ADAPTIVE FILE DELIVERY SYSTEM AND METHOD

• US 20090254675A1
• Filed: 06/12/2009
• Published: 10/08/2009
• Est. Priority Date: 04/07/2005
• Status: Active Grant

• Current Assignee: Opanga Networks, Inc.
• Original Assignee: Mediacast Incorporated
• Inventors: Harrang, Jeffrey P., Gibbons, David, Moinzadeh, Kamyar
• Granted Patent: US 8,812,722 B2
• Time in Patent Office: Days
• US Class Current: 709/233
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0038 Blind format detection for detection of modulation format H04L27/0012
• CPC Class Codes: H04L 1/1671 the supervisory signal being transmitted together with control information
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/19 at layers above the network layer network arrangements for networked applications for scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• CPC Class Codes: H04L 67/30 Profiles
• CPC Class Codes: H04L 67/62 Establishing a time schedule for servicing the requests
• CPC Class Codes: H04W 28/04 Error control
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 28/22 Negotiating communication rate

Abstract

An adaptive file delivery system and method transmits a data file, such as an audio-video file, over a network or collection of networks in segments, each segment transmitted during a different time period. Each time period has a transmission portion to transmit its associated file segment and a wait portion in which no further interaction with the network occurs regarding the transmitted segment. In some implementations, the duration of the transmission portion of each time period is sufficient to reach a steady-state throughput condition, which allows the traffic load status of the network or networks to be determined from rate measurements of file segment transmissions. The duration of the wait portion of each time period is at least long enough to limit the average rate of file segment transmission to adapt to network traffic load variations while causing the entire file to be delivered in a predetermined delivery deadline.

Claims

1. A method comprising:

determining a minimum transfer rate for transferring a file segment of a remaining portion of a file based in part on a determined size for the remaining portion of the file and an amount of time available to transfer the remaining portion of the file;

determining a maximum transfer rate for transferring the file segment of the remaining portion of the file based in part on the minimum transfer rate and a maximum transfer capacity of a sending system;

beginning a session to send between the sending system and a receiving system a file segment of a portion of a file yet to be received by the receiving system;

during the session, detecting that the session has stalled;

retaining state of the session at time of session stall; and

additionally requesting reception by the receiving system of an unsent portion of the file segment.

2. The method of claim 1 further including sending the unsent portion of the file segment of the remaining portion of the file from the sending system to the receiving system based upon the retained point of stall state of the session.

3. The method of claim 1 further including sending the unsent portion of the file segment of the remaining portion of the file from another sending system to the receiving system based upon the retained point of stall state of the session.

4. The method of claim 1 wherein the detecting that the session has stalled is performed by using a count-down timer.

5. The method of claim 1, further including receiving the unsent portion of the file segment;

determining an actual transfer rate that the file segment was sent from the sending system to the receiving system based in part on size of the file segment and an elapsed time between when the file segment was sent from the sending system and when the file segment was received at the receiving system;

determining a wait period based in part on the maximum transfer rate, the minimum transfer rate, and the actual transfer rate;

after receiving the file segment at the receiving system, waiting the wait period before sending an acknowledgement message from the receiving system, the acknowledgement message acknowledging receipt of the file segment by the receiving system; and

sending the acknowledgement message from the receiving system.

6. A method comprising:

beginning to send a portion of a file made up of a plurality of file segments from a sending system to a receiving system by a plurality of transmissions spaced out in time with a wait period occurring after each transmission;

determining an actual transfer rate at which at least one of the plurality of file segments was sent from the sending system to the receiving system;

determining the wait period based in part on the actual transfer rate determined for at least one file segment transmission.

during one of the file segment transmissions being performed, detecting that the file segment transmission has stalled;

retaining state of the file segment transmission at time of stall; and

additionally requesting continuation of the stalled file segment transmission.

7. The method of claim 6 further including sending the unsent portion of the file segment of the stalled transmission from the sending system to the receiving system based upon the retained state of the file segment transmission.

8. The method of claim 6 further including sending the unsent portion of the file segment of the stalled transmission from a sending system other than the sending system to the receiving system based upon the retained state of the file segment transmission.

9. The method of claim 6 wherein the detecting that the file segment transmission has stalled is performed by using a count-down timer.

10. The method of claim 9 wherein the count-down timer is started when the file segment transmission begins.

11. The method of claim 9, further including restarting the count-down timer after the file segment transmission stall has been detected.

12. The method of claim 11, further including restarting the count-down timer for a finite number of times during a time period if the unsent portion of the file segment has not been received by the receiving system during the time period.

13. The method of claim 6 for use when the file has an associated release date, the method further comprising:

sending the plurality of file segments to the receiving system in an encrypted form prior to the release date; and

on the release date allowing decryption of the encrypted file received by the receiving system.

14. The method of claim 6, further including receiving the unsent portion of the file segment of the stalled file segment transmission.

determining an actual transfer rate that the file segment was sent from the sending system to the receiving system based in part on size of the file segment and an elapsed time between when the file segment was sent from the sending system and when the file segment was received at the receiving system;

determining a wait period based in part on the maximum transfer rate, the minimum transfer rate, and the actual transfer rate;

after receiving the file segment at the receiving system, waiting the wait period before sending an acknowledgement message from the receiving system, the acknowledgement message acknowledging receipt of the file segment by the receiving system; and

sending the acknowledgement message from the receiving system.

15. A system for the transfer of a data file to a receiving system coupled to a communication network, comprising:

a sending computer system configured to send a portion of the data file made up of a plurality of file segments to the receiving system via the communication network, the sending computer system comprising;

a file storage area configured to store at least one of the plurality of file segments for transmission to the receiving system via the communication network;

a network interface controller configured to communicate with the communication network and to control the transmission of the plurality of file segments via the communication network;

a communication controller configured to determine an actual transfer rate for at least one of the plurality of file segments sent by the network interface controller of the sending system to the receiving system via the communication network and to determine a wait period for transmission of a subsequent file segment based at least in part of the determined actual transfer rate, the communication controller further configured to detect a transmission stall during the transmission of one of the plurality of file segments and to retain a state of the data file transmission at the time of the transmission of the stalled file segment.

16. The system of claim 15 wherein the communication controller is configured to determine the wait period based in part on a maximum transfer capacity of a sending system.

17. The system of claim 15 wherein the communication controller is configured to resume transmission stall during the transmission of one of the plurality of file segments that was being transmitted at the time of the transmission stall based in part upon the retained state of the data file transmission.

18. The system of claim 15 wherein the communication controller is configured to send an unsent portion of the plurality of file segments that were not transmitted from the sending system to the receiving system via the communication network prior to the detection of the transmission stall based upon the retained state of the data file transmission

19. The system of claim 15, further comprising a timer configured for control by the communication controller to detect the transmission stall.

20. The system of claim 15 for use when the data file has an associated release date wherein the communication controller is further configured to send the plurality of file segments from the network interface controller to the receiving system in an encrypted form prior to the release date, and on the release date allowing decryption of the encrypted file received by the receiving system.