CN109121168B - A handover method, base station and computer storage medium - Google Patents

Abstract

The embodiment of the present invention discloses a handover method, a base station and a computer storage medium. The method includes: the source base station receives the handover request confirmation information of the target base station; the source base station sends a first data packet to the target base station; the first data packet is stored by the source base station and has a predetermined relationship with the first data packet. Packets with set isolation.

Description

A handover method, base station and computer storage medium

technical field

The present invention relates to wireless communication technology, in particular to a handover method, a base station and a computer storage medium.

Background technique

The International Telecommunication Union (ITU, International Telecommunication Union) defines three major application scenarios of 5G and proposes more challenging key index capabilities than 4G. On the other hand, in order to achieve the continuity of the service during the internal handover of NR, that is, to achieve the lossless handover target of 0ms, during the internal handover process of the wireless access (NR, New Radio), the terminal should always keep in touch with the source base station (gNB). connect. Under such a consensus, the source gNB should determine which Packet Data Convergence Protocol (PDCP) Service Data Unit (SDU, Service Data Unit) should be sent to the target gNB through the Xn interface in an appropriate allocation manner during the handover process . However, due to the uncertainty of the handover completion time, the source gNB cannot predict which PDCP protocol data unit (PDU) PDU/SDU is the last one it is responsible for sending to the terminal, and if the source gNB does not send the subsequent PDCP PDU to the target gNB in time /SDU, the service in handover will not be able to achieve seamless continuity, that is, it cannot meet the requirement of 0ms lossless handover.

SUMMARY OF THE INVENTION

To solve the existing technical problems, embodiments of the present invention provide a handover method, a base station, and a computer storage medium.

In order to achieve the above-mentioned purpose, the technical scheme of the embodiment of the present invention is realized as follows:

An embodiment of the present invention provides a handover method, which is applied to a source base station; the method includes:

The source base station receives the handover request confirmation information of the target base station;

The source base station sends a first data packet to the target base station; the first data packet is a data packet with a preset isolation degree from the first data packet stored by the source base station.

In the above solution, the method further includes: after receiving the serial number (SN) request information of the target base station, sending an SN to the target base station based on the SN request information; the SN is the first SN not used by the terminal Confirm the SN of the received data packet, or be the SN of the first data packet that the source base station expects the target base station to send to the terminal.

In the above solution, before the SN request information of the target base station is received, the method further includes:

The source base station sends a second data packet to the terminal; the second data packet is other data packets except the first data packet stored by the source base station;

When the source base station receives the first acknowledgment information of the terminal, it sends an SN status report corresponding to the first acknowledgment information to the target base station;

Wherein, the first confirmation information indicates that the terminal has received the second data packet.

In the above solution, the method further includes: sending, by the source base station, an unsent data packet to the terminal.

In the above scheme, the method also includes:

Analyze the delay characteristics of the air interface, and perform isolation between the data packets sent by the source base station to the terminal and the data packets sent by the source base station to the target base station based on the delay characteristics and preset parameters. Adjustment;

The preset parameter includes at least one of the following parameters: a communication channel parameter between the source base station and the terminal, and a service requirement parameter for a data transmission rate.

In the above solution, the method further includes: after receiving the SN request information of the target base station, or after sending the SN to the target base station, releasing the connection with the terminal.

In the above solution, the first data packet is the first data packet among the data packets stored by the source base station and to be sent to the terminal.

In the above solution, the preset isolation degree represents a preset relative distance between the first data packet sent by the source base station to the terminal and the first data packet sent by the source base station to the target base station.

The embodiment of the present invention also provides a handover method, which is applied to a target base station; the method includes:

The target base station sends SN request information to the source base station;

Receive the SN of the source base station; the SN is the SN of the first data packet that is not acknowledged by the terminal, or the SN of the first data packet that the source base station expects the target base station to send to the terminal.

In the above solution, the method further includes: the target base station sends a third data packet to the terminal based on the SN, where the third data packet is the first data packet that is not acknowledged by the terminal to receive, or is the first data packet received by the terminal. The source base station expects the first data packet sent by the target base station to the terminal.

In the above solution, the method further includes: sending, by the target base station, an unsent data packet to the terminal.

An embodiment of the present invention further provides a base station, where the base station includes: a first receiving unit and a first sending unit; wherein,

the first receiving unit, configured to receive the handover request confirmation information of the target base station;

The first sending unit is configured to send a first data packet to the target base station; the first data packet is a stored data packet with a preset isolation degree from the first data packet.

In the above solution, the first receiving unit is further configured to receive the SN request information of the target base station;

The first sending unit is further configured to send the SN to the target base station based on the SN request information; the SN is the SN of the first data packet that is not confirmed to be received by the terminal, or is the SN that the target base station expects to send to the target base station. SN of the first data packet sent by the terminal.

In the above solution, the first sending unit is further configured to send a second data packet to the terminal before the first receiving unit receives the SN request information of the target base station; the second data packet is a storage other data packets except the first data packet;

The first receiving unit is further configured to receive first confirmation information of the terminal; the first confirmation information indicates that the terminal has received the second data packet;

The first sending unit is further configured to send an SN status report corresponding to the first confirmation information to the target base station.

In the above solution, the first sending unit is further configured to send unsent data packets to the terminal.

In the above solution, the base station further includes an analysis and processing unit for analyzing the delay characteristics of the air interface, and based on the delay characteristics and preset parameters, the data packets sent to the terminal and the data sent to the target base station are compared. The isolation degree between packets is adjusted; the preset parameter includes at least one of the following parameters: a communication channel parameter with the terminal, and a service requirement parameter for a data transmission rate.

In the above solution, the base station further includes a release unit configured to release the connection with the terminal after receiving the SN request information of the target base station or after sending the SN to the target base station.

An embodiment of the present invention further provides a base station, the base station includes: a second sending unit and a second receiving unit; wherein,

the second sending unit, configured to send the SN request information to the source base station;

The second receiving unit is used to receive the SN of the source base station; the SN is the SN of the first data packet that is not confirmed by the terminal to receive, or the SN that the source base station expects the target base station to send to the terminal. SN of the first packet.

In the above solution, the second sending unit is further configured to send a third data packet to the terminal based on the SN, where the third data packet is the first data packet that has not been confirmed to be received by the terminal, or is the The source base station expects the first data packet sent by the target base station to the terminal.

In the above solution, the second sending unit is further configured to send unsent data packets to the terminal.

The embodiment of the present invention also provides a computer-readable storage medium, which stores computer instructions, characterized in that, when the instructions are executed by a processor, the steps of the handover method applied to the source base station according to the embodiment of the present invention are implemented ;

Or, when the instruction is executed by the processor, the steps of the handover method applied to the target base station according to the embodiment of the present invention are implemented.

An embodiment of the present invention further provides a base station, including a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, when the processor executes the program, the embodiment of the present invention is implemented Steps of the described handover method applied to the source base station;

Alternatively, when the processor executes the program, the steps of the handover method applied to the target base station according to the embodiment of the present invention are implemented.

In the handover method, base station, and computer storage medium provided by the embodiments of the present invention, on the one hand, the source base station receives the handover request confirmation information of the target base station; the source base station sends a first data packet to the target base station; the first data packet is all The source base station stores a data packet with a preset isolation degree from the first data packet; on the other hand, the target base station sends SN request information to the source base station; receives the SN of the source base station; the SN is the first non-terminal Confirm the SN of the received data packet, or be the SN of the first data packet sent by the target base station to the terminal. By adopting the technical solutions of the embodiments of the present invention, the target base station can request the SN from the source base station to make the target The base station knows which data packet it should start sending to the terminal, and realizes 0ms lossless handover during the handover process of the terminal from the source base station to the target base station, reducing the data transmission volume of the air interface.

Description of drawings

FIG. 1 is a schematic flowchart of a handover method according to Embodiment 1 of the present invention;

2 is a schematic flowchart of a handover method according to Embodiment 2 of the present invention;

3 is a schematic flowchart of a handover method according to Embodiment 3 of the present invention;

4a and 4b are schematic diagrams of an application of the handover method according to an embodiment of the present invention;

5a and 5b are schematic diagrams of another application of the handover method according to the embodiment of the present invention;

6 is a schematic diagram of a first composition structure of a base station according to an embodiment of the present invention;

7 is a schematic diagram of a second composition structure of a base station according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of a third composition structure of a base station according to an embodiment of the present invention;

9 is a schematic diagram of a fourth composition structure of a base station according to an embodiment of the present invention;

FIG. 10 is a schematic structural diagram of a hardware composition of a base station according to an embodiment of the present invention.

Detailed ways

Before describing the embodiments of the present invention in detail, handover between base stations is first described in detail.

In the existing Long Term Evolution (LTE, Long Term Evolution) protocol, when the terminal needs to be handed over from the source eNB to the target eNB, the source eNB sends the terminal RRC Reconfigure signaling to instruct the terminal to initiate the handover process to the target eNB, and then stops to send downlink data to the terminal. At this time, the source eNB sends some information to the target eNB through the X2 interface, for example:

The SN of the PDCP SDU and the corresponding first PDCP SDU existing in the buffer of the source eNB but not yet sent;

The source eNB did not receive the confirmation of the correct reception of the feedback from the UE in time, but the UE later confirmed the correctly received SN status report of the PDCP.

In 5G, however, the source eNB did not receive timely confirmation from the user equipment (UE) that the feedback was correctly received, but the UE later confirmed the correctly received PDCP SN status report.

The PDCP layer of the source gNB and the PDCP layer of the target gNB are two independent entities. During the handover process, the source gNB forwards to the target gNB the PDCP PDU with SN assigned and the PDCP SDU without SN assigned to the UE. In order for the target gNB to know the sequence and interval relationship between the data packets it receives from the source gNB and the last PDCP PDU downlink from the source gNB to the UE, the source gNB also transmits the corresponding SN number to the target gNB . Subsequent PDCP DUs and corresponding SN numbers from the target gNB downlink to the UE are consecutive, and are implicitly determined by the sequence relationship between them or with the first PDCP PDU forwarded to the target gNB (the GTP-U protocol SN numbers guarantee that they can be reordered at the target gNB).

In order to achieve 0ms handover, the UE should maintain a consensus on the connection with the source gNB during the handover process. Under such a consensus, which PDCP SDUs should be sent to the target gNB through the Xn interface during the handover process should be determined in an appropriate allocation manner to achieve the following two goals:

During the handover process, it is ensured that downlink data can be continuously sent to the terminal (that is, the service is not interrupted);

After the handover process is completed, it is ensured that the target gNB can send the subsequent PDCP SDU seamlessly connected with the last PDCP PDU/SDU from the source gNB downlink to the terminal to the UE in time (seamless service connection between dual gNBs).

During the handover process, due to the uncertainty of the handover completion time, the source gNB cannot predict which PDCP PDU/SDU is the last one that it is responsible for downlinking to the terminal. The existing LTE handover scheme cannot provide such a service, and if the source gNB does not send the seamless subsequent PDCP PDU/SDU to the target gNB in time, the service in the handover will not be able to achieve seamless continuity.

Based on the above description, the following embodiments of the present invention are proposed.

The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

Example 1

The embodiment of the present invention provides a handover method, which is applied in a source base station. FIG. 1 is a schematic flowchart of a handover method according to Embodiment 1 of the present invention; as shown in FIG. 1 , the method includes:

Step 101: The source base station receives the handover request confirmation information of the target base station.

Step 102: The source base station sends a first data packet to the target base station; the first data packet is a data packet stored by the source base station with a preset isolation degree from the first data packet.

In this embodiment, as an implementation manner, the first data packet is the first data packet in the data packets to be sent to the terminal stored by the source base station. Of course, in other implementation manners, the first data packet may also indicate that the second data packet, the third data packet, or the Nth (N is a positive integer) data packet stored by the source base station has a preset value. Isolation data packet; the second data packet, the third data packet or the Nth (N is a positive integer) data packet is specifically in the data packet stored by the source base station and to be sent to the terminal The second, third, or Nth (N is a positive integer) packet of .

In this embodiment, after the source base station receives the handover request confirmation information from the target base station, or after receiving the handover request confirmation information from the target base station and sends the RRC reconfiguration signaling to the terminal, the source base station stores the The first data packet with the preset isolation degree is forwarded to the target base station; it may carry the SN of the first data packet. In the above process, the source base station continues to send downlink data to the terminal through the air interface, and the terminal initiates a synchronization and random access process to the target base station. The preset isolation degree represents a preset relative distance between the first data packet sent by the source base station to the terminal and the first data packet sent by the source base station to the target base station. As an embodiment, if the number of data packets is used as a unit, the preset isolation degree can represent the first data packet sent by the source base station to the terminal and the first data packet sent by the source base station to the target base station. The preset number of packets between the first packets.

In this embodiment, the terminal applied to the handover method of the embodiment of the present invention specifically has the capability of sending and receiving dual radio frequency links, or can switch between the source base station and the target base station in a time division multiplexing (TDM) manner, To ensure that there can be two links for wireless communication at the same time.

As an embodiment, the method further includes: after receiving the serial number (SN) request information of the target base station, sending an SN to the target base station based on the SN request information; the SN is the first unresolved SN. The terminal confirms the SN of the received data packet, or is the SN of the first data packet that the source base station expects the target base station to send to the terminal.

In this embodiment, after the terminal sends the RRC connection reconfiguration signaling to the target base station, and the target base station is ready to start sending downlink data to the terminal, the target base station sends SN request information to the source base station to request the current PDCP SDU The source base station sends the corresponding SN to the target base station based on the received SN request information, so that the target base station sends the possible subsequent data packets to the terminal based on the received SN.

As an implementation manner, before the receiving the SN request information of the target base station, the method further includes: the source base station sends a second data packet to the terminal; the second data packet is the source other data packets except the first data packet stored by the base station; when the source base station receives the first confirmation information of the terminal, it sends an SN status report corresponding to the first confirmation information to the target base station , so that the target base station deletes the data packet corresponding to the SN status report; wherein, the first confirmation information indicates that the terminal has received the second data packet.

In this embodiment, before the source base station receives the SN request information from the target base station, or after the source base station forwards data to the target base station and transfers the SN, the source base station continues to send messages to the terminal except for the first other data packets than data packets; after receiving the first acknowledgment information from the terminal, that is, when the terminal informs the source base station that the corresponding data packet has been received, the source base station sends an SN status report to the target base station to causing the target base station to delete the corresponding redundant data packets according to the SN status report.

As an implementation manner, the method further includes: the source base station sends the unsent data packets to the terminal, that is, the source base station does not interrupt sending the data packets to the terminal. As another implementation manner, the source base station and the target base station may simultaneously send unsent data packets to the terminal.

Specifically, in an implementation manner, the source base station sends unsent data packets to the terminal without interruption. As another implementation manner, the source base station and the target base station simultaneously send unsent data packets to the terminal, and the terminal enters a state of simultaneous dual transmission and reception, and can detect duplicate data packets according to the SN and discard redundant data packets. data pack. In this embodiment, the source base station and the target base station send unsent data packets to the terminal at the same time, which can be applied in the information exchange process, after the source base station forwards data to the target base station and transfers the SN, and the target base station instructs the user Before the device releases the resources of the source base station, it can be applied after the completion of step 8 and before step 14 in FIG. 3 .

As an implementation manner, the method further includes: analyzing the time delay characteristic of the air interface, and based on the time delay characteristic and preset parameters, compare the data packets sent by the source base station to the terminal and the data packets sent by the source base station to the terminal. The isolation between the data packets sent by the target base station is adjusted; the preset parameter includes at least one of the following parameters: a communication channel parameter between the source base station and the terminal, a service requirement parameter for a data transmission rate .

In this embodiment, the source base station continuously analyzes the time delay characteristics of the air interface (for example, the Xn interface) in the time domain, and refers to other information (that is, the preset parameters) to send the source base station to the terminal. The isolation degree between the data packets sent by the source base station to the target base station is adjusted, thereby reducing the waste of transmission resources on the air interface.

As an embodiment, the method further includes: after receiving the SN request information of the target base station, or after sending the SN to the target base station, releasing the connection with the terminal.

In this embodiment, after the source base station receives the SN request information of the target base station, or after sending the SN to the target base station, the source base station can release the resources with the terminal, that is, release the wireless connection with the terminal . In another embodiment, the terminal may also actively release the wireless connection with the source base station based on the instruction of the target base station. As another implementation manner, after the terminal sends the RRC connection reconfiguration completion signaling to the target base station, the terminal may also actively release resources with the source base station, that is, release the wireless connection with the source base station.

By adopting the technical solutions of the embodiments of the present invention, by reasonably setting the isolation degree between the data packets sent by the source base station to the terminal and the data packets sent by the source base station to the target base station, on the one hand, the terminal is sent from the source base station to the target base station. During the handover process, a lossless handover of 0ms is realized, and on the other hand, the data transmission amount of the air interface is reduced.

Embodiment 2

The embodiment of the present invention also provides a handover method, which is applied to a target base station. FIG. 2 is a schematic flowchart of a handover method according to Embodiment 2 of the present invention; as shown in FIG. 2 , the method includes:

Step 201: The target base station sends SN request information to the source base station.

Step 202: Receive the SN of the source base station; the SN is the SN of the first data packet not confirmed by the terminal to receive, or the SN of the first data packet that the source base station expects the target base station to send to the terminal. SN.

In this embodiment, after the terminal sends the RRC connection reconfiguration signaling to the target base station, and the target base station is ready to start sending downlink data to the terminal, the target base station sends SN request information to the source base station to request the current PDCP SDU The source base station sends the corresponding SN to the target base station based on the received SN request information, so that the target base station sends the possible subsequent data packets to the terminal based on the received SN.

In this embodiment, the terminal applied to the handover method of the embodiment of the present invention specifically has the capability of sending and receiving dual radio frequency links, or can switch between the source base station and the target base station by means of TDM, so as to ensure that there can be two wireless communication over the links simultaneously.

As an implementation manner, the method further includes: the target base station sends a third data packet to the terminal based on the SN, where the third data packet is the first data packet that is not acknowledged by the terminal to receive, or It is the first data packet that the source base station expects the target base station to send to the terminal.

In this embodiment, the target base station sends a data packet corresponding to the SN based on the SN sent by the source base station; the data packet may specifically be the first data packet that is not confirmed to be received by the terminal, or the The source base station expects the first data packet sent by the target base station to the terminal.

As an implementation manner, the method further includes: sending, by the target base station, an unsent data packet to the terminal. As another implementation manner, the target base station and the source base station may simultaneously send unsent data packets to the terminal.

Specifically, in the latter embodiment, the source base station and the target base station send unsent data packets to the terminal at the same time; the terminal enters a state of simultaneous dual transmission and reception, and can detect duplicate data packets according to the SN and discard redundant packets. In this embodiment, the source base station and the target base station send unsent data packets to the terminal at the same time, which can be applied in the information exchange process, after the source base station forwards data to the target base station and transfers the SN, and the target base station instructs the user Before the device releases the resources of the source base station, it can be applied after the completion of step 8 and before step 14 in FIG. 3 .

By adopting the technical solutions of the embodiments of the present invention, the target base station requests the SN from the source base station, so that the target base station knows which data packet it should start sending to the terminal, and a 0ms lossless handover is realized during the handover process of the terminal from the source base station to the target base station. To avoid the problem of sending too many data packets to the terminal when sending data packets too early, or to avoid sending data packets too late and causing the terminal to send an ACK confirmation message to the target base station, it needs to fall back to the currently needed data packets, and then press Sequential transmission reduces the amount of data transmitted over the air interface.

Embodiment 3

The embodiment of the present invention also provides a handover method. FIG. 3 is a schematic flowchart of a handover method according to Embodiment 3 of the present invention; as shown in FIG. 3 , in this embodiment, a specific processing flow is used to describe the handover method in this embodiment of the present invention in detail. ) to switch to the target base station (Target gNB) as an example to illustrate, the hardware entities required in the information exchange process also include a Serving Gateway (Serving Gateway) and a Mobility Management Entity (MME, Mobility Management Entity). The method includes:

Step 0: The source base station exchanges data with the serving gateway, and provides area restriction (Area RestrictionProvided) information.

Step 1: The source base station sends a measurement control request (Measurement Control) to the user equipment. After step 1 is completed, data packets are transmitted between the user equipment and the source base station, and between the source base station and the serving gateway; the source base station allocates uplink resources (UL allocation) to the user equipment. ).

Step 2: The user equipment sends measurement reports (Measurement Reports) to the source base station.

Step 3: The source base station makes a handover decision (HO decision, namely HandOver decision), that is, the user equipment is to be handed over from the source base station to the target base station.

Step 4: The source base station sends a handover request (Handover Request) to the target base station.

Step 5: the target base station admission control (Admission Control), that is, the target base station allows the user equipment to be handed over to the target base station.

Step 6: The target base station sends a handover request acknowledgement (Handover Request Ack) to the source base station. After the execution of step 6 is completed, the source base station allocates downlink resources (DL allocation) to the user equipment.

Step 7: The source base station completes the RRC connection reconfiguration (RRC Conn.Reconf.incl.mobilityControlinformation) with the user equipment (including mobility control information).

Step 8: The source base station forwards data to the target base station and transfers SN (Data Forwarding+SN of FP). After step 8 is completed, data packets are transmitted between the user equipment and the source base station; and the target base station buffers data packets (Buffer packets from Source gNB) from the source base station.

Step 9: The user equipment is synchronized with the target base station (Synchronisation).

Step 10: The target base station allocates uplink resources and time domain synchronization information (UL allocation+TA for UE) to the user equipment.

Step 11: The user equipment completes the RRC connection reconfiguration with the target base station (RRCConn.Reconf.Complete).

Step 12: The target base station sends an SN request (SN enquiry) to the source base station.

Step 13: The source base station sends an SN status report (SN status report) to the target base station, and the SN status report includes the SN. The SN may be the SN of the first data packet not acknowledged by the terminal, or the The SN of the first data packet sent by the target base station to the terminal.

Step 14: The target base station instructs the user equipment to release the source base station resource (Release source cell). After step 14 is performed, the terminal attaches from the source base station (Detach from old cell).

Step 15: The target base station sends a path switch request (Path Switch Request) to the MME.

Step 16: The MME sends a Modify Bearer Request to the serving gateway.

Step 17: The serving gateway switches the downlink path (Switch DL path).

Step 18: The serving gateway sends a Modify Bearer Response to the MME.

Step 19: The MME sends a Modify Bearer Response Ack to the target base station.

Step 20: The target base station instructs the source base station to release the user equipment connection (UE Context Release).

Step 21: The source base station releases resources (ReleaseResources) with the user equipment based on the instruction of the target base station.

The handover method according to the embodiment of the present invention will be described in detail below with reference to specific application scenarios.

Application Scenario One

4a and 4b are schematic diagrams of an application of the handover method according to the embodiment of the present invention; this application scenario is applicable to the scenario where the Xn interface between the source gNB and the target gNB is first established, which can be understood as zero SN isolation. This embodiment means that the source gNB forwards all the buffered data and the corresponding SN of the first data packet to the target gNB intact. In order to prevent the gNB's cache from being filled up, the source gNB informs the target gNB of the SN of the data packet that has been successfully delivered to the terminal; the target gNB correspondingly deletes the corresponding data in the cache according to this information. As shown in Figure 4a, the source gNB sends all the data in the cache (the data packets with SN numbers from 1 to 100 in the figure (there may be some data packets such as the 89th to 100th data packets that have not been assigned SN numbers)) and the corresponding SN numbers to the The target gNB sends. When the terminal replies to the source gNB to confirm the reception of a certain data packet, the source gNB sends the reply confirmation information to the target gNB in the form of "SN status report", so that the target gNB deletes the corresponding data packet in its cache. Before and after the terminal handover is completed, as shown in Fig. 4b, the source gNB continues to forward the data packets delivered by the user plane gateway to the target gNB (SN>100 in this example). After the target gNB sends an SN request (SN enquiry) message to the source gNB, the source gNB informs the target gNB through the Xn interface of the SN number of the initial PDCP SDU that needs to be sent to the UE (SN=72 in this example, that is, the SN with SN of 72 is sent to the UE. to the target gNB). After the path switching is completed, the user plane gateway issues a terminator (LP) to the source gNB, and the source gNB forwards the terminator to the target gNB to inform the target gNB that the data forwarding task is completed.

Application Scenario 2

5a and 5b are schematic diagrams of another application of the handover method according to the embodiment of the present invention; different from the first application scenario, this application scenario is applicable to the SN number of the data packet sent to the terminal after a period of time and the data forwarded to the target gNB The interval between the SN numbers of the packets is more appropriately adjusted by statistically analyzing the delay of the Xn interface in the time domain. In this application scenario, it is assumed that the statistical analysis shows that the data packets from SN=1 to SN=68 are directly transmitted to the terminal through the air interface between the source gNB and the terminal, and the terminal has not completed the handover operation. An isolation line is drawn between PDCP PDUs with SN=68 and SN=69, that is, in this example, data packets from SN=1 to SN=68 are directly transmitted to the terminal through the air interface (that is, the source gNB does not need to assign SN=1 to SN=68 The data packets of SN=69 to SN=100 are forwarded to the target gNB through the Xn interface, as shown in Figure 5a. Before and after the terminal handover is completed, as shown in Figure 5b, the source gNB continues to forward the data packets sent by the user plane gateway to the target gNB (SN>100 in this example). After the target gNB sends an SN request (SN enquiry) message to the source gNB, the source gNB informs the target gNB through the Xn interface of the SN number of the initial PDCP SDU that needs to be sent to the UE (SN=72 in this example, that is, the SN with SN of 72 is sent to the UE. to the target gNB). After the path switching is completed, the user plane gateway issues a terminator (LP) to the source gNB, and the source gNB forwards the terminator to the target gNB to inform the target gNB that the data forwarding task is completed.

Embodiment 4

An embodiment of the present invention further provides a base station, where the base station is a source base station. FIG. 6 is a schematic diagram of a first composition structure of a base station according to an embodiment of the present invention; as shown in FIG. 6 , the base station includes: a first receiving unit 41 and a first sending unit 42; wherein,

The first receiving unit 41 is configured to receive the handover request confirmation information of the target base station;

The first sending unit 42 is configured to send a first data packet to the target base station; the first data packet is a stored data packet with a preset isolation degree from the first data packet.

In this embodiment, the first data packet is the first data packet in the stored data packets to be sent to the terminal.

In this embodiment, the preset isolation degree represents a preset relative distance between the first data packet sent by the source base station to the terminal and the first data packet sent by the source base station to the target base station.

As an implementation manner, the first receiving unit 41 is further configured to receive the SN request information of the target base station;

The first sending unit 42 is further configured to send the SN to the target base station based on the SN request information; the SN is the SN of the first data packet that is not confirmed to be received by the terminal, or the target base station expects the SN SN of the first data packet sent to the terminal.

As an implementation manner, the first sending unit 42 is further configured to send a second data packet to the terminal before the first receiving unit 41 receives the SN request information of the target base station; The data packets are other data packets stored except the first data packet;

The first receiving unit 41 is further configured to receive the first confirmation information of the terminal; the first confirmation information indicates that the terminal has received the second data packet;

The first sending unit 42 is further configured to send the SN status report corresponding to the first confirmation information to the target base station, so that the target base station deletes the data packet corresponding to the SN status report.

As an implementation manner, the first sending unit 42 is further configured to send unsent data packets to the terminal.

FIG. 7 is a schematic diagram of a second composition structure of a base station according to an embodiment of the present invention; as shown in FIG. 7 , the base station further includes an analysis and processing unit 43 for analyzing the time delay characteristic of the air interface, based on the time delay characteristic and the pre- Set parameters to adjust the isolation between the data packets sent to the terminal and the data packets sent to the target base station; the preset parameters include at least one of the following parameters: communication with the terminal Channel parameters, service requirements for data transmission rate parameters.

FIG. 8 is a schematic diagram of a third composition structure of a base station according to an embodiment of the present invention; as shown in FIG. 8 , the base station further includes a release unit 44 for receiving the SN request information of the target base station, or to the After the target base station sends the SN, it releases the connection with the terminal.

Those skilled in the art should understand that the functions of each processing unit in the base station in the embodiment of the present invention can be understood by referring to the relevant description of the foregoing handover method. It can be realized by the analog circuit of the above-mentioned functions, and it can also be realized by running the software for executing the functions described in the embodiments of the present invention on the intelligent terminal.

In this embodiment of the present invention, the analysis and processing unit 43 and the release unit 44 in the base station may be composed of a central processing unit (CPU, Central Processing Unit) and a digital signal processor (DSP, Digital) in the base station in practical applications. Signal Processor), Microcontroller Unit (MCU, Microcontroller Unit) or Programmable Gate Array (FPGA, Field-Programmable Gate Array); the first receiving unit 41 and the first sending unit 42 in the base station, in practical applications It can be implemented through communication modules (including: basic communication suite, operating system, communication modules, standardized interfaces and protocols, etc.) and transceiver antennas.

Embodiment 5

An embodiment of the present invention further provides a base station, and the base station can be used as a target base station. FIG. 9 is a schematic diagram of a fourth composition structure of a base station according to an embodiment of the present invention; as shown in FIG. 9 , the base station includes: a second sending unit 51 and a second receiving unit 52; wherein,

The second sending unit 51 is configured to send SN request information to the source base station;

The second receiving unit 52 is configured to receive the SN of the source base station; the SN is the SN of the first data packet that is not acknowledged by the terminal to receive, or the source base station expects the target base station to send to the terminal SN of the first packet.

As an implementation manner, the second sending unit 51 is further configured to send a third data packet to the terminal based on the SN, where the third data packet is the first data packet that has not been confirmed to be received by the terminal, Or it is the first data packet that the source base station expects the target base station to send to the terminal.

As an implementation manner, the second sending unit 51 is further configured to send unsent data packets to the terminal.

Those skilled in the art should understand that the functions of each processing unit in the base station in the embodiment of the present invention can be understood by referring to the relevant description of the foregoing handover method. It can be realized by the analog circuit of the above-mentioned functions, and it can also be realized by running the software for executing the functions described in the embodiments of the present invention on the intelligent terminal.

In this embodiment of the present invention, the second sending unit 51 and the second receiving unit 52 in the base station can pass through a communication module (including a basic communication suite, an operating system, a communication module, standardized interfaces and protocols, etc.) in practical applications. ) and the transceiver antenna implementation.

Embodiment 6

The embodiment of the present invention also provides a base station. FIG. 10 is a schematic diagram of a hardware structure of a base station according to an embodiment of the present invention; as shown in FIG. 10 , the apparatus includes a processor 61, a memory 62, and at least one external communication interface 63; The external communication interfaces 63 are all connected through the bus 64 . Specifically, in this embodiment, the memory 62 stores a computer program that can run on the processor 61; when the base station is used as the source base station, the processor 61 executes the program to achieve: receiving the target base station The handover request confirmation information; send the first data packet to the target base station; the first data packet is the data packet stored in the memory 62 and has a preset isolation degree from the first data packet.

As an implementation manner, when the processor 61 executes the program, it realizes: after receiving the serial number SN request information of the target base station, send the SN to the target base station based on the SN request information; the SN is the first The SN of the data packet that has not been acknowledged by the terminal, or the SN of the first data packet that the source base station expects the target base station to send to the terminal.

As an implementation manner, when the processor 61 executes the program, it realizes: before receiving the SN request information of the target base station, send a second data packet to the terminal; the second data packet is the memory 62 other data packets other than the first data packet stored; when receiving the first acknowledgment information of the terminal, send an SN status report corresponding to the first acknowledgment information to the target base station; wherein, the The first confirmation information indicates that the terminal has received the second data packet.

As an implementation manner, when the processor 61 executes the program, it implements: sending an unsent data packet to the terminal.

As an embodiment, when the processor 61 executes the program, it realizes: analyzes the delay characteristic of the air interface, and compares the data packet sent to the terminal with the target base station based on the delay characteristic and preset parameters. The isolation between the sent data packets is adjusted; the preset parameter includes at least one of the following parameters: a communication channel parameter with the terminal, and a service requirement parameter for a data transmission rate.

As an implementation manner, when the processor 61 executes the program, it realizes: after receiving the SN request information of the target base station, or after sending the SN to the target base station, the connection with the terminal is released.

When the base station is used as the target base station, when the processor 61 executes the program, it realizes: sending SN request information to the source base station; receiving the SN of the source base station; the SN is the first data packet that is not confirmed by the terminal to receive it SN, or the SN of the first data packet that the source base station expects the target base station to send to the terminal.

As an implementation manner, when the processor 61 executes the program, it realizes: sending a third data packet to the terminal based on the SN, where the third data packet is the first data packet that has not been confirmed to be received by the terminal , or the first data packet that the source base station expects the target base station to send to the terminal.

As an implementation manner, when the processor 61 executes the program, it implements: sending an unsent data packet to the terminal.

In this embodiment, the memory 62 may be implemented by any type of volatile or non-volatile storage device, or a combination thereof. Among them, the non-volatile memory may be a read-only memory (ROM, Read Only Memory), a programmable read-only memory (PROM, Programmable Read-Only Memory), an erasable programmable read-only memory (EPROM, Erasable Programmable Read-only memory) Only Memory), Electrically Erasable Programmable Read-Only Memory (EEPROM, Electrically Erasable Programmable Read-Only Memory), Magnetic Random Access Memory (FRAM, Ferromagnetic Random Access Memory), Flash Memory (Flash Memory), Magnetic Surface Memory , CD-ROM, or Compact Disc Read-Only Memory (CD-ROM, Compact Disc Read-Only Memory); the magnetic surface memory can be a magnetic disk memory or a tape memory. The volatile memory may be Random Access Memory (RAM), which is used as an external cache memory. By way of example and not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Synchronous Static Random Access Memory (SSRAM), Dynamic Random Access Memory Memory (DRAM, Dynamic Random Access Memory), Synchronous Dynamic Random Access Memory (SDRAM, SynchronousDynamic Random Access Memory), Double Data Rate Synchronous Dynamic Random Access Memory (DDRSDRAM, Double Data Rate Synchronous Dynamic Random Access Memory), Enhanced Synchronous Dynamic Random Access Memory (ESDRAM, Enhanced Synchronous Dynamic Random Access Memory), Synchronous Link Dynamic Random Access Memory (SLDRAM, SyncLink Dynamic Random Access Memory), Direct Memory Bus Random Access Memory (DRRAM, Direct Rambus Random Access Memory) . The memory 804 described in the embodiments of the present invention is intended to include, but not be limited to, these and any other suitable types of memory.

In this embodiment, the processor 61 may be an integrated circuit chip with signal processing capability. In the implementation process, each step of the above-mentioned method can be completed by a hardware integrated logic circuit in the processor 61 or an instruction in the form of software. The above-mentioned processor 61 may be a general-purpose processor, a DSP, or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and the like. The processor 61 may implement or execute the methods, steps, and logical block diagrams disclosed in the embodiments of the present invention. A general purpose processor may be a microprocessor or any conventional processor or the like. The steps of the method disclosed in combination with the embodiments of the present invention can be directly embodied as being executed by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software module may be located in the memory 62, and the processor 61 reads the information in the memory 62, and completes the steps of the foregoing method in combination with its hardware.

Embodiment 7

The embodiment of the present invention also provides a computer storage medium. Computer instructions are stored thereon, and the instructions are implemented when executed by the processor: receiving the handover request acknowledgment information of the target base station; sending a first data packet to the target base station; the first data packet is stored and has the same Packets with preset isolation.

As an implementation manner, when the instruction is executed by the processor, it is implemented: after receiving the serial number SN request information of the target base station, send the SN to the target base station based on the SN request information; The terminal confirms the SN of the received data packet, or is the SN of the first data packet that the source base station expects the target base station to send to the terminal.

As an implementation manner, when the instruction is executed by the processor, the instruction is implemented: before receiving the SN request information of the target base station, send a second data packet to the terminal; the second data packet is stored except the first data packet. other data packets than a data packet; when receiving the first confirmation information of the terminal, send an SN status report corresponding to the first confirmation information to the target base station; wherein, the first confirmation information represents the The terminal has received the second data packet.

As an implementation manner, when the instruction is executed by the processor, it implements: sending the unsent data packet to the terminal.

As an implementation manner, when the instruction is executed by the processor, it realizes: analyzes the delay characteristics of the air interface, and compares the data packets sent to the terminal and the data sent to the target base station based on the delay characteristics and preset parameters. The isolation degree between packets is adjusted; the preset parameter includes at least one of the following parameters: a communication channel parameter with the terminal, and a service requirement parameter for a data transmission rate.

As an implementation manner, when the instruction is executed by the processor, it is implemented: after receiving the SN request information of the target base station, or after sending the SN to the target base station, the connection with the terminal is released.

Embodiment 8

The embodiment of the present invention also provides a computer storage medium. A computer instruction is stored thereon, and when the instruction is executed by the processor, it realizes: sending the SN request information to the source base station; receiving the SN of the source base station; the SN is the SN of the first data packet not confirmed by the terminal, or The source base station expects the SN of the first data packet sent by the target base station to the terminal.

As an implementation manner, when the instruction is executed by the processor, it is implemented: send a third data packet to the terminal based on the SN, where the third data packet is the first data packet that is not acknowledged by the terminal to receive, or is The source base station expects the first data packet sent by the target base station to the terminal.

As an implementation manner, when the instruction is executed by the processor, it implements: sending the unsent data packet to the terminal.

In the several embodiments provided in this application, it should be understood that the disclosed base station and method may be implemented in other manners. The base station embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods, for example, multiple units or components may be combined, or Can be integrated into another system, or some features can be ignored, or not implemented. In addition, the coupling, or direct coupling, or communication connection between the components shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be electrical, mechanical or other forms. of.

The unit described above as a separate component may or may not be physically separated, and the component displayed as a unit may or may not be a physical unit, that is, it may be located in one place or distributed to multiple network units; Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In addition, each functional unit in each embodiment of the present invention may all be integrated into one processing unit, or each unit may be separately used as a unit, or two or more units may be integrated into one unit; the above-mentioned integration The unit can be implemented either in the form of hardware or in the form of hardware plus software functional units.

Those of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by program instructions related to hardware, the aforementioned program can be stored in a computer-readable storage medium, and when the program is executed, execute It includes the steps of the above method embodiments; and the aforementioned storage medium includes: a removable storage device, a ROM, a RAM, a magnetic disk or an optical disk and other media that can store program codes.

Alternatively, if the above-mentioned integrated unit of the present invention is implemented in the form of a software function module and sold or used as an independent product, it may also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of the present invention may be embodied in the form of software products in essence or the parts that make contributions to the prior art. The computer software products are stored in a storage medium and include several instructions for A computer device (which may be a personal computer, a server, or a network device, etc.) is caused to execute all or part of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes: a removable storage device, a ROM, a RAM, a magnetic disk or an optical disk and other mediums that can store program codes.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention. should be included within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (20)

1. A switching method is applied to a source base station; characterized in that the method comprises:

a source base station receives switching request confirmation information of a target base station;

the source base station sends a first data packet to a target base station; the first data packet is a data packet which is stored by the source base station and has preset isolation with the first data packet; the first data packet is a first data packet in data packets which are stored in the source base station and are to be sent to a terminal; wherein,

the method further comprises the following steps: after receiving the SN request information of the serial number of the target base station, sending SN to the target base station based on the SN request information; the SN is the SN of the first data packet that is not acknowledged by the terminal, or the SN of the first data packet that the source base station expects the target base station to send to the terminal.

2. The method of claim 1, wherein before receiving the SN request information of the target base station, the method further comprises:

the source base station sends a second data packet to the terminal; the second data packet is other data packets stored by the source base station except the first data packet;

when receiving first confirmation information of the terminal, the source base station sends an SN (service number) status report corresponding to the first confirmation information to the target base station;

wherein the first acknowledgement information characterizes that the terminal has received the second data packet.

3. The method of claim 1, further comprising: and the source base station sends the unsent data packet to the terminal.

4. The method of claim 1, further comprising:

analyzing the time delay characteristic of an air interface, and adjusting the isolation between a data packet sent by the source base station to the terminal and a data packet sent by the source base station to the target base station based on the time delay characteristic and a preset parameter;

the preset parameters comprise at least one of the following parameters: communication channel parameters between the source base station and the terminal, and parameters required by the service for the data transmission rate.

5. The method of claim 1, further comprising: and after receiving the SN request information of the target base station or sending SN to the target base station, releasing the connection with the terminal.

6. The method of claim 1, wherein the first data packet is a first data packet of data packets stored by the source base station and to be sent to the terminal.

7. The method of claim 1, wherein the preset isolation represents a preset relative distance between a first data packet sent by the source base station to the terminal and a first data packet sent by the source base station to the target base station.

8. A switching method is applied to a target base station; characterized in that the method comprises:

the target base station sends switching request confirmation information to the source base station;

the target base station receives a first data packet sent by the source base station; the first data packet is a data packet which is stored by the source base station and has preset isolation with the first data packet; the first data packet is a first data packet in data packets which are stored in the source base station and are to be sent to a terminal; wherein

The method further comprises the following steps:

the target base station sends SN request information to a source base station;

the target base station receives the SN of the source base station; the SN is the SN of the first data packet that is not acknowledged by the terminal to receive, or the SN of the first data packet that the source base station expects the target base station to send to the terminal.

9. The method of claim 8, further comprising: and the target base station sends a third data packet to the terminal based on the SN, wherein the third data packet is a first data packet which is not confirmed to be received by the terminal or a first data packet which is expected to be sent to the terminal by the target base station for the source base station.

10. The method of claim 9, further comprising:

and the target base station sends the unsent data packet to the terminal.

11. A base station, characterized in that the base station comprises: a first receiving unit and a first transmitting unit; wherein,

the first receiving unit is used for receiving switching request confirmation information of a target base station;

the first sending unit is used for sending a first data packet to a target base station; the first data packet is a stored data packet with preset isolation from the first data packet; the first data packet is a first data packet in data packets which are stored in a source base station and are to be sent to a terminal; wherein

The first receiving unit is further configured to receive SN request information of the target base station;

the first sending unit is further configured to send an SN to the target base station based on the SN request information; the SN is the SN of the first data packet that is not acknowledged by the terminal or the SN of the first data packet that the target base station is expected to send to the terminal.

12. The base station of claim 11, wherein the first sending unit is further configured to send a second data packet to the terminal before the first receiving unit receives the SN request information of the target base station; the second data packet is other stored data packets except the first data packet;

the first receiving unit is further configured to receive first acknowledgement information of the terminal; the first confirmation information represents that the terminal has received the second data packet;

the first sending unit is further configured to send an SN status report corresponding to the first acknowledgement information to the target base station.

13. The base station of claim 11, wherein the first sending unit is further configured to send an unsent data packet to the terminal.

14. The base station according to claim 11, wherein the base station further includes an analysis processing unit, configured to analyze a delay characteristic of an air interface, and adjust an isolation between a data packet sent to the terminal and a data packet sent to the target base station based on the delay characteristic and a preset parameter; the preset parameters comprise at least one of the following parameters: and communication channel parameters between the terminal and the requirement parameters of the service on the data transmission rate.

15. The base station of claim 11, wherein the base station further comprises a release unit, configured to release the connection with the terminal after receiving the SN request information of the target base station or after sending an SN to the target base station.

16. A base station, characterized in that the base station comprises: a second transmitting unit and a second receiving unit; wherein,

the second sending unit is configured to send handover request acknowledgement information to the source base station;

the second receiving unit is configured to receive a first data packet sent by the source base station; the first data packet is a data packet which is stored by the source base station and has preset isolation with the first data packet; the first data packet is a first data packet in data packets which are stored in the source base station and are to be sent to a terminal; wherein,

the second sending unit is further configured to send SN request information to the source base station;

the second receiving unit is further configured to receive a SN of the source base station; the SN is the SN of the first data packet that is not acknowledged by the terminal, or the SN of the first data packet that the source base station expects the base station to send to the terminal.

17. The base station of claim 16, wherein the second sending unit is further configured to send a third data packet to the terminal based on the SN, where the third data packet is a first data packet that is not acknowledged by the terminal, or a first data packet that the source base station expects the base station to send to the terminal.

18. The base station of claim 16, wherein the second sending unit is further configured to send an unsent data packet to the terminal.

19. A computer-readable storage medium having stored thereon computer instructions, which when executed by a processor, carry out the steps of the handover method according to any one of claims 1 to 7;

alternatively, the instructions when executed by the processor implement the steps of the handover method of any of claims 8 to 10.

20. A base station comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor when executing the program performs the steps of the handover method of any one of claims 1 to 7;

alternatively, the processor implements the steps of the handover method of any one of claims 8 to 10 when executing the program.

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