter-network handover of the first base station to the base stations in the candidate base station list in the existing network and improve the handover accuracy.

[0098] Based on this, a further description is made of the handover method provided by the embodiment of the present application. Figure 8(a) shows an inter-network handover method proposed by the present application for satellite-ground collaborative networking. The network elements and devices involved in Figure 8(a) are: user equipment UE, source base station, target base station, other potential target base stations, access and AMF, UPF. The following describes the process of Figure 8(a). Step 0: Mobile control information provided by AMF. Step 0.5: Obtain UE location estimation. Step 1: Measurement control and reporting. Step 2: CHO decision. Step 3: Handover request. Step 4: Admission control. Step 5: Handover request confirmation. Step 6: RRC reconfiguration. Step 7: RRC reconfiguration completed. Then the UE evaluates the CHO conditions, detaches from the old cell, and synchronizes to the new cell. Step 7a: Ultra-early state transmission. Step 8: CHO completed. Step 8a: Handover successful. Step 8b: Serial number state transmission. Step 8c: Handover cancelled. In the handover method proposed by the present application, mainly step 0.5: obtain UE location estimation is added, and the process of the improved step 2: CHO decision. The specific process of obtaining the UE location estimation and the specific process of CHO judgment are as described above and will not be elaborated here.

[0099] The technical solution of the embodiment of the present application obtains the moving direction, speed and acceleration of the user equipment based on an improved positioning scheme. The first base station applies to the terminal positioning server multiple times for the rough positioning information of the user equipment. Before (or after) the terminal measurement report, the first base station judges whether to perform the inter-network conditional handover from NTN to TN or from TN to NTN, and selects a suitable candidate base station to initiate a handover resource application. Among them, the CHO decision needs to judge the UE direction and speed based on the improved positioning process, and select multiple candidate target base stations in the forward direction of the UE to initiate a HANDOVER REQUEST. Further reduce the number of base stations reserved for resource reservation for performing CHO and reduce the handover preparation time at the same time. The subsequent processes such as handover execution do not need to be modified, that is, the candidate base station performs admission control after receiving the request and replies with a handover request acknowledgment (HANDOVER REQUEST ACKNOWLEDGE). The source base station sends the allowed candidate target base stations and handover execution conditions to the UE through RRCReconfiguration, and waits for the measurement results such as the target cell reference signal receiving power (Reference Signal Receiving Power, RSRP) to meet the execution conditions, and then the UE directly initiates a handover to the target cell. In this way, by introducing a conditional handover scheme based on an improved positioning process, the preparation time for the UE to switch between the satellite and the ground (or from the ground to the satellite) network in the existing network can be greatly reduced, and at the same time, the problem of resource waste caused by resource reservation of a large number of ground base stations can be reduced.

[0100] Based on this, a further description is made of the handover method provided by the embodiment of the present application. Referring to Figure 8(b) - Figure 8(d) As shown, the preparation process for the handover from NTN to TN and the preparation process for the handover from TN to NTN are introduced.

[0101] Referring to Figure 8(b), the NTN base station pre-selects the TN neighbor cell list according to the UE moving direction information, budgets the RRC reconfiguration message sending time, and timely initiates a HANDOVER REQUEST to the candidate base station list where the UE moving direction is located. The preparation process for the handover from NTN to TN is as follows:

[0102] Step 8100: The mobility control information provided by the AMF.

[0103] Step 8101: Obtain the UE moving direction.

[0104] Step 8102: Configure UE measurement and reporting (can be omitted).

[0105] Step 8103: Judge CHO according to the UE moving direction and determine the candidate base station list.

[0106] Step 8104: Send a handover request to the candidate base station list.

[0107] The subsequent steps are the same as the CHO process and will not be elaborated here.

[0108] The technical solution of the embodiment of this application proposes a solution for the handover preparation process from NTN to TN, obtains the UE movement direction, configures UE measurement and reporting, makes a CHO decision according to the UE movement direction, and determines a candidate base station list. The first base station sends a handover request to the candidate base station list. In this way, the preparation time for the handover from the satellite to the terrestrial network can be reduced, and at the same time, the problem of resource waste caused by resource reservation of a large number of terrestrial satellites can be reduced.

[0109] In special cases, the forward direction of the UE is different from the neighboring cell range corresponding to the current NTN cell (at T1), that is, the neighboring cell at T1 is not applicable to the target cell configuration actually required by the terminal at T2. Therefore, the consideration of its own ephemeris information needs to be included in the confirmation of the candidate base station list. As shown in Figure 8(c), the preparation process for the handover from NTN to TN is as follows:

[0110] Step 8200: Mobility control information provided by the AMF.

[0111] Step 8201: Obtain the UE movement direction at T1.

[0112] Step 8202: Configure UE measurement and reporting (can be omitted).

[0113] Step 8203: Determine whether CHO needs to be executed at T2 according to the UE movement direction and the ephemeris information of NTN, and determine the candidate base station list at T2.

[0114] Step 8204: Send a handover request to the candidate base station list.

[0115] The subsequent steps are the same as the CHO process and will not be elaborated here.

[0116] The technical solution of the embodiment of this application proposes a solution for the handover preparation process from NTN to TN, obtains the UE movement direction at T1, configures UE measurement and reporting, determines whether CHO needs to be executed at T2 according to the UE movement direction and the ephemeris information of NTN, and determines the candidate base station list at T2, and sends a handover request to the candidate base station list. In this way, the preparation time for the handover from the satellite to the terrestrial network can be reduced, and at the same time, the problem of resource waste caused by resource reservation of a large number of terrestrial satellites can be reduced.

[0117] As shown in FIG. 8(d), the TN base station pre - screens the NTN neighbor cell list according to the UE movement direction information, budgets the RRC re - configuration message sending time, and timely initiates a HANDOVER REQUEST to the candidate base station list in the UE movement direction; the preparation process for the handover from TN to NTN is as follows:

[0118] Step 8300: Mobility control information provided by the AMF.

[0119] Step 8301: Obtain the UE movement direction.

[0120] Step 8302: Configure UE measurement and reporting (can be omitted).

[0121] Step 8303: Judge CHO according to the UE movement direction and determine the candidate base station list.

[0122] Step 8304: Send a handover request to the candidate base station list.

[0123] The subsequent steps are the same as the CHO process and will not be elaborated here.

[0124] The technical solution of the embodiment of the present application proposes a solution for the preparation process of handover from NTN to TN, obtains the UE movement direction, configures UE measurement and reporting, makes a CHO decision according to the UE movement direction, and determines the candidate base station list. The first base station sends a handover request to the candidate base station group. In this way, the preparation time for the handover from the satellite to the ground network can be reduced, and at the same time, the problem of a large amount of resource waste caused by resource reservation of ground satellites can be reduced.

[0125] The preferred embodiments of the present application have been described in detail above with reference to the accompanying drawings. However, the present application is not limited to the specific details in the above - mentioned embodiments. Within the technical concept scope of the present application, various simple modifications can be made to the technical solution of the present application, and these simple modifications all belong to the protection scope of the present application. For example, in the above - mentioned specific embodiments, the various specific technical features described can be combined in any appropriate way without contradiction. To avoid unnecessary repetition, the present application does not separately describe various possible combination methods. Also, for example, any combination can be made between the various different embodiments of the present application as long as it does not violate the idea of the present application, and it should also be regarded as the content disclosed by the present application. Also, for example, on the premise of no conflict, the various embodiments and / or the technical features in the various embodiments described in the present application can be combined with the prior art arbitrarily, and the technical solutions obtained after combination should also fall within the protection scope of the present application.

[0126] It should be understood that in various method embodiments of the present application, the magnitudes of the serial numbers of the above processes do not imply the sequence of execution. The execution sequence of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0127] Based on the same inventive concept as the foregoing embodiments, Figure 9 is a schematic structural diagram of a handover device provided by an embodiment of the present application. The handover device is applied to a first base station, such as Figure 9 as shown, the handover device includes:

[0128] An obtaining unit 901: configured to obtain first information of a user equipment, where the first information includes at least one of the following: location, moving direction, speed, and acceleration.

[0129] A determining unit 902: configured to determine a list of candidate base stations according to the first information of the user equipment.

[0130] A sending unit 903: configured to send a handover request to each candidate base station in the list of candidate base stations.

[0131] In some embodiments, the obtaining unit 901: is further configured to obtain the first information of the user equipment from a server; or, obtain the first information of the user equipment based on a reference signal sent by the user equipment.

[0132] In some embodiments, the device further includes a receiving unit 904.

[0133] In some embodiments, the receiving unit 904 is configured to receive a reference signal sent by the user equipment; the determining unit 902: is further configured to determine the round-trip time RTT of the reference signal, determine a candidate position of the user equipment based on the RTT of the reference signal; and determine at least one of the location, moving direction, speed, and acceleration of the user equipment based on the change condition of the candidate position of the user equipment.

[0134] In some embodiments, the receiving unit 904 is configured to receive a reference signal sent by the user equipment; the determining unit 902: is further configured to determine the RTT of the reference signal, determine a candidate position of the user equipment based on the RTT of the reference signal; and determine at least one of the location, moving direction, speed, and acceleration of the user equipment based on the change condition of the candidate position of the user equipment and the beam where the user equipment is located.

[0135] In some embodiments, the obtaining unit 901: is further configured to obtain the location of the user equipment from a server.

[0136] In some embodiments, the determining unit 902: is further configured to determine at least one of the moving direction, speed, and acceleration of the user equipment based on the change condition of the location of the user equipment.

[0137] In some embodiments, the determining unit 902 is further configured to determine a list of candidate base stations according to the first information of the user equipment and the location information and / or the movement trajectory information of a plurality of neighboring base stations.

[0138] In some embodiments, the determining unit 902 is further configured to determine the handover timing of the user equipment according to the first information of the user equipment and at least one of the following: the movement trajectory information of the first base station, the movement trajectory information of a plurality of neighboring base stations.

[0139] In some embodiments, the sending unit 903 is further configured to send a handover command to the user equipment according to the handover timing.

[0140] Those skilled in the art should understand that Figure 9 The implementation functions of the units in the shown secure transmission signaling device can be understood with reference to the relevant descriptions of the foregoing methods. Figure 9 The functions of the units in the shown secure transmission signaling device can be implemented by a program running on a processor or by specific logic circuits.

[0141] Figure 10 is a schematic structural diagram of a communication device 1000 provided by an embodiment of the present application. Figure 10 The shown communication device 1000 includes a processor 1001, and the processor 1001 can call and run a computer program from a memory to implement the method in the embodiment of the present application.

[0142] Optionally, as Figure 10 shown, the communication device 1000 may further include a memory 1002. Wherein, the processor 1001 can call and run a computer program from the memory 1002 to implement the method in the embodiment of the present application.

[0143] Wherein, the memory 1002 can be a separate device independent of the processor 1001 or integrated in the processor 1001.

[0144] Optionally, as Figure 10 shown, the communication device 1000 may further include a transceiver 1003, and the processor 1001 can control the transceiver 1003 to communicate with other devices. Specifically, the processor 1001 can send information or data to other devices or receive information or data sent by other devices.

[0145] Wherein, the transceiver 1003 can include a transmitter and a receiver. The transceiver 1003 may further include antennas, and the number of antennas can be one or more.

[0146] The communication device 1000 can specifically be the first base station in the embodiments of this application, and the communication device 1000 can implement the corresponding processes implemented by the first base station in the various methods of the embodiments of this application. For the sake of brevity, details are not described herein again.

[0147] Figure 11 It is a schematic structural diagram of the chip in the embodiments of this application. Figure 11 The illustrated chip 1100 includes a processor 1101. The processor 1101 can call and run a computer program from a memory to implement the methods in the embodiments of this application.

[0148] Optionally, as Figure 11 shown, the chip 1100 may further include a memory 1102. Among them, the processor 1101 can call and run a computer program from the memory 1102 to implement the methods in the embodiments of this application.

[0149] Among them, the memory 1102 can be a separate device independent of the processor 1101, or can be integrated in the processor 1101.

[0150] Optionally, the chip 1100 may further include an input interface 1103. Among them, the processor 1101 can control the input interface 1103 to communicate with other devices or chips. Specifically, it can obtain information or data sent by other devices or chips.

[0151] Optionally, the chip 1100 may further include an output interface 1104. Among them, the processor 1101 can control the output interface 1104 to communicate with other devices or chips. Specifically, it can output information or data to other devices or chips.

[0152] The chip can be applied to the first base station in the embodiments of this application, and the chip can implement the corresponding processes implemented by the first base station in the various methods of the embodiments of this application. For the sake of brevity, details are not described herein again.

[0153] It should be understood that the chip mentioned in the embodiments of this application can also be referred to as a system-on-chip, system chip, chip system, or system-on-chip, etc.

[0154] It should be understood that the processor in the embodiments of the present application may be an integrated circuit chip with signal processing capabilities. In the implementation process, the steps of the above method embodiments can be completed by the integrated logic circuit in the hardware of the processor or instructions in the form of software. The above-mentioned processor may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. It can implement or execute the various methods, steps and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as being executed by the hardware decoding processor, or executed by a combination of the hardware and software modules in the decoding processor. The software module may be located in a mature storage medium in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. This storage medium is located in the memory, and the processor reads the information in the memory and combines its hardware to complete the steps of the above method.

[0155] It can be understood that the memory in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchlink dynamic random access memory (SLDRAM), and direct rambus random access memory (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include but not be limited to these and any other suitable types of memory.

[0156] It should be understood that the above memory is by way of example but not limitation. For example, the memory in the embodiments of the present application can also be a static random access memory (SRAM), a dynamic random access memory (DRAM), a synchronous dynamic random access memory (SDRAM), a double data rate SDRAM (DDR SDRAM), an enhanced SDRAM (ESDRAM), a synch link DRAM (SLDRAM), and a direct rambus random access memory (DR RAM), etc. That is to say, the memory in the embodiments of the present application is intended to include but not be limited to these and any other suitable types of memory.

[0157] The embodiments of the present application also provide a computer-readable storage medium for storing a computer program. The computer-readable storage medium can be applied to the first base station in the embodiments of the present application, and the computer program enables the computer to execute the corresponding processes implemented by the first base station in the various methods of the embodiments of the present application. For the sake of brevity, details are not described herein again.

[0158] Those of ordinary skill in the art can realize that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0159] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments, and details are not described herein again.

[0160] In several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there can be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed mutual coupling, direct coupling, or communication connection can be through some interfaces. The indirect coupling or communication connection of the devices or units can be in an electrical, mechanical, or other form.

[0161] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place, or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0162] In addition, the functional units in the various embodiments of the present application can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit.

[0163] When the above-mentioned functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of this application. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs.

[0164] As described above, the above is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed by this application can easily think of changes or substitutions, and all should be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A handover method, characterized in that, the method comprises: A first base station obtains first information of a user equipment, where the first information includes at least one of the following: location, moving direction, speed, and acceleration; The first base station determines a candidate base station list according to the first information of the user equipment, and sends a handover request to each candidate base station in the candidate base station list.

2. The method according to claim 1, characterized in that, the first base station obtaining the first information of the user equipment includes: The first base station obtains the first information of the user equipment from a server; or, The first base station obtains the first information of the user equipment based on a reference signal sent by the user equipment.

3. The method according to claim 2, characterized in that, the first base station obtaining the first information of the user equipment based on the reference signal sent by the user equipment includes: The first base station receives the reference signal sent by the user equipment and determines the round-trip time (RTT) of the reference signal, and determines candidate positions of the user equipment based on the RTT of the reference signal; The first base station determines at least one of the location, moving direction, speed, and acceleration of the user equipment based on a change condition of the candidate positions of the user equipment.

4. The method according to claim 2, characterized in that, the first base station obtaining the first information of the user equipment based on the reference signal sent by the user equipment includes: The first base station receives the reference signal sent by the user equipment and determines the RTT of the reference signal, and determines candidate positions of the user equipment based on the RTT of the reference signal; The first base station determines at least one of the location, moving direction, speed, and acceleration of the user equipment based on a change condition of the candidate positions of the user equipment and a beam where the user equipment is located.

5. The method according to claim 2, characterized in that, the first base station obtaining the first information of the user equipment from the server includes: The first base station obtains the location of the user equipment from the server; The method further comprises: the first base station determines at least one of the moving direction, speed, and acceleration of the user equipment based on a change condition of the location of the user equipment.

6. The method according to any one of claims 1 to 5, characterized in that, the first base station determining the candidate base station list according to the first information of the user equipment includes: The first base station determines the candidate base station list according to the first information of the user equipment and location information and / or moving trajectory information of a plurality of neighboring base stations.

7. The method according to any one of claims 1 to 5, characterized in that, the method further comprises: The first base station determines a handover opportunity of the user equipment according to the first information of the user equipment and at least one of the following: moving trajectory information of the first base station, moving trajectory information of a plurality of neighboring base stations; The first base station sends a handover command to the user equipment according to the handover opportunity.

8. A handover device, characterized in that, applied to a first base station, the device comprises: An obtaining unit, configured to obtain first information of a user device, where the first information includes at least one of the following: location, moving direction, speed, and acceleration; A determining unit, configured to determine a candidate base station list according to the first information of the user device; A sending unit, configured to send a handover request to each candidate base station in the candidate base station list.

9. A communication device, characterized in that, it includes: a processor and a memory, where the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the method according to any one of claims 1 to 7.

10. A chip, characterized in that, it includes: a processor, configured to call and run a computer program from a memory, so that a device installed with the chip executes the method according to any one of claims 1 to 7.

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