Data transmission methods, apparatuses, base stations and servers

1. A method implemented by one or more computing devices, the method comprising:

determining a system time difference between a first base station and a second base station based on an actual transmission time length of a wireless frame and a measured transmission time length of the wireless frame, the actual transmission time length of the wireless frame being at least based on a half of a time length of a round trip of the wireless frame between the first base station and the second base station, the measured transmission time length of the wireless frame being at least based on a sending time of the wireless frame at the first base station and a receiving time of the wireless frame at the second base station;

modifying a sending time of first data according to the system time difference, the sending time of the first data being determined according to a receiving time of second data at the first base station; and

sending the first data from the second base station according to the modified sending time of the first data.

2. The method of claim 1 , wherein determining the system time difference between the first base station and the second base station based on the actual transmission time length of the wireless frame comprises determining a difference between the measured transmission time length taken by the wireless frame from being sent by the first base station to being received by the second base station and the actual transmission time length as the system time difference between the first base station and the second base station.

3. The method of claim 2 , wherein the wireless frame comprises reference time information, and the reference time information comprises a sending time of the reference time information.

4. The method of claim 3 , wherein determining the difference between the measured transmission time length taken by the wireless frame from being sent by the first base station to being received by the second base station and the actual transmission time length as the system time difference between the first base station and the second base station comprises:

obtaining a sending time at which the first base station sends the reference time information and a receiving time at which the second base station receives the reference time information;

determining the measured transmission time length based on the sending time of sending the reference time information and the receiving time of receiving the reference time information; and

using the difference between the measured transmission time length and the actual transmission time length as the system time difference between the first base station and the second base station.

5. The method of claim 2 , wherein determining the difference between the measured transmission time length taken by the wireless frame from being sent by the first base station to being received by the second base station and the actual transmission time length as the system time difference between the first base station and the second base station further comprises determining the actual transmission time length taken by the wireless frame from being sent by the first base station to being received by the second base station.

6. The method of claim 5 , wherein determining the actual transmission time length taken by the wireless frame from being sent by the first base station to being received by the second base station comprises:

determining the time length of the round trip of the wireless frame between the first base station and the second base station; and

determining the half of the time length of the round-trip as the actual transmission time length.

7. The method of claim 1 , wherein determining the system time difference between the first base station and the second base station based on the actual transmission time length of the wireless frame comprises receiving the system time difference between the first base station and the second base station issued by a server.

8. The method of claim 1 , further comprising determining the sending time of the first data according to the receiving time of the second data prior to modifying the sending time of the first data according to the system time difference.

9. The method of claim 8 , further comprising receiving the receiving time of the second data notified by the first base station prior to determining the sending time of the first data according to the receiving time of the second data.

10. The method of claim 1 , further comprising receiving the sending time of the first data sent by a server, and the sending time of the first data being determined according to the receiving time of the second data at the first base station prior to modifying the sending time of the first data according to the system time difference.

11. The method of claim 1 , wherein: prior to determining the system time difference between the first base station and the second base station based on the actual transmission time length of the wireless frame, the method further comprises selecting the second base station for sending the first data.

12. One or more computer readable media storing executable instructions that, when executed by one or more processors of a first base station, cause the one or more processors to perform acts comprising:

sending reference time information by the first base station to a second base station;

obtaining a system time difference between the first base station and the second base station based on an actual transmission time length of the reference time information and a measured transmission time length of the reference time information, the actual transmission time length of the reference time information being at least based on a half of a time length of a round trip of the reference time information between the first base station and the second base station, the measured transmission time length of the wireless frame being at least based on a sending time of the reference time information at the first base station and a receiving time of the reference time information at the second base station; and

modifying a sending time of first data sent by the second base station according to the system time difference, wherein the sending time of the first data is being determined based on a receiving time of second data at the first base station.

13. The one or more computer readable media of claim 12 , wherein sending the reference time information by the first base station to the second base station comprises sending the reference time information to at least one base station in a same communication area.

14. The one or more computer readable media of claim 12 , the acts further comprising receiving the second data before sending the reference time information by the first base station to the second base station.

15. The one or more computer readable media of claim 14 , the acts further comprising determining the second base station selected by a server for sending the first data.

16. An apparatus comprising:

one or more processors; and

memory storing executable instructions that, when executed by the one or more processors, cause the one or more processors to perform acts comprising:

determining a system time difference between a first base station and a second base station based on an actual transmission time length of a wireless frame and a measured transmission time length of the wireless frame, the actual transmission time length of the wireless frame being at least based on a half of a time length of a round trip of the wireless frame between the first base station and the second base station, the measured transmission time length of the wireless frame being at least based on a sending time of the wireless frame at the first base station and a receiving time of the wireless frame at the second base station;

modifying a sending time of first data according to the system time difference, the sending time of the first data being determined according to a receiving time of second data at the first base station; and

sending the first data from the second base station according to the modified sending time of the first data.

17. The apparatus of claim 16 , wherein determining the system time difference between the first base station and the second base station based on the actual transmission time length of the wireless frame comprises determining a difference between the measured transmission time length taken by the wireless frame from being sent by the first base station to being received by the second base station and the actual transmission time length as the system time difference between the first base station and the second base station.

18. The apparatus of claim 17 , wherein the wireless frame comprises reference time information, and the reference time information comprises a sending time of the reference time information.

19. The apparatus of claim 18 , wherein determining the difference between the measured transmission time length taken by the wireless frame from being sent by the first base station to being received by the second base station and the actual transmission time length as the system time difference between the first base station and the second base station comprises:

obtaining a sending time at which the first base station sends the reference time information and a receiving time at which the second base station receives the reference time information;

determining the measured transmission time length based on the sending time of sending the reference time information and the receiving time of receiving the reference time information; and

using the difference between the measured transmission time length and the actual transmission time length as the system time difference between the first base station and the second base station.

20. The apparatus of claim 19 , wherein determining the difference between the measured transmission time length taken by the wireless frame from being sent by the first base station to being received by the second base station and the actual transmission time length as the system time difference between the first base station and the second base station further comprises determining the actual transmission time length taken by the wireless frame from being sent by the first base station to being received by the second base station.