ADAPTIVE BIT RATE FOR DATA TRANSMISSION

• US 20150089079A1
• Filed: 12/01/2014
• Published: 03/26/2015
• Est. Priority Date: 06/30/2010
• Status: Active Grant

• Current Assignee: Cable Television Laboratories Incorporated
• Original Assignee: Cable Television Laboratories Incorporated
• Inventors: Knittle, Curtis
• Granted Patent: US 9,819,597 B2
• Time in Patent Office: Days
• US Class Current: 709/233
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 47/25 with rate being modified by the source upon detecting a change of network conditions
• CPC Class Codes: H04L 47/263 Rate modification at the source after receiving feedback
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04N 21/2402 Monitoring of the downstream path of the transmission network, e.g. bandwidth available traffic monitoring in data switching networks H04L43/00; monitoring data switching networks utilization H04L43/0876
• CPC Class Codes: H04N 21/2662 Controlling the complexity of the video stream, e.g. by scaling the resolution or bitrate of the video stream based on the client capabilities
• CPC Class Codes: H04N 21/6373 for rate control , e.g. request to the server to modify its transmission rate flow control in packet networks H04L47/10
• CPC Class Codes: H04N 21/64769 for rate control flow control in packet networks H04L47/10
• CPC Class Codes: H04W 28/0289 Congestion control load shedding arrangements in network planning H04W16/08; performing reselection for handling the traffic H04W36/22; wireless traffic scheduling H04W72/12

Abstract

An adaptive bit rate system for use in transmitting data at adaptable bit rates. The bit rate may be adjusted according to historical behaviors and/or past operational settings, such as but not limited to adjusting a requested bit rate to a different bit rate depending the historical behavior.

Claims

1. A non-transitory computer-readable medium having a plurality of non-transitory instructions operable with an encoder to facilitate dynamically adjusting a bit rate at which data is transferred to a client, the non-transitory instructions being sufficient for:

determining a first value reflective of a plurality of bit rates at which data was previously requested to be transferred to the client over a first network, the first value being determined at least based in part on one or more prior bit rate requests made by the client;

determining a first network congestion of the first network;

determining a second value reflective of a bit rate suitable given the first network congestion; and

setting the bit rate of the encoder to approximately a third value determined as a summation of the first and second values weighted according to one of a historical influence and a present influence, the historical influence weighting the first value to have more influence than the second value and the present influence weighting the second value to have more influence than the first value.

2. The non-transitory computer-readable medium of 1 further comprising non-transitory instructions sufficient for determining the third value according to the following weighted summation of the first and second values:

third value=first value*α

+second value *β

wherein 0.5<

α

<

1 and β

=1−

α

when determining the third value according to the historical influence; and

wherein 0<

α

<

0.5 and β

=1−

α

when determining the third value according to the present influence.

3. The non-transitory computer-readable medium of 1 further comprising non-transitory instructions sufficient for determining the second value to be a selected rate value selected from a plurality of rate values identified within a bit rate map, the bit rate map associating each of the plurality of rate values with one of a plurality of network congestion values representative of network congestion, the selected rate value corresponding with the one of the plurality of rate values associated with the first network congestion.

4. The non-transitory computer-readable medium of 3 further comprising non-transitory instructions sufficient for determining the selected rate value to correspond with the one of the plurality or rate values most closely matching with the first network congestion.

5. The non-transitory computer-readable medium of 3 further comprising non-transitory instructions sufficient for determining the selected rate value to correspond with the one of the plurality of rate values matching with the first network congestion, and if no matching occurs, the next higher one of the plurality of rate values listed within the bit rate map if available otherwise the next lower.

6. The non-transitory computer-readable medium of 1 further comprising non-transitory instructions sufficient for determining the first value to be one of:

an average determined according to a rectangular window function of the plurality of bit rates at which data was previously requested to be transferred to the client; and

an average determined according to an exponential window function of the plurality of bit rates at which data was previously requested to be transferred to the client.

7. The non-transitory computer-readable medium of 1 further comprising non-transitory instructions sufficient for determining the first value according to the plurality of bit rates where at least portion of the plurality of bit rates correspond with bit rates specified in prior bit rate requests that were not correspondingly used to transfer data to the client.

8. The non-transitory computer-readable medium of 1 further comprising non-transitory instructions sufficient for:

determining a second network congestion for a second network, the second network congestion being determined following a transition of the client from the first network to the second network;

determining a fourth value reflective of a bit rate suitable given the second network congestion; and

setting the bit rate of the encoder following the transition to approximately a fifth value determined as a summation of the first and fourth values weighted according to one of the historical influence and the present influence.

9. A method of dynamically selecting a bit rate used to encode data being transmitted over a network to a client, the method comprising:

determining a current bit rate used to encode data that is currently being transmitted to the client;

determining a first amount by which the current bit is to be adjusted to compensate for network congestion of the network; and

automatically adjusting the bit rate by a second amount, the second amount being equal to a percentage P of the first amount.

10. The method of claim 9 further comprising determining the percentage P as function of a function of past bit rate adjustments.

11. The method of claim 10 further comprising determining the percentage P to be 0% in the event at least N number of bit rate changes occurred within a time period T.

12. The method of claim 9 further comprising determining the percentage P as a function of a time duration of the current bit rate.

13. The method of claim 12 further comprising determining the percentage P to be 0% in the event the time duration is less than a threshold.

14. The method of claim 9 further comprising determining the first amount to be equal to a difference between the current bit rate and a selected bit rate, the selected bit rate being selected from a plurality of bit rates mapped to network congestion values wherein the selected bit rate is the one of the plurality of bit rates mapped to a current level of network congestion.

15. The method of claim 14 further comprising automatically adjusting the bit rate by a third amount instead of the second amount in the event the second amount falls between two of the plurality of bit rates, the third amount corresponding with one of a next higher and lower one of the two of the plurality of bit rates.

16. The method of claim 15 further comprising selecting the one of the first, second, and third next lower and higher bit rate as function of one of a frequency of past bit rate adjustments and a time duration of the current bit rate.

17. A video server comprising:

a transmitting device operable to transmit video over a network to a client at a bit rate;

a controller operable to set the bit rate at which the video is transmitted based on the following formula;

bit rate=first value*α

+second value*β

wherein;

(i) the first value equals an average of a plurality of bit rates at which data was previously transferred to the client;

(ii) a second value equals a bit rate currently being requested by the client;

(iii) 0<

α

<

1;

and

(iv) β

=1−

α

.

18. The server of claim 17 wherein the controller instructs the client to select the second value from a listing of available bit rates arranged according to network congestion, the client selecting the second value based on current network congestion of the network.

19. The server of claim 18 wherein the controller sets the bit rate to the one of the listing of available bit rates that is closest to the bit rate calculated by the formula.

20. The server of claim 17 wherein the controller sets the bit rate according to 0.5<

α

<

1 when determining historical influence is desired and according to 0<

α

<

0.5 when a present influence is desired.