Method for measuring available bandwidth and communications apparatus

1. A method implemented by a transmit end, comprising:

sending, to a receive end, a first probe sequence comprising a first group of probe packets with increasing first sending rates, wherein the first probe sequence is for determining a first available bandwidth measurement result;

receiving, from the receive end, the first available bandwidth measurement result;

determining, based on the first available bandwidth measurement result, a second probe sequence comprising a second group of probe packets with increasing second sending rates, wherein a second range of the second sending rates is the same as a first range of the first sending rates, wherein the second probe sequence is for determining a second available bandwidth measurement result, wherein the second probe sequence further comprises an accurate probe sequence and an inaccurate probe sequence, and wherein a first increasing speed of third sending rates of the accurate probe sequence is less than a second increasing speed of fourth sending rates of the inaccurate probe sequence;

sending, to the receive end, the second probe sequence;

receiving, from the receive end, the second available bandwidth measurement result; and

obtaining an available bandwidth based on the second available bandwidth measurement result.

2. The method of claim 1 , wherein after receiving the second available bandwidth measurement result, the method further comprises:

determining, based on the second available bandwidth measurement result, a third probe sequence to determine a third available bandwidth measurement result, wherein a third range of third sending rates of the third probe sequence is the same as the first range;

sending the third probe sequence to the receive end; and

receiving, from the receive end, the third available bandwidth measurement result to determine the available bandwidth.

3. The method of claim 1 , wherein the available bandwidth comprises:

determining, based on a statistical value of a plurality of available bandwidth measurement results received from the receive end, the available bandwidth; or

receiving, from the receive end, the available bandwidth that is based on the statistical value.

4. The method of claim 3 , further comprising further determining the available bandwidth when a preset probe stop condition is met, wherein the preset probe stop condition comprises:

probe durations of probe sequences sent by the transmit end reaching a first preset threshold;

a quantity of available bandwidth measurement results obtained by the transmit end reaching a second preset threshold;

a difference between two successive available bandwidth measurement results being less than a third preset threshold; or

a variance of a preset quantity of a plurality of successive available bandwidth measurement results being less than a fourth preset threshold.

5. A method implemented by a receive end, comprising:

receiving, from a transmit end, a first probe sequence comprising a first group of probe packets with increasing first sending rates;

determining, based on the first probe sequence, a first available bandwidth measurement result;

sending the first available bandwidth measurement result to the transmit end to determine a second probe sequence;

receiving, from the transmit end, the second probe sequence comprising a second group of probe packets with increasing second sending rates, wherein a second range of the second sending rates is the same as a first range of the first sending rates, wherein the second probe sequence further comprises an accurate probe sequence and an inaccurate probe sequence, and wherein a first increasing speed of third sending rates of the accurate probe sequence is less than a second increasing speed of fourth sending rates of the inaccurate probe sequence;

determining, based on the second probe sequence, a second available bandwidth measurement result; and

sending, to the transmit end, the second available bandwidth measurement result to determine available bandwidth.

6. The method of claim 5 , wherein after determining the second available bandwidth measurement result and sending the second available bandwidth measurement result, the method further comprises:

receiving, from the transmit end and based on the second available bandwidth measurement result, a third probe sequence, wherein a third range of third sending rates of the third probe sequence is the same as the first range;

determining, based on the third probe sequence, a third available bandwidth measurement result; and

sending the third available bandwidth measurement result to the transmit end to determine the available bandwidth.

7. The method of claim 5 , further comprising:

further determining the available bandwidth based on a statistical value of a plurality of available bandwidth measurement results; and

sending the available bandwidth to the transmit end.

8. The method of claim 7 , further comprising further determining the available bandwidth based on the statistical value when a preset probe stop condition is met, wherein the preset probe stop condition comprises:

probe durations of probe sequences from the transmit end reaching a first preset threshold;

a quantity of available bandwidth measurement results of the transmit end reaching a second preset threshold;

a difference between two successive available bandwidth measurement results is less than a third preset threshold; or

a variance of a preset quantity of a plurality of successive available bandwidth measurement results is less than a fourth preset threshold.

9. A communications device, comprising:

a memory configured to store programming instructions; and

a processor coupled to the memory, wherein the programming instructions cause the processor to be configured to:

send, to a receive end, a first probe sequence comprising a first group of probe packets with increasing first sending rates, wherein the first probe sequence is for determining a first available bandwidth measurement result;

receive, from the receive end, the first available bandwidth measurement result;

determine, based on the first available bandwidth measurement result, a second probe sequence comprising a second group of probe packets with increasing second sending rates, wherein a second range of the second sending rates is the same as a first range of the first sending rates, wherein the second probe sequence is for determining a second available bandwidth measurement result, wherein the second probe sequence further comprises an accurate probe sequence and an inaccurate probe sequence, and wherein a first increasing speed of third sending rates of the accurate probe sequence is less than a second increasing speed of fourth sending rates of the inaccurate probe sequence;

send, to the receive end, the second probe sequence;

receive, from the receive end, the second available bandwidth measurement result; and

obtain available bandwidth based on the second available bandwidth measurement result.

10. The communications device of claim 9 , wherein the programming instructions further cause the processor to be configured to:

determine, based on the second available bandwidth measurement result, a third probe sequence to determine a third available bandwidth measurement result, wherein a third range of third sending rates of the third probe sequence is the same as the first range;

send the third probe sequence to the receive end; and

receive, from the receive end, the third available bandwidth measurement result to determine the available bandwidth.

11. The communications device of claim 9 , wherein the programming instructions further cause the processor to be configured to:

determine, based on a statistical value of a plurality of available bandwidth measurement results received from the receive end, the available bandwidth; or

receive, from the receive end, the available bandwidth that is based on the statistical value.

12. The communications device of claim 11 , wherein the programming instructions further cause the processor to be configured to further determine the available bandwidth when a preset probe stop condition is met, and wherein the preset probe stop condition comprises:

probe durations of probe sequences sent by the communications device reaching a first preset threshold;

a quantity of available bandwidth measurement results obtained by the communications device reaching a second preset threshold;

a difference between two successive available bandwidth measurement results is less than a third preset threshold; or

a variance of a preset quantity of a plurality of successive available bandwidth measurement results is less than a fourth preset threshold.

13. A communications device, comprising:

a memory configured to store programming instructions; and

a processor coupled to the memory, wherein the programming instructions cause the processor to be configured to:

receive, from a transmit end, a first probe sequence comprising a first group of probe packets with increasing first sending rates;

determine a first available bandwidth measurement result based on the first probe sequence;

send the first available bandwidth measurement result to the transmit end to determine a second probe sequence, wherein the second probe sequence further comprises an accurate probe sequence and an inaccurate probe sequence, and wherein a first increasing speed of third sending rates of the accurate probe sequence is less than a second increasing speed of fourth sending rates of the inaccurate probe sequence;

receive, from the transmit end, the second probe sequence comprising a second group of probe packets with increasing second sending rates, wherein a second range of the second sending rates is the same as a first range of the first sending rates;

determine, based on the second probe sequence, a second available bandwidth measurement result; and

send, to the transmit end, the second available bandwidth measurement result to determine available bandwidth.

14. The communications device of claim 13 , wherein the programming instructions further cause the processor to be configured to:

receive, from the transmit end and based on the second available bandwidth measurement result, a third probe sequence, wherein a third range of third sending rates of the third probe sequence is the same as the first range;

determine a third available bandwidth measurement result based on the third probe sequence; and

send the third available bandwidth measurement result to the transmit end to determine the available bandwidth.

15. The communications device of claim 13 , wherein the programming instructions further cause the processor to be configured to:

further determine the available bandwidth based on a statistical value of a plurality of available bandwidth measurement results; and

send the available bandwidth to the transmit end.

16. The communications device of claim 15 , wherein the programming instructions further cause the processor to be configured to further determine the available bandwidth based on the statistical value when a preset probe stop condition is met, and wherein the preset probe stop condition comprises:

probe duration of probe sequences sent by the transmit end reaching a first preset threshold;

a quantity of available bandwidth measurement results obtained by the transmit end reaching a second preset threshold;

a difference between two successive available bandwidth measurement results is less than a third preset threshold; or

a variance of a preset quantity of a plurality of successive available bandwidth measurement results is less than a fourth preset threshold.