WO2018098631A1

WO2018098631A1 - Method for acquiring time difference, and base station

Info

Publication number: WO2018098631A1
Application number: PCT/CN2016/107721
Authority: WO
Inventors: 李冠臣; 刘伟
Original assignee: 华为技术有限公司
Priority date: 2016-11-29
Filing date: 2016-11-29
Publication date: 2018-06-07
Also published as: CN109997390A

Abstract

Provided in the embodiments of the present invention is a method for acquiring a time difference. The method comprises: the first base station receiving first feedback information of the user equipment with respect to first downlink data transmitted by a second base station; the first base station determining the first time when the user equipment has transmitted the first feedback information, and records the second time when the first feedback information has been received; the first base station calculating the second time, the duration of transmission of information from the user equipment to the first base station and the time difference between the first time and the second time. Using the technical solution provided in the embodiments of the present invention, base stations can also communicate therebetween according to the requirements of carrier aggregation without the need to install a timing device, such as, a GPS or a 1588V2 for synchronization, thereby reducing product costs.

Description

Method and base station for time difference acquisition

Technical field

The present invention relates to the field of wireless communication technologies, and in particular, to a method and device for acquiring time difference between base stations.

Background technique

In order to meet the service transmission rate requirement of the wireless communication system, a base station and a user equipment (UE) may aggregate a plurality of component carriers (CCs) by using carrier aggregation (CA) technology. Larger transmission bandwidth to transport traffic. The plurality of component carriers include a primary component carrier (PCC) and at least one secondary component carrier (SCC).

In order to implement the foregoing carrier aggregation, time synchronization needs to be completed between the primary component carrier (referred to as the primary carrier) and the secondary component carrier (referred to as the secondary carrier), and the synchronization time difference between the primary carrier and the secondary carrier does not exceed 32.47 microseconds. In the case of carrier aggregation across a base station (multiple base stations), a global positioning system (global positioning system) may be installed between a base station where the primary carrier is located (hereinafter referred to as the first base station) and a base station where the secondary carrier is located (hereinafter referred to as the second base station). GPS) or use the 1588V2 clock lamp timing device defined by the Institute of Electrical and Electronics Engineers (IEEE) to guarantee the component carrier between the multiple base stations. Time synchronization.

However, when the cross-base station carrier aggregation service is enabled, GPS and 1588V2 timing devices are products that require additional procurement, and the installation of these two products requires the modification and upgrade of the wireless communication system, which undoubtedly increases the cost and deployment time. .

Summary of the invention

The embodiment of the invention discloses a time difference acquisition method and a base station, which does not need time synchronization of component carriers between base stations, and saves cost and deployment time caused by synchronization of installing GPS or 1588V2 timing devices.

A first aspect of the embodiments of the present invention provides a time difference acquisition method, including:

The first base station receives first feedback information of the first downlink data that is sent by the user equipment to the second base station, where the first feedback information indicates whether the first downlink data is correctly received;

Determining, by the first base station, the first time that the user equipment sends the first feedback information, and recording a second time when the first feedback information is received;

The first base station calculates the second time, the information transmission duration from the user equipment to the first base station, and a time difference between the first times.

In the implementation manner of the first aspect, the user equipment feeds back downlink data sent by the second base station according to an existing feedback mechanism, where the first base station needs to send feedback, feedback time, and feedback. Information transmission time, come Determining the time difference between the first base station and the second base station does not require installing a GPS or 1588V2 timing device, thereby saving product cost and deployment time.

In conjunction with the first aspect, in a first possible implementation manner of the first aspect, the method further includes:

Transmitting, by the first base station, second downlink data to the user equipment, and recording a third time that the first base station sends the second downlink data;

Receiving, by the first base station, second feedback information of the second downlink data that is sent by the user equipment to the first base station, and recording a fourth time of receiving the second feedback information, where the The second feedback information indicates whether the second downlink data is correctly received;

Determining, by the first base station, the information transmission duration of the user equipment to the first base station according to the third time and the fourth time.

In a first possible implementation manner of the first aspect, the first base station determines that the user equipment is located by sending downlink data to the user equipment and receiving feedback on the downlink data from the user equipment. The information transmission duration of the first base station is described.

With reference to the first aspect, in a second possible implementation manner of the first aspect, the method further includes:

The first base station sends second downlink data to the user equipment;

Receiving, by the first base station, second feedback information of the second downlink data by the user equipment, and recording a fourth time of receiving the second feedback information, where the second feedback information indicates the first Whether the second downlink data is correctly received;

Receiving, by the user equipment, the fifth time from the user equipment that the user equipment sends the second feedback information;

The first base station determines that the information transmission duration of the user equipment to the first base station is the fourth time minus the fifth time.

In a second possible implementation manner of the first aspect, the fourth time that the first base station receives the second feedback information and the fifth time that the user equipment sends the second feedback information may determine And the information transmission duration of the user equipment to the first base station.

In combination with the first aspect to the second possible implementation manner of the first aspect, in a third possible implementation manner of the first aspect, the first base station determines that the user equipment sends the first feedback information The first time, including:

Receiving, by the first base station, a first notification sent by the second base station, where the first notification indicates a sixth time that the second base station sends the first downlink data;

The first base station determines that the first time is the sixth time plus a pre-configured feedback time interval.

In a third possible implementation manner of the first aspect, when the second base station sends the first downlink data to the user equipment, the second base station notifies the first base station to send the first downlink The sixth time of the line data. According to the existing feedback timing requirement that the first base station and the second base station perform carrier aggregation, the feedback of the downlink data sent by the user equipment to the second base station is that the second base station sends downlink data in advance. The configured feedback time interval is sent to the first base station. The pre-configured feedback time interval is known to the first base station. Thus, The first base station may calculate, according to the pre-configured feedback time interval, a first time that the user equipment sends the first feedback information.

In conjunction with the third possible implementation of the first aspect, in a fourth possible implementation of the first aspect, the method further includes:

The first base station configures, to the user equipment, the first feedback information from a time when the first notification is received to when the first feedback information is received.

Before the first base station does not know the time difference between the first base station and the second base station, the first base station does not know at which time the user equipment receives the first feedback information. . Therefore, the first base station can continuously detect each time after the second base station notifies the sending time of the first downlink data of the first base station to the time when the first feedback information is received. Time to receive the first feedback information. Optionally, the user equipment is only allocated to the user equipment during the period of time, and is not allocated to other user equipments before the time difference is obtained.

With reference to any one of the first aspect to the fourth possible implementation of the first aspect, in a fifth possible implementation manner of the first aspect, the method further includes:

Receiving, by the first base station, a second notification of the second base station, where the second notification indicates a sending time of the third downlink data sent by the second base station in a timing of the second base station;

Determining, by the first base station, a sending time in a timing of the first base station where the third downlink data is located, according to the time difference;

The first base station is configured to send, to the user equipment, a preset duration of time from a sending time in a timing of the first base station where the third downlink data is located. The third feedback information of the third downlink data is used to indicate whether the third downlink data is correctly received.

After the first base station acquires the time difference between the first base station and the second base station, the first may be made even if the timing between the first base station and the second base station is asynchronous. Obtaining, by the base station, the time when the second base station sends the downlink data at the timing of the first base station, and the time when the user equipment sends the downlink data feedback according to the timing of the second base station, to reach the foregoing Similar system performance in the case where the second base station and the first base station are synchronized.

A second aspect of the embodiments of the present invention provides a first base station, where the first base station includes a processor, a transmitter, and a receiver. The processor may perform the processing, determining, and the like of the first base station in the first aspect and its various possible implementation manners; the transmitter is configured to perform the foregoing in the first aspect and each possible implementation manner thereof The transmitting action of the first base station; the receiver is configured to perform the receiving action of the first base station in the first aspect and its various possible implementation manners. The first base station provided by the second aspect can implement similar or identical effects in the first aspect and its various possible implementation manners, and details are not described herein again.

DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are some embodiments of the present invention. Those skilled in the art can obtain their own drawings according to these drawings without paying creative labor. His drawings.

1 is a schematic diagram of a wireless communication system according to an aspect of an embodiment of the present invention;

2 is a schematic diagram of system interaction of a time difference acquisition method according to an aspect of an embodiment of the present invention;

FIG. 3 is a schematic diagram of information transmission interaction between a first base station and a user equipment according to an embodiment of the present disclosure;

4 is a schematic flowchart of a data feedback method according to an aspect of an embodiment of the present disclosure;

FIG. 5 is a schematic structural diagram of a first base station according to an aspect of an embodiment of the present invention.

detailed description

In the wireless communication system shown in FIG. 1 , the carriers of multiple base stations are aggregated to provide service services for the same user equipment, which enhances the maximum bandwidth of the transmission, so that the user equipment can obtain a better service service experience. The plurality of base stations include a first base station and a second base station, wherein the first base station is configured with one primary carrier and at least one secondary carrier, and the second base station is configured with at least one secondary carrier. The first base station and the second base station are connected through an X2 interface or an internet protocol (IP) interface. Generally, the first base station and the second base station each have different timings, respectively, the first base station and the second base station It is asynchronous in time. When the user equipment initially accesses the wireless communication system, the user equipment establishes a connection with the first base station through a primary carrier. The first base station further determines whether to perform carrier aggregation of multiple (including two) base stations to provide service services for the user equipment. If the first base station determines to perform carrier aggregation between multiple base stations, the first base station sends configuration information of the secondary carrier, for example, the frequency of the secondary carrier, to the user equipment by using the primary carrier. The user equipment establishes a connection with the second base station according to the configuration information of the secondary carrier, thereby further implementing data transmission under carrier aggregation. The time synchronization requirement of the current carrier aggregation is that the time difference between the timing of the primary carrier of the first base station and the timing of the secondary carrier of the second base station does not exceed a certain threshold, for example, 32.47 microseconds. In fact, if the time difference between the first base station and the second base station can be obtained, the primary carrier of the first base station and the secondary carrier of the second base station can implement the synchronization requirement even if the synchronization requirement is not met. Carrier aggregation of the primary carrier and the secondary carrier.

An embodiment of the present invention provides a method for time difference acquisition, as shown in FIG. 2 . In the embodiment of the present invention, in the process of performing carrier aggregation of the first base station and the second base station, the user equipment establishes an uplink and downlink connection with the first base station by using the primary carrier of the first base station, and The secondary carrier of the second base station is used to establish an uplink and downlink connection with the second base station. It should be noted that, because the timing between the first base station and the second base station may be asynchronous, in the implementation manner, the first base station performs information transmission and reception according to the timing of the first base station. The second base station according to the second base station Regularly send and receive information and processing.

201. The user equipment receives first downlink data sent by the second base station.

In 201, the first downlink data sent by the second base station to the user equipment may be any type of service data. In the embodiment of the present invention, the sending of the first downlink data is used to acquire the time difference between the first base station and the second base station, and the sending of any type of service data does not affect the implementation of the present invention. Optionally, the second base station may send the first downlink data to the user equipment under the indication of the first base station, where the indication of the first base station may include the first downlink At least one type of information of a type of row data and an identifier of the user equipment.

202. The user equipment sends first feedback information about the first downlink data to the first base station, where the first feedback information indicates whether the first downlink data is correctly received.

In 202, the user equipment may use the Hybrid Automatic Repeat ReQuest (HARQ) mechanism to send the first feedback information, for example, if the user equipment is compatible with the existing 3GPP protocol. If the first downlink data is not correctly received, the first base station notifies the second base station to retransmit the first downlink data. In the embodiment of the present invention, the final purpose of the sending of the first feedback information is to obtain a time difference between the first base station and the second base station, and therefore, if the first feedback information indicates The first downlink data is not correctly received, and the first base station may not retransmit the first downlink data by notifying the second base station according to the HARQ mechanism.

203. The first base station determines a first time (t1) that the user equipment sends the first feedback information.

204. The first base station records a second time (t2) of receiving the first feedback information.

205. The first base station calculates a time difference between the second time, an information transmission duration from the user equipment to the first base station, and the first time.

In 205, as a possible implementation manner, as shown in FIG. 3, the information transmission process of the first base station and the user equipment, the information transmission duration from the user equipment to the first base station may be as follows: Ways to determine.

(1) determining a first possible implementation manner of the information transmission duration of the user equipment to the first base station:

The first base station sends second downlink data to the user equipment, and records a third time (t3) that the first base station sends the second downlink data. Receiving, by the first base station, second feedback information of the second downlink data that is sent by the user equipment to the first base station, and recording a fourth time (t4) of receiving the second feedback information, where The second feedback information indicates whether the second downlink data is correctly received.

The first base station determines, according to the third time (t3) and the fourth time (t4), the information transmission duration of the user equipment to the first base station. For example, it may be assumed here that the first base station sends the second downlink data to the user equipment, and the information transmission duration of the second feedback information sent by the user equipment to the first base station is the same, and the slave user equipment The information to the first base station The transmission duration is equal to the fourth time minus the third time and then divided by two.

(2) determining a second possible implementation manner of the information transmission duration of the user equipment to the first base station:

The first base station sends second downlink data to the user equipment. The first base station receives second feedback information of the second downlink data sent by the user equipment to the first base station, and records a fourth time (t4) of receiving the second feedback information; The first base station further receives, from the user equipment, a fifth time (t5) that the user equipment sends the second feedback information, for example, when the user equipment sends the second feedback information, The feedback information is sent by the fifth time, and the fifth time is sent to the first base station. The first base station determines that the information transmission duration of the user equipment to the first base station is the fourth time minus the fifth time.

In 203, the first base station determines, by the first base station, the first time that the user equipment receives the first downlink data sent by the second base station, where the first base station receives the first a first notification sent by the second base station, where the first notification indicates a sixth time that the second base station sends the first downlink data; and the first base station determines that the first time is the sixth Time plus pre-configured feedback interval. Optionally, in order to ensure that the first base station does not receive the first feedback information because the time difference between the first base station and the second base station is large, the first base station may receive the first The first feedback information is sent to the user equipment when a notification is received to receive the first feedback information. The first base station and the second according to the provisions of the existing 3GPP protocol The timing of the base station may be in units of subframes (one subframe includes two slots), and the pre-configured feedback time interval is 4 subframes. In other words, the first base station is offset by 4 subframes after the subframe in which the sixth time is located, and is determined to be a subframe in the timing of the second base station where the first time is located.

In the embodiment of the present invention, in order to obtain the time difference, the user equipment may implement receiving the first downlink data and the second downlink data by adding a buffer. If the measurement error of the time difference does not exceed one time slot (for example, 0.5 milliseconds), the buffer is set to be capable of accepting the first downlink data and the second downlink data having a maximum delay of one time slot.

In the embodiment of the present invention, the first time is a time when the user equipment sends the first feedback information of the downlink data to the second base station, and the second time is that the first base station receives the A time for feedback. If the first base station and the second base station are synchronized, the difference between the second time and the first time is equal to the information transmission duration from the user equipment to the first base station, and may be directly followed. There is a carrier aggregation method defined by the 3rd partnership project (3GPP) for carrier aggregation of the first base station and the second base station. If the first base station and the second base station are non-synchronized (for example, the time difference between the first base station and the second base station is greater than 32.47 microseconds), the technical solution provided by the embodiment of the present invention is used to obtain The time difference between the first base station and the second base station, and the scheduling between the first base station and the second base station according to the time difference may also implement the first base station and the second base station. Primary and secondary carrier aggregation, and it is no longer necessary to install GPS or 1588V2 timing The device maintains time synchronization and then performs carrier aggregation. For example, in order to implement carrier aggregation, if the timing of the first base station leads the second base station, the first base station may delay transmitting the time difference to the scheduled data when scheduling data, or the second base station Processing, by the time difference, the data scheduled by the first base station; if the timing of the first base station is later than the second base station, the first base station may send the scheduled data in advance by the time difference when scheduling data Or the second base station processes the data scheduled by the first base station by the time difference.

The first base station may determine a time difference between the first base station and the second base station by providing the content as shown in the embodiments shown in FIG. 2 and FIG. 3. Further, another aspect of the embodiments of the present invention provides a data feedback transmission method, as shown in the flow chart of the data feedback method shown in FIG. 4, which may be performed by using the time difference determined in the foregoing embodiment. Data feedback between the second base station and the user equipment, thereby achieving the effect of carrier aggregation.

401. The second base station has third downlink data that is sent to the user equipment, and the second base station sends a second notification to the first base station, where the second notification indicates that the second base station sends The transmission time of the third downlink data in the timing of the second base station.

In 401, the sending time of the third downlink data in the timing of the second base station may be indicated in the form of a subframe number, and the concept of the subframe may refer to the 3GPP protocol.

402. The first base station receives the second notification of the second base station, and determines, according to the time difference determined in the foregoing embodiment, where the third downlink data is located. The transmission time in the timing of the first base station.

In 402, the first base station determines, according to the time difference, that a transmission time of the third downlink data in a timing of the second base station is offset from the time difference or backwards by the time difference. The transmission time of the third downlink data in the timing of the first base station. When the timings of the first base station and the second base station are in units of subframes, the sending time of the third downlink data in the timing of the first base station is sent by the second base station. The subframe indicated by the three downlink data is offset forward by the subframe in which the time difference is located or the subframe in which the time difference is offset backward.

403. The first base station sends, to the user equipment, third feedback information of the third downlink data to the user equipment for a preset duration of time in a sending time of the first base station where the third downlink data is located. The first base station is configured to indicate whether the third downlink data is correctly received.

If the measurement error of the time difference is not more than one time slot (0.5 milliseconds), the sending time of the third downlink data in the timing of the first base station is the third downlink data sent by the second base station. The indicated subframe is shifted backward by one subframe or forward by one subframe. The first base station may reserve, for the user equipment, a feedback resource for the third feedback information for the user equipment in the offset subframe, and wait for the third feedback information to be sent.

Optionally, after the 403, the first base station may further notify the subframe number of the feedback resource of the third feedback information reserved by the second base station for the user equipment, so that the second The base station adjusts the timing of transmitting the downlink data again.

According to the technical solution provided by the embodiment of the present invention, after the second base station sends the downlink data to the user equipment, the first base station may accurately determine, according to the time difference, the downlink data of the user equipment. Feedback time to complete carrier aggregation.

The embodiment of the present invention further provides an apparatus for implementing the foregoing embodiment of the method shown in FIG. 2 to FIG. 4, where the apparatus is the foregoing first base station, and the duplicate content in the foregoing embodiment may not be further described in this embodiment. As shown in FIG. 5, the first base station includes a processor 501 and a receiver 502. In a specific product implementation, the apparatus may further include a bus 504 for connecting the processor 501, the transmitter 503, and the receiver 502, and for storing processing information in the processor 501. The information to be transmitted in the transmitter 503 or the received information in the receiver 502 is described.

The processor 501 is configured to determine a first time that the receiving user equipment receives the first downlink data sent by the second base station, and the receiver 502 is configured to receive the first feedback of the user equipment to the first downlink data. The processor is configured to record a second time when the first feedback information is received, where the first feedback information indicates whether the first downlink data is correctly received; and the processor 501 is further configured to calculate The second time, a length of information transmission from the user equipment to the first base station, and a time difference between the first times.

Optionally, the first base station further includes a transmitter 503, where the transmitter 503 is configured to send the second downlink data to the user equipment.

As an implementation manner, the processor 501 is further configured to record the first base The third time when the station sends the second downlink data. Correspondingly, the receiver 502 is further configured to receive second feedback information of the second downlink data that is sent by the user equipment to the first base station, where the processor 501 is further configured to record, receive the And a fourth time of the feedback information. The processor 501 is configured to determine, according to the third time and the fourth time, the information transmission duration of the user equipment to the first base station.

As another implementation manner, the receiver 502 is configured to receive second feedback information of the second downlink data sent by the user equipment to the first base station, where the processor 501 is further configured to record and receive a fourth time of the second feedback information; the receiver 503 is further configured to receive, by the user equipment, a fifth time that the user equipment sends the second feedback information; the processor 501 is configured to determine The information transmission duration of the user equipment to the first base station is the fourth time minus the fifth time.

In the foregoing implementation manner, the receiver 502 is further configured to receive a first notification sent by the second base station, where the first notification indicates a sixth time that the second base station sends the first downlink data. The processor 501 is configured to determine that the first time is the sixth time plus a pre-configured feedback time interval. Further, the processor 501 is further configured to send, to the user equipment, the first feedback information from a time when the first notification is received to when the first feedback information is received.

Further, the receiver 502 is further configured to receive a second notification by the second base station, where the second downlink information that is sent by the second base station is a sending time in the timing of the second base station; the processor 501 is further configured to determine, according to the time difference, a sending time in a timing of the first base station where the third downlink data is located; the processor 501 And the third feedback information for the third downlink data is sent to the user equipment, where the third feedback information is configured, where the sending time of the first base station where the third downlink data is located, is configured. The feedback information is used to indicate whether the third downlink data is correctly received.

The time difference between the first base station and the second base station is obtained by using the first base station provided by the embodiment of the present invention, and the data scheduling between the first base station and the second base station according to the time difference may also be performed. A primary/secondary carrier aggregation of the first base station and the second base station is implemented, and it is no longer necessary to install a GPS or a 1588V2 timing device to maintain time synchronization and then perform carrier aggregation.

A person skilled in the art can understand that all or part of the process of implementing the above embodiment method can be completed by a computer program to instruct related hardware, and the program can be stored in a computer readable storage medium. When executed, the flow of an embodiment of the methods as described above may be included. The foregoing storage medium includes various media that can store program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.

The above embodiments are only illustrative of the preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, and those skilled in the art can understand all or part of the processes for implementing the above embodiments, and according to the claims of the present invention. Equivalent changes are still within the scope of the invention.

Claims

A time difference acquisition method, comprising:

The first base station receives first feedback information of the first downlink data that is sent by the user equipment to the second base station, where the first feedback information indicates whether the first downlink data is correctly received;

Determining, by the first base station, the first time that the user equipment sends the first feedback information, and recording a second time when the first feedback information is received;

The first base station calculates the second time, the information transmission duration from the user equipment to the first base station, and a time difference between the first times.
The method of claim 1 further comprising:

Transmitting, by the first base station, second downlink data to the user equipment, and recording a third time that the first base station sends the second downlink data;

Receiving, by the first base station, second feedback information of the second downlink data that is sent by the user equipment to the first base station, and recording a fourth time of receiving the second feedback information, where the The second feedback information indicates whether the second downlink data is correctly received;

Determining, by the first base station, the information transmission duration of the user equipment to the first base station according to the third time and the fourth time.
The method of claim 1 further comprising:

The first base station sends second downlink data to the user equipment;

Receiving, by the first base station, second feedback information of the second downlink data that is sent by the user equipment to the first base station, and recording a fourth time of receiving the second feedback information, where the The second feedback information indicates whether the second downlink data is correctly received;

Receiving, by the user equipment, the fifth time from the user equipment that the user equipment sends the second feedback information;

The first base station determines that the information transmission duration of the user equipment to the first base station is the fourth time minus the fifth time.
The method according to any one of claims 1-3, wherein the determining, by the first base station, the first time that the user equipment sends the first feedback information comprises:

Receiving, by the first base station, a first notification sent by the second base station, where the first notification indicates a sixth time that the second base station sends the first downlink data;

The first base station determines that the first time is the sixth time plus a pre-configured feedback time interval.
The method of claim 4, wherein the method further comprises:

The first base station configures, to the user equipment, the first feedback information from a time when the first notification is received to when the first feedback information is received.
The method of any of claims 1-5, further comprising:

Receiving, by the first base station, a second notification of the second base station, where the second notification indicates a sending time of the third downlink data sent by the second base station in a timing of the second base station;

Determining, by the first base station, a sending time in a timing of the first base station where the third downlink data is located, according to the time difference;

The first base station is configured to send, to the user equipment, third feedback information about the third downlink data, by using a predetermined duration of time from a sending time of the first base station where the third downlink data is located, where The third feedback information is used to indicate whether the third downlink data is correctly received.
A first base station, comprising:

a processor, configured to determine a first time when the receiving user equipment receives the first downlink data sent by the second base station;

a receiver, configured to receive first feedback information about the first downlink data by the user equipment, where the processor is configured to record a second time when the first feedback information is received, where the first feedback is The information indicates whether the first downlink data is correctly received;

The processor is further configured to calculate the second time, a time length of information transmission from the user equipment to the first base station, and a time difference between the first time.
The base station according to claim 7, further comprising: a transmitter, configured to send second downlink data to the user equipment;

The processor is further configured to record, by the first base station, the second downlink number According to the third time; among them,

The receiver is further configured to receive second feedback information of the second downlink data sent by the user equipment to the first base station, where the processor is further configured to record, by using the second feedback information Four times; wherein the second feedback information indicates whether the second downlink data is correctly received;

The processor is configured to determine, according to the third time and the fourth time, the information transmission duration of the user equipment to the first base station.
The base station according to claim 8, further comprising: a transmitter, configured to send second downlink data to the user equipment;

The receiver is configured to receive second feedback information of the second downlink data that is sent by the user equipment to the first base station, where the processor is further configured to record a fourth time that the second feedback information is received. Wherein the second feedback information indicates whether the second downlink data is correctly received;

The receiver is further configured to receive, by the user equipment, a fifth time that the user equipment sends the second feedback information;

The processor is configured to determine that the information transmission duration of the user equipment to the first base station is the fourth time minus the fifth time.
A base station according to any one of claims 7-9, characterized in that

The receiver is further configured to receive a first notification sent by the second base station, where the first notification indicates a sixth time that the second base station sends the first downlink data;

The processor is configured to determine that the first time is the sixth time plus Pre-configured feedback interval.
The base station according to claim 10, characterized in that

The processor is further configured to send, to the user equipment, the first feedback information from a time when the first notification is received to when the first feedback information is received.
A base station according to any one of claims 7-11,

The receiver is further configured to receive a second notification of the second base station, where the second notification indicates a sending time of the third downlink data sent by the second base station in a timing of the second base station;

The processor is further configured to determine, according to the time difference, a sending time in a timing of the first base station where the third downlink data is located;

The processor is further configured to send, to the user equipment, third feedback information about the third downlink data, by using a predetermined duration of time from a sending time in a timing of the first base station where the third downlink data is located, The third feedback information is used to indicate whether the third downlink data is correctly received.