Source base station and transmission method

Abstract

A source base station and a transmission method. A source base station transmits a radio resource control reconfiguration message to a user equipment. The radio resource control reconfiguration message includes an indication message and a candidate base station list, and the candidate base station list is used for indicating a plurality of candidate base stations. The source base station determines a non-target base station among the plurality of candidate base stations based on a prediction report received from the user equipment. And the source base station transmits a handover cancellation request to the non-target base station in the plurality of candidate base stations, so that the non-target base station releases a reserved resource corresponding to the user equipment. The transmission technology provided by the invention can improve the resource use efficiency of the mobile communication system.

Description

Technical Field

[0001] This case relates to a source base station and a transmission method. Specifically, this case relates to a source base station and a transmission method that can improve the efficiency of mobile communication network resource utilization. Background Technology

[0002] In existing traditional handover (HO) operations, the handover is still triggered by the user equipment's measurement reports and the source gNB's decisions, when the signal strength reaches a threshold. However, this method requires very precise threshold setting; even slight errors can easily lead to premature or late handover, and can also cause handover failure and service interruption.

[0003] In existing technologies, Conditional Handover (CHO) has been proposed. The source base station evaluates the user equipment's measurement report, requests resource reservations from potential candidate base stations in advance, and informs the user equipment of the handover conditions for each candidate base station. The user equipment can then automatically perform the handover if any candidate base station meets the handover conditions. Conditional Handover effectively reduces the probability of handover failure and improves the smoothness of user equipment handover.

[0004] However, according to current handover specifications, the source base station requests multiple potential candidate base stations to reserve resources in advance to ensure continuous connection and service quality for user equipment (UE) during migration. In this case, these reserved resources must remain occupied until the UE actually switches over. The UE will only initiate the handover process when it detects that a candidate base station meets the handover conditions. In other words, all potential candidate base stations reserve resources awaiting UE handover, and only after successful handover will the UE receive notification from the source base station to release the resources.

[0005] The trend of 5G / 6G network densification will lead to frequent handover of user equipment; and the current handover operation specifications for the release of reserved resources for candidate base stations will affect the overall system performance, such as connection capacity.

[0006] In view of this, how to provide a source base station and transmission method that can improve the efficiency of mobile communication network resource utilization is an urgent goal for the industry. Summary of the Invention

[0007] One object of this invention is to provide a source base station. The source base station includes a transceiver interface and a processor. The transceiver interface is communicatively connected to a user equipment (UE) and a plurality of candidate base stations. The processor is electrically connected to the transceiver interface. The processor transmits a Radio Resource Control (RRC) reconfiguration message to the UE, wherein the RRC reconfiguration message includes an indication message and a list of candidate base stations, and the list of candidate base stations indicates the plurality of candidate base stations. Based on a prediction report received from the UE, the processor determines a non-target base station among the plurality of candidate base stations, wherein the prediction report is generated based on the indication message. The processor transmits a handover cancellation request to the non-target base station among the plurality of candidate base stations, causing the non-target base station to release a reserved resource corresponding to the UE.

[0008] In one embodiment of the present invention, the indication message includes a decision indication, and determining the non-target base station further includes the following operations: determining whether the indication message corresponds to a user equipment decision indication; and in response to the indication message corresponding to the user equipment decision indication, determining the non-target base station among the plurality of candidate base stations based on a first predicted base station indicated in the prediction report.

[0009] In one embodiment of the present invention, the prediction report includes a predicted signal change corresponding to each of the plurality of candidate base stations and the first predicted base station, and the determination of the non-target base station further includes the following operations: in response to the indication message corresponding to the user equipment decision indication, generating a prediction confidence value corresponding to the first predicted base station based on the predicted signal change of each of the plurality of candidate base stations; and in response to the prediction confidence value being less than a threshold value, determining the first predicted base station as the non-target base station.

[0010] In one embodiment of the present invention, the prediction report includes a predicted signal change corresponding to each of the plurality of candidate base stations and the first predicted base station, and determining the non-target base station further includes the following operations: receiving base station status information from each of the plurality of candidate base stations; generating a prediction confidence value corresponding to the first predicted base station based on the predicted signal change corresponding to each of the plurality of candidate base stations and the base station status information of each of the plurality of candidate base stations; and determining the first predicted base station as the non-target base station in response to the prediction confidence value being less than a threshold value.

[0011] In one embodiment of the present invention, the prediction report includes a predicted signal change corresponding to each of the plurality of candidate base stations, and determining the non-target base station further includes the following operations: selecting a second predicted base station from the plurality of candidate base stations based on the predicted signal change corresponding to each of the plurality of candidate base stations; and designating the second predicted base station as the non-target base station.

[0012] In one embodiment of the present invention, the processor further performs the following operations: receiving base station status information from each of the plurality of candidate base stations; selecting a second predicted base station from the plurality of candidate base stations based on the predicted signal changes corresponding to each of the plurality of candidate base stations and the base station status information of each of the plurality of candidate base stations; and designating the second predicted base station as the non-target base station.

[0013] In one embodiment of the present invention, the base station status information includes a load status and a current location.

[0014] In one embodiment of the invention, the prediction report is generated by the user equipment performing the following operations: measuring a trajectory message of the user equipment; and generating the prediction report based on a historical signal sequence value of each of the plurality of candidate base stations and the trajectory message of the user equipment.

[0015] In one embodiment of the present invention, the trajectory message includes a spatial location, a direction of movement, and a speed of movement of the user equipment.

[0016] In one embodiment of the invention, the processor further performs the following operations: receiving a handover success message from a target base station; and in response to receiving the handover success message from the target base station, transmitting a state transition message to the target base station, wherein the state transition message includes a sequence number.

[0017] In one embodiment of the present invention, the plurality of candidate base stations in the candidate base station list are generated by the source base station performing a conditional handover decision operation, and the processor further performs the following operations: receiving a handover request confirmation message from each of the plurality of candidate base stations; and generating the radio resource control reconfiguration message based on the plurality of handover request confirmation messages.

[0018] In one embodiment of the present invention, the indication message includes a decision indication, a prediction parameter indication, and an output type indication.

[0019] Another objective of this invention is to provide a transmission method for a source base station communicatively connected to a user equipment and a plurality of candidate base stations. The transmission method includes the following steps: transmitting a Radio Resource Control (RRC) reconfiguration message to the user equipment, wherein the RRC reconfiguration message includes an indication message and a list of candidate base stations, the list of candidate base stations indicating the plurality of candidate base stations; determining a non-target base station among the plurality of candidate base stations based on a prediction report received from the user equipment, wherein the prediction report is generated based on the indication message; and transmitting a handover cancellation request to the non-target base station among the plurality of candidate base stations, causing the non-target base station to release a reserved resource corresponding to the user equipment.

[0020] In one embodiment of the present invention, the indication message includes a decision indication, and determining the non-target base station further includes the following steps: determining whether the indication message corresponds to a user equipment decision indication; and in response to the indication message corresponding to the user equipment decision indication, determining the non-target base station among the plurality of candidate base stations based on a first predicted base station indicated in the prediction report.

[0021] In one embodiment of the present invention, the prediction report includes a predicted signal change corresponding to each of the plurality of candidate base stations and the first predicted base station, and determining the non-target base station further includes the following steps: in response to the indication message corresponding to the user equipment decision indication, generating a prediction confidence value corresponding to the first predicted base station based on the predicted signal change of each of the plurality of candidate base stations; and in response to the prediction confidence value being less than a threshold value, determining the first predicted base station as the non-target base station.

[0022] In one embodiment of the present invention, the prediction report includes a predicted signal change corresponding to each of the plurality of candidate base stations and the first predicted base station, and determining the non-target base station further includes the following steps: receiving base station status information from each of the plurality of candidate base stations; generating a prediction confidence value corresponding to the first predicted base station based on the predicted signal change corresponding to each of the plurality of candidate base stations and the base station status information of each of the plurality of candidate base stations; and determining the first predicted base station as the non-target base station in response to the prediction confidence value being less than a threshold value.

[0023] In one embodiment of the present invention, the prediction report includes a predicted signal change corresponding to each of the plurality of candidate base stations, and determining the non-target base station further includes the following steps: selecting a second predicted base station from the plurality of candidate base stations based on the predicted signal change corresponding to each of the plurality of candidate base stations; and designating the second predicted base station as the non-target base station.

[0024] In one embodiment of the present invention, the transmission method further includes the following steps: receiving base station status information from each of the plurality of candidate base stations; selecting a second predicted base station from the plurality of candidate base stations based on the predicted signal changes corresponding to each of the plurality of candidate base stations and the base station status information of each of the plurality of candidate base stations; and using the second predicted base station as the non-target base station.

[0025] In one embodiment of the present invention, the prediction report is generated by the user equipment performing the following steps: measuring a trajectory message of the user equipment; and generating the prediction report based on a historical signal sequence value of each of the plurality of candidate base stations and the trajectory message of the user equipment.

[0026] In one embodiment of the present invention, the trajectory message includes a spatial location, a direction of movement, and a speed of movement of the user equipment.

[0027] The transmission technology disclosed herein (including at least a source base station and a method) involves the source base station actively transmitting a radio resource control reconfiguration message containing an indication message and a list of candidate base stations to a user equipment (UE), enabling the UE to generate a corresponding prediction report based on the indication message. Subsequently, the source base station can determine a non-target base station from among the plurality of candidate base stations based on the prediction report received from the UE. Accordingly, the source base station can transmit a handover cancellation request to the non-target base station among the plurality of candidate base stations in advance, causing the non-target base station to release reserved resources corresponding to the UE. Because the transmission technology disclosed herein can notify non-target base stations to release reserved resources in advance, the resource utilization efficiency of the mobile communication system can be improved.

[0028] The following detailed description of the technology and implementation methods of this invention, in conjunction with the accompanying drawings, is provided so that those skilled in the art to which this invention pertains can understand the technical features of the claimed invention. Attached Figure Description

[0029] Figure 1 It is a schematic diagram depicting the architecture of a mobile communication system;

[0030] Figure 2 It is a schematic diagram depicting the architecture of a base station;

[0031] Figure 3 It is a schematic diagram depicting the architecture of user equipment;

[0032] Figure 4 This is a partial flowchart depicting one embodiment of this case;

[0033] Figure 5 This is a partial flowchart depicting one embodiment of this case;

[0034] Figure 6 It is a sequence diagram depicting one embodiment of this case; and

[0035] Figure 7 This is a flowchart illustrating another implementation of this invention.

[0036] [Symbol Explanation]

[0037] 1: Mobile communication system

[0038] UE: User Equipment

[0039] SgNB: Source Base Station

[0040] CgNB1, CgNB2, ..., CgNBn: Candidate base stations

[0041] 21: Send / Receive Interface

[0042] 23: Processor

[0043] 31: Send / Receive Interface

[0044] 33: Processor

[0045] 35: Positioning equipment

[0046] 400: Partial Flowchart

[0047] OP401, OP403, OP405, OP407, OP409, OP411: Operation

[0048] 500: Partial Flowchart

[0049] OP501, OP503, OP505, OP506, OP507, OP509, OP511: Operation

[0050] 600: Flowchart

[0051] CHOD: Conditional Transfer Decision

[0052] HOR: Request for Transfer

[0053] CAC: Call Access Control

[0054] HOR_ACK: Response to the handover request

[0055] RRCR: Radio Resource Control Reconfiguration Message

[0056] RRCRC: Radio Resource Control reconfiguration complete message

[0057] MP: Measurement and Prediction

[0058] PR: Forecast Report

[0059] CD: Cancel the decision

[0060] HOC: Transfer Cancellation Request

[0061] RR: Resource Release

[0062] CHOC: Conditions handover complete

[0063] HOS: Handover successful

[0064] SST: Serial Number State Transition

[0065] 700: Transmission Method

[0066] S701, S703, S705: Steps Detailed Implementation

[0067] The following will explain the source base station and transmission method provided in this application through implementation methods. However, these implementation methods are not intended to limit the implementation of this application to any environment, application, or manner described in these implementation methods. Therefore, the description of the implementation methods is for illustrative purposes only and is not intended to limit the scope of this application. It should be understood that in the following implementation methods and drawings, elements not directly related to this application have been omitted and are not shown, and the dimensions of each element and the dimensional ratio between elements are only illustrative and are not intended to limit the scope of this application.

[0068] First, let me explain the applicable scenario of one embodiment of this disclosure, the schematic diagram of which is depicted in Figure 1 .like Figure 1 As shown, the mobile communication system 1 includes a user equipment (UE), a source base station (SgNB, abbreviated as SgNB), and multiple candidate base stations (CgNB1, CgNB2, ..., CgNBn, abbreviated as CgNB), where n is a positive integer.

[0069] In the scenario described, the source base station SgNB is communicatively connected to the user equipment UE, and the source base station SgNB is communicatively connected to the candidate base stations CgNB1, CgNB2, ..., CgNBn.

[0070] It should be noted that the source base station SgNB and candidate base stations CgNB1, CgNB2, ..., CgNBn are base stations providing network services (e.g., base stations in 5G or 6G networks). In this disclosure, the source base station SgNB refers to the base station currently serving the user equipment (UE). Additionally, the candidate base stations CgNB1, CgNB2, ..., CgNBn are base stations expected to be ready for handover (e.g., base stations near the UE or located on the UE's path).

[0071] In the aforementioned scenario, the source base station SgNB provides candidate base stations CgNB1, CgNB2, ..., CgNBn to the user equipment UE, so that the user equipment UE can perform handover operations after determining the target base station. It should be noted that this application does not limit the number of candidate base stations in the mobile communication system 1 (i.e., the number of candidate base stations that are communicatively connected to the source base station SgNB).

[0072] In this embodiment, the architecture diagram of the base station is depicted in... Figure 2 (Taking the source base station SgNB and the candidate base station CgNBn as an example). The source base station SgNB and the candidate base station CgNBn each include at least a transceiver interface 21 and a processor 23, with the processor 23 electrically connected to the transceiver interface 21.

[0073] Furthermore, in this embodiment, the architecture diagram of the user equipment (UE) is depicted in... Figure 3 The user equipment (UE) includes a transceiver interface 31, a processor 33, and a positioning device 35, with the processor 33 electrically connected to the transceiver interface 31 and the positioning device 35.

[0074] It should be noted that the aforementioned Figure 2 and Figure 3 The examples shown are only of the source base station SgNB, candidate base station CgNBn, and user equipment UE, which are relevant to the operation of this invention. It should be understood that in actual operation, the base station SgNB, candidate base station CgNBn, and user equipment UE may still include other components necessary for operation (e.g., communication-related equipment, memory, inertial sensors, display screens, and other transceiver interfaces).

[0075] It should be noted that transceiver interfaces 21 and 31 are interfaces capable of receiving and transmitting data, or other interfaces capable of receiving and transmitting data that are known to those skilled in the art to which this application pertains. Transceiver interfaces 21 and 31 can receive data from sources such as external devices, external web pages, external applications, etc. Processors 23 and 33 can be various processing units, central processing units (CPUs), microprocessors, or other computing devices known to those skilled in the art to which this application pertains. Positioning device 35 can be any device with positioning functionality, such as a Global Positioning System (GPS), a WiFi positioning device, etc.

[0076] To briefly explain the purpose of this disclosure, the source base station (SgNB) can determine non-target base stations with a low probability of handover based on the status reported by the user equipment (UE) (e.g., trajectory, connection quality, etc.). Accordingly, the source base station (SgNB) can notify candidate base stations of the resource release time in advance, allowing candidate base stations with a low probability of handover to release reserved resources ahead of time, without waiting for successful UE handover. This improves the efficiency of resource utilization in mobile communication systems.

[0077] To facilitate understanding, the operation stages of the first embodiment of this disclosure will be explained first. Specifically, the operation of this disclosure can be divided into five stages, namely (1) triggering user equipment (UE) prediction stage, (2) UE prediction stage, (3) UE reporting prediction results stage, (4) source base station (SgNB) operation stage, and (5) condition handover procedure stage. The following paragraphs will describe the operation of each stage in detail.

[0078] The following will explain the specific operation of (1) triggering the prediction phase of the user equipment (UE). First, in this embodiment, the processor 23 of the source base station SgNB can notify the user equipment (UE) to start the prediction operation by including an indication message in the Radio Resource Control Reconfiguration (RRCR) message.

[0079] Specifically, the processor 23 transmits a radio resource control reconfiguration message to the user equipment (UE), wherein the radio resource control reconfiguration message includes an indication message and a candidate base station list, and the candidate base station list is used to indicate multiple candidate base stations (e.g., candidate base stations CgNB1, CgNB2, ..., CgNBn).

[0080] In some implementations, the indication message includes a decision indication, a prediction parameter indication, and an output type indication. For example, the decision indication is used to indicate whether the user equipment (UE) participates in the decision-making process or whether the source base station (SgNB) makes the decision itself.

[0081] Additionally, the prediction parameter indicator is used to specify the prediction parameters that need to be included. For example, the prediction parameters may include one or a combination of the measurement time, the measurement time interval, the number of measurements, the prediction time, and the prediction time interval.

[0082] Additionally, the output type indicator can be used to specify the format of the forecast and decision output. For example, the output type indicator can include one or a combination of the quantity of the forecast, the type of decision outcome (e.g., probability or yes / no).

[0083] It should be noted that instruction messages can be designed as IEs (information elements) so that they can be carried within control messages, such as the RRC Reconfiguration message.

[0084] In some implementations, these candidate base stations in the candidate base station list are generated by the source base station SgNB performing conditional handover decision operations.

[0085] In some implementations, the processor 23 receives handover request confirmation messages from each of these candidate base stations. Then, based on these handover request confirmation messages, the processor 23 generates radio resource control reconfiguration messages.

[0086] The following will explain the specific operation of (2) the User Equipment (UE) prediction phase.

[0087] In this embodiment, the User Equipment (UE) generates a prediction report based on the indication message contained in the Radio Resource Control (RRC) reconfiguration message. For example, the UE collects the data to be observed according to the prediction parameters indicated in the indication message. The UE can generate the prediction report using AI / ML, such as LSTM or RNN models. As another example, the UE can predict signal changes in the near future (e.g., RSRP, RSRQ, etc.) based on the output type indication and adjust the format of the prediction output.

[0088] In addition, the User Equipment (UE) determines whether to participate in the decision-making process based on the decision indication in the indication message. If further decision-making is required, the UE can analyze the signal predicted in the previous step using AI / ML (e.g., RL model, DRL model) and output the probability (probability, yes / no, etc.) of each candidate base station in a short period of time according to the output type indication.

[0089] Specifically, the User Equipment (UE) can train a prediction model by collecting historical measurement signal information (e.g., RSRP, RSRQ, UE speed, direction, time, location characteristics, etc.) as a training dataset. For example, the trained prediction model can predict the RSRP or RSRQ value of the UE at a future point in time / time interval.

[0090] In addition, the user equipment (UE) can use historical measurement signal information and judgment results (e.g., the handover results of the UE to each candidate base station) as training datasets to train the judgment model.

[0091] For example, the User Equipment (UE) can input the historical RSRP / RSRQ values ​​of each candidate base station and the source base station as input to the judgment model. Additionally, the UE can input its current signal status (e.g., UE speed, location, and handover history records) as auxiliary features. Based on this, the trained judgment model can determine the handover probability corresponding to each candidate base station.

[0092] In some implementations, the prediction report may also include trajectory information of the user equipment (UE). The UE and the source base station (SgNB) can further use the trajectory information to determine non-target base stations with a lower probability of future handover (e.g., the closer the trajectory is to the candidate base station, the higher the probability of handover; conversely, the farther the trajectory is from the candidate base station, the lower the probability of handover).

[0093] Specifically, the User Equipment (UE) measures the UE's trajectory information. Then, based on a historical signal sequence value of each of these candidate base stations and the UE's trajectory information, the UE generates a prediction report.

[0094] In some implementations, the trajectory message includes the spatial location, direction of movement, and speed of movement of the user equipment (UE).

[0095] The following will explain the specific operation of (3) the User Equipment (UE) return prediction result stage and (4) the source base station (SgNB) operation stage.

[0096] In this embodiment, the processor 23 determines the non-target base station among these candidate base stations based on the prediction report received from the user equipment (UE), wherein the prediction report is generated based on the indication message.

[0097] It should be noted that the non-target base stations disclosed herein can be decided by the User Equipment (UE) or by the source base station (SgNB) itself. Furthermore, in some embodiments, the source base station (SgNB) can determine multiple non-target base stations at once and perform corresponding resource release operations.

[0098] The following will first describe the implementation method for user equipment (UE) participation in decision-making. For ease of understanding, please refer to [link / reference needed]. Figure 4Partial flowchart 400. In this example, the User Equipment (UE) executes operation OP401 to receive prediction parameter instructions. Next, the UE executes operation OP403 to measure the signal and perform signal prediction. Then, the UE executes operation OP405 to determine whether the decision should be made by the UE. If the result is no, the UE executes operation OP407 to transmit a prediction report to the source base station SgNB. If the result is yes, the UE executes operation OP409 to determine the handover probability of these candidate base stations. Finally, the UE executes operation OP411 to transmit a prediction report containing the decision result to the source base station SgNB.

[0099] In some implementations, the indication message includes a decision indication. The processor 23 determines whether the indication message corresponds to a user equipment decision indication. Then, in response to the indication message corresponding to a user equipment decision indication, the processor 23 determines the non-target base station among these candidate base stations based on the first predicted base station indicated in the prediction report (i.e., the non-target base station predicted by the user equipment UE).

[0100] In some implementations, the prediction report generated by the user equipment (UE) can simultaneously indicate multiple non-target base stations.

[0101] In some implementations, the source base station SgNB can review the prediction results from the user equipment (UE) to determine whether to designate the first predicted base station as a non-target base station. Specifically, the prediction report includes the predicted signal changes corresponding to each of the candidate base stations and the first predicted base station. In response to the indication message corresponding to the UE decision indication, the processor 23 generates a prediction confidence value for the first predicted base station based on the predicted signal changes of each of the candidate base stations. Then, in response to the prediction confidence value being less than a threshold value, the processor 23 determines that the first predicted base station is a non-target base station.

[0102] In some implementations, the source base station SgNB can determine whether to designate the first predicted base station as a non-target base station based on the status of candidate base stations (e.g., load status, location, etc.). Specifically, the prediction report includes the predicted signal changes corresponding to each of these candidate base stations and the first predicted base station. The processor 23 receives base station status information from each of these candidate base stations. Then, based on the predicted signal changes corresponding to each of these candidate base stations and the base station status information of each of these candidate base stations, the processor 23 generates a prediction confidence value corresponding to the first predicted base station. Finally, in response to the prediction confidence value being less than a threshold value, the processor 23 determines that the first predicted base station is a non-target base station.

[0103] In some implementations, the base station status information includes load status and current location.

[0104] The following will first describe the implementation method of decision-making by the source base station SgNB.

[0105] In some implementations, the source base station SgNB can directly determine the non-target base station based on the prediction report returned by the user equipment UE. Specifically, the prediction report includes the predicted signal changes corresponding to each of these candidate base stations. Based on the predicted signal changes corresponding to each of these candidate base stations, the processor 23 selects a second predicted base station (i.e., the non-target base station predicted by the source base station SgNB) from these candidate base stations. Then, the processor 23 designates the second predicted base station as the non-target base station.

[0106] In some implementations, the source base station SgNB can determine whether to designate the second predicted base station as a non-target base station based on the status of candidate base stations (e.g., load status, location, etc.). Specifically, the processor 23 receives base station status information from each of these candidate base stations. Then, the processor 23 selects the second predicted base station from these candidate base stations based on the predicted signal changes corresponding to each of these candidate base stations and the base station status information of each of these candidate base stations. Finally, the processor 23 designates the second predicted base station as a non-target base station.

[0107] It should be noted that the forecast report can be designed as an IE (information element) so that it can be carried in control messages, such as a measurement report message.

[0108] Finally, in this embodiment, after determining the non-target base station, the source base station SgNB can notify the candidate base stations that belong to the non-target base station to release the reserved resources. Specifically, the processor 23 transmits a handover cancellation request to the non-target base station among these candidate base stations, so that the non-target base station releases the reserved resources of the corresponding user equipment (UE).

[0109] It should be noted that after the processor 23 transmits the handover cancellation request to the non-target base station among these candidate base stations, the source base station SgNB, user equipment UE and other candidate base stations can continue to execute the aforementioned (5) conditional handover procedure phase.

[0110] For easier understanding, please refer to Figure 5Partial flowchart 500. In this example, processor 23 executes operation OP501 to determine whether the source base station SgNB should make the decision. If the result is yes, processor 23 executes operation OP503, and the source base station SgNB performs signal prediction. Next, processor 23 executes operation OP505, and the source base station SgNB receives the prediction report from the user equipment UE. Next, processor 23 executes operation OP507, and the source base station SgNB makes the decision. Next, processor 23 executes operation OP509, and the source base station SgNB transmits a handover cancellation request to non-target base stations. Then, these candidate base stations execute operation OP511 to release resources.

[0111] As described above, if the result is negative, processor 23 executes operation OP506, whereby the source base station SgNB receives a prediction report containing the decision result of the user equipment (UE) (i.e., the prediction report indicates the first prediction base station). Next, processor 23 executes operation OP509, whereby the source base station SgNB transmits a handover cancellation request to the non-target base stations. Then, these candidate base stations execute operation OP511 to release resources.

[0112] In some embodiments, the processor 23 receives a handover success message from the target base station. Then, in response to receiving the handover success message from the target base station, the processor 23 transmits a state transition message to the target base station, wherein the state transition message includes a sequence number.

[0113] For easier understanding, please refer to Figure 6 The sequence diagram is shown in Figure 600. In this example, the source base station SgNB performs a conditional handover decision (CHOD) and transmits a handover request (HOR) to candidate base stations CgNB1, CgNB2, ..., CgNBn. Next, the candidate base stations CgNB1, CgNB2, ..., CgNBn perform call admission control (CAC) and send a handover request response (HOR_ACK) back to the source base station SgNB.

[0114] Next, the source base station SgNB transmits a Radio Resource Control Reconfiguration Message RRCR to the User Equipment (UE), and the source base station SgNB receives a Radio Resource Control Reconfiguration Complete Message RRCRC from the User Equipment (UE).

[0115] Next, the User Equipment (UE) performs Measurement Prediction (MP) and transmits a Predition Report (PR) to the source base station SgNB. Then, the source base station SgNB performs a Cancel Decision (CD) and transmits a Handover Cancel Request (HOC) to the non-target base stations CgNB2 and CgNBn. Finally, the non-target base stations CgNB2 and CgNBn perform Resource Release (RR).

[0116] In this example, the User Equipment (UE), the source base station SgNB, and the target base station CgNB1 perform a Conditional Handover Completion (CHOC). Next, the target base station CgNB1 transmits a Handover Success (HOS) to the source base station SgNB. The source base station SgNB then transmits a Sequence Number Transition (SST) to the target base station CgNB1. Finally, the source base station SgNB transmits a Handover Cancellation Request (HOC) to the non-target base stations CgNB2 and CgNBn. The non-target base stations CgNB2 and CgNBn perform a conventional Resource Release (RR).

[0117] As described above, in the mobile communication system 1 provided by the first embodiment of this disclosure, the source base station SgNB actively transmits a radio resource control reconfiguration message containing an indication message and a list of candidate base stations to the user equipment UE, so that the user equipment UE generates a corresponding prediction report based on the indication message. Then, the source base station SgNB can determine the non-target base stations among these candidate base stations based on the prediction report received from the user equipment UE. Accordingly, the source base station SgNB can transmit a handover cancellation request to the non-target base stations among these candidate base stations in advance, so that the non-target base stations release the reserved resources of the corresponding user equipment UE. Since the source base station SgNB provided in this disclosure can notify the non-target base stations to release reserved resources in advance, the resource utilization efficiency of the mobile communication system 1 can be improved.

[0118] Another embodiment of this invention is a transmission method, the flowchart of which is depicted in... Figure 7 The transmission method 700 is applicable to a source base station, such as the source base station SgNB described in the first embodiment. The source base station is communicatively connected to a user equipment and multiple candidate base stations, such as the user equipment UE and candidate base stations CgNB1, CgNB2, ..., CgNBn described in the first embodiment. The transmission method 700 transmits a handover cancellation request through steps S701 to S705.

[0119] In step S701, the source base station transmits a radio resource control reconfiguration message to the user equipment, wherein the radio resource control reconfiguration message includes an indication message and a candidate base station list, and the candidate base station list is used to indicate these candidate base stations. Next, in step S703, the source base station determines the non-target base stations among the candidate base stations based on a prediction report received from the user equipment, wherein the prediction report is generated based on the indication message.

[0120] Finally, in step S705, the source base station transmits a handover cancellation request to the non-target base station among these candidate base stations, so that the non-target base station releases the reserved resources of the corresponding user equipment.

[0121] In some implementations, the indication message includes a decision indication, and determining a non-target base station further includes the following steps: determining whether the indication message corresponds to a user equipment decision indication; and in response to the indication message corresponding to a user equipment decision indication, determining a non-target base station among these candidate base stations based on a first predicted base station indicated in the prediction report.

[0122] In some implementations, the prediction report includes predicted signal changes corresponding to each of the candidate base stations and a first predicted base station, and the determination of a non-target base station further includes the following steps: in response to an indication message corresponding to a user equipment decision indication, generating a prediction confidence value corresponding to the first predicted base station based on the predicted signal changes of each of the candidate base stations; and in response to the prediction confidence value being less than a threshold value, determining the first predicted base station as the non-target base station.

[0123] In some implementations, the prediction report includes predicted signal changes corresponding to each of the candidate base stations and a first predicted base station, and determining a non-target base station further includes the following steps: receiving base station status information from each of the candidate base stations; generating a prediction confidence value corresponding to the first predicted base station based on the predicted signal changes corresponding to each of the candidate base stations and the base station status information of each of the candidate base stations; and determining the first predicted base station as a non-target base station in response to the prediction confidence value being less than a threshold value.

[0124] In some implementations, the prediction report includes predicted signal changes corresponding to each of the candidate base stations, and determining a non-target base station further includes the steps of: selecting a second predicted base station from the candidate base stations based on the predicted signal changes corresponding to each of the candidate base stations; and designating the second predicted base station as the non-target base station.

[0125] In some embodiments, the transmission method 700 further includes the steps of: receiving base station status information from each of the candidate base stations; selecting a second predicted base station from the candidate base stations based on the predicted signal changes corresponding to each of the candidate base stations and the base station status information of each of the candidate base stations; and designating the second predicted base station as a non-target base station.

[0126] In some implementations, the base station status information includes load status and current location.

[0127] In some implementations, the prediction report is generated by the user equipment performing the following steps: measuring the user equipment's trajectory message; and generating the prediction report based on the historical signal sequence values ​​of each of the candidate base stations and the user equipment's trajectory message.

[0128] In some implementations, the trajectory message includes the user equipment's spatial location, direction of movement, and speed of movement.

[0129] In some embodiments, the transmission method 700 further includes the steps of: receiving a handover success message from the target base station; and in response to receiving the handover success message from the target base station, transmitting a state transition message to the target base station, wherein the state transition message includes a sequence number.

[0130] In some implementations, the candidate base stations in the candidate base station list are generated by the source base station performing conditional handover decision operations, and the transmission method 700 further includes the steps of: receiving handover request confirmation messages from each of the candidate base stations; and generating radio resource control reconfiguration messages based on the handover request confirmation messages.

[0131] In some implementations, the instruction message includes a decision instruction, a prediction parameter instruction, and an output type instruction.

[0132] In addition to the steps described above, the second embodiment can also perform all the operations and steps of the mobile communication system 1, the source base station SgNB, and the user equipment UE described in the first embodiment, and has the same functions and achieves the same technical effects. Those skilled in the art to which this disclosure pertains can directly understand how the second embodiment performs these operations and steps based on the first embodiment described above, has the same functions, and achieves the same technical effects, so it will not be described in detail here.

[0133] It should be noted that in the specification and claims of this case, certain terms (e.g., predictive base station) are preceded by "first" or "second," and these "first" and "second" are only used to distinguish different terms. For example, "first" and "second" in "first predictive base station" and "second predictive base station" are only used to indicate predictive base stations using different operating conditions.

[0134] In summary, the transmission technology (including at least a source base station and a method) disclosed herein involves the source base station actively transmitting a radio resource control reconfiguration message containing an indication message and a list of candidate base stations to the user equipment (UE), enabling the UE to generate a corresponding prediction report based on the indication message. Subsequently, the source base station can determine a non-target base station from among these candidate base stations based on the prediction report received from the UE. Accordingly, the source base station can transmit a handover cancellation request to the non-target base station among these candidate base stations in advance, causing the non-target base station to release reserved resources corresponding to the UE. Because the transmission technology disclosed herein can notify non-target base stations to release reserved resources in advance, the resource utilization efficiency of the mobile communication system can be improved.

[0135] The above embodiments are merely illustrative of some implementations of this case and to explain its technical features, and are not intended to limit the scope and extent of protection of this case. Any changes or equivalent arrangements that can be easily made by a person skilled in the art to which this case pertains are within the scope of this case, and the scope of protection of this case is determined by the claims.

Claims

1. A source base station, characterized in that, Include: A transceiver interface, providing communication connections to a user equipment and multiple candidate base stations; and A processor, electrically connected to the transceiver interface, is configured to perform the following operations: A radio resource control reconfiguration message is transmitted to the user equipment, wherein the radio resource control reconfiguration message includes an indication message and a candidate base station list, and the candidate base station list is used to indicate the plurality of candidate base stations; Based on a prediction report received from the user equipment, a non-target base station is determined from the plurality of candidate base stations, wherein the prediction report is generated based on the indication message; as well as A handover cancellation request is transmitted to the non-target base station among the plurality of candidate base stations, so that the non-target base station releases a reserved resource corresponding to the user equipment.

2. The source base station as described in claim 1, characterized in that, The indication message includes a decision indication, and determining the non-target base station also includes the following operations: Determine whether the instruction message corresponds to a user equipment decision instruction; and In response to the indication message corresponding to the user equipment decision indication, the non-target base station among the plurality of candidate base stations is determined based on a first predicted base station indicated in the prediction report.

3. The source base station as described in claim 2, characterized in that, The prediction report includes a predicted signal change corresponding to each of the plurality of candidate base stations and the first predicted base station, and the determination of the non-target base station also includes the following operations: In response to the indication message corresponding to the user equipment decision indication, a prediction confidence value corresponding to the first prediction base station is generated based on the prediction signal changes of each of the plurality of candidate base stations; as well as In response to the prediction confidence value being less than a threshold value, the first prediction base station is determined to be the non-target base station.

4. The source base station as described in claim 2, characterized in that, The prediction report includes a predicted signal change corresponding to each of the plurality of candidate base stations and the first predicted base station, and the determination of the non-target base station also includes the following operations: Receive a base station status information from each of the plurality of candidate base stations; Based on the predicted signal changes corresponding to each of the plurality of candidate base stations and the base station status information of each of the plurality of candidate base stations, a prediction confidence value corresponding to the first prediction base station is generated. as well as In response to the prediction confidence value being less than a threshold value, the first prediction base station is determined to be the non-target base station.

5. The source base station as described in claim 1, characterized in that, The prediction report includes a predicted signal change corresponding to each of the plurality of candidate base stations, and the determination of the non-target base station also includes the following operations: Based on the predicted signal changes corresponding to each of the plurality of candidate base stations, a second predicted base station is selected from the plurality of candidate base stations; and The second predicted base station is designated as the non-target base station.

6. The source base station as described in claim 5, characterized in that, The processor described therein performs the following operations: Receive a base station status information from each of the plurality of candidate base stations; Based on the predicted signal changes corresponding to each of the plurality of candidate base stations and the base station status information of each of the plurality of candidate base stations, the second predicted base station is selected from the plurality of candidate base stations; as well as The second predicted base station is designated as the non-target base station.

7. The source base station as described in claim 6, characterized in that, The base station status information includes a load status and a current location.

8. The source base station as described in claim 1, characterized in that, The prediction report is generated by the user equipment performing the following operations: Measuring a trajectory message of the user equipment; and The prediction report is generated based on a historical signal sequence value of each of the multiple candidate base stations and the trajectory message of the user equipment.

9. The source base station as described in claim 8, characterized in that, The trajectory message includes the user equipment's spatial location, direction of movement, and speed of movement.

10. The source base station as described in claim 1, characterized in that, The processor described therein performs the following operations: Receive a handover success message from a target base station; and In response to receiving the handover success message from the target base station, a state transition message is transmitted to the target base station, wherein the state transition message includes a sequence number.

11. The source base station as described in claim 1, characterized in that, The candidate base stations in the candidate base station list are generated by the source base station performing a conditional handover decision operation, and the processor further performs the following operations: Each of the plurality of candidate base stations receives a handover request confirmation message; and Based on the multiple handover request confirmation messages, the radio resource control reconfiguration message is generated.

12. The source base station as described in claim 1, characterized in that, The instruction message includes a decision instruction, a prediction parameter instruction, and an output type instruction.

13. A transmission method, characterized in that, Applicable to a source base station, wherein the source base station is communicatively connected to a user equipment and multiple candidate base stations, the transmission method includes the following steps: A radio resource control reconfiguration message is transmitted to the user equipment, wherein the radio resource control reconfiguration message includes an indication message and a candidate base station list, and the candidate base station list is used to indicate the plurality of candidate base stations; Based on a prediction report received from the user equipment, a non-target base station is determined from the plurality of candidate base stations, wherein the prediction report is generated based on the indication message; as well as A handover cancellation request is transmitted to the non-target base station among the plurality of candidate base stations, so that the non-target base station releases a reserved resource corresponding to the user equipment.

14. The transmission method as described in claim 13, characterized in that, The indication message includes a decision indication, and determining the non-target base station further includes the following steps: Determine whether the instruction message corresponds to a user equipment decision instruction; and In response to the indication message corresponding to the user equipment decision indication, the non-target base station among the plurality of candidate base stations is determined based on a first predicted base station indicated in the prediction report.

15. The transmission method as described in claim 14, characterized in that, The prediction report includes a predicted signal change corresponding to each of the plurality of candidate base stations and the first predicted base station, and determining the non-target base station further includes the following steps: In response to the indication message corresponding to the user equipment decision indication, a prediction confidence value corresponding to the first prediction base station is generated based on the prediction signal changes of each of the plurality of candidate base stations; as well as In response to the prediction confidence value being less than a threshold value, the first prediction base station is determined to be the non-target base station.

16. The transmission method as described in claim 14, characterized in that, The prediction report includes a predicted signal change corresponding to each of the plurality of candidate base stations and the first predicted base station, and determining the non-target base station further includes the following steps: Receive a base station status information from each of the plurality of candidate base stations; Based on the predicted signal changes corresponding to each of the plurality of candidate base stations and the base station status information of each of the plurality of candidate base stations, a prediction confidence value corresponding to the first prediction base station is generated. as well as In response to the prediction confidence value being less than a threshold value, the first prediction base station is determined to be the non-target base station.

17. The transmission method as described in claim 13, characterized in that, The prediction report includes a predicted signal change corresponding to each of the plurality of candidate base stations, and determining the non-target base station further includes the following steps: Based on the predicted signal changes corresponding to each of the plurality of candidate base stations, a second predicted base station is selected from the plurality of candidate base stations; and The second predicted base station is designated as the non-target base station.

18. The transmission method as described in claim 17, characterized in that, The transmission method further includes the following steps: Receive a base station status information from each of the plurality of candidate base stations; Based on the predicted signal changes corresponding to each of the plurality of candidate base stations and the base station status information of each of the plurality of candidate base stations, the second predicted base station is selected from the plurality of candidate base stations; as well as The second predicted base station is designated as the non-target base station.

19. The transmission method as described in claim 13, characterized in that, The prediction report is generated by the user equipment performing the following steps: Measuring a trajectory message of the user equipment; and The prediction report is generated based on a historical signal sequence value of each of the multiple candidate base stations and the trajectory message of the user equipment.

20. The transmission method as described in claim 19, characterized in that, The trajectory message includes the user equipment's spatial location, direction of movement, and speed of movement.

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