Rate Adaptive Transmission of Wireless Broadcast Packets

• US 20140348049A1
• Filed: 07/31/2012
• Published: 11/27/2014
• Est. Priority Date: 07/31/2012
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Kim, Donnie H., Lee, Kang-Won, Raghavendra, Ramya, Song, Yang, Wong, Ho Yin Starsky
• Granted Patent: US 9,060,252 B2
• Time in Patent Office: Days
• US Class Current: 370/312
• CPC Class Codes: H03M 13/1515 Reed-Solomon codes
• CPC Class Codes: H03M 13/353 Adaptation to the channel
• CPC Class Codes: H03M 13/3761 using code combining, i.e. using combining of codeword portions which may have been transmitted separately, e.g. Digital Fountain codes, Raptor codes or Luby Transform [LT] codes
• CPC Class Codes: H03M 13/635 Error control coding in combination with rate matching
• CPC Class Codes: H03M 13/6527 IEEE 802.11 [WLAN]
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services

Abstract

Mechanisms are provided for broadcasting data to a plurality of receiver devices. A data broadcast transmission rate and a level of error correction to be used when broadcasting data are determined based on prior feedback received from the plurality of receiver devices. The feedback comprises channel condition information specifying conditions of one or more connections of a channel over which data was previously broadcast to the receiver devices. Data to be broadcast to the plurality of receivers is encoded in accordance with the determined level of error correction. The encoded data is broadcast at the determined data broadcast transmission rate over the channel to the plurality of receiver devices.

Claims

1. A computer program product comprising a computer readable storage medium having a computer readable program stored therein, wherein the computer readable program, when executed on a computing device, causes the computing device to:

receive, from a plurality of receiver devices, feedback information comprising channel condition information specifying conditions of one or more connections of a channel over which data was previously broadcast to the receiver devices;

determine a data broadcast transmission rate and a level of error protection to be used when broadcasting data, based on the feedback information received from the plurality of receiver devices;

encode data to be broadcast to the plurality of receiver devices in accordance with the determined level of error correction; and

broadcast the encoded data at the determined data broadcast transmission rate over the channel to the plurality of receiver devices.

2. The computer program product of claim 1, wherein the determined data broadcast transmission rate is greater than a base data transmission rate for a protocol used to perform the data broadcast.

3. The computer program product of claim 1, wherein the prior feedback received from the plurality of receiver devices comprises application-level acknowledgement packets received from the receiver devices, and wherein the data broadcast transmission rate and the level of error protection to be used when broadcasting data are determined based on an aggregate of the application-level acknowledgement packets received from the plurality of receiver devices.

4. The computer program product of claim 1, wherein each application-level acknowledgement packet specifies at least one data packet loss statistic for a corresponding connection of the channel.

5. The computer program product of claim 4, wherein the at least one data packet loss statistic is at least one of a Media Access Control (MAC) layer data packet loss statistic for a block of data or an application layer data packet loss statistic for the block of data.

6. The computer program product of claim 4, wherein the application-level acknowledgement packet is generated by a receiver device in response to a detection of a change in a data block of data received at the receiver device.

7. The computer program product of claim 1, wherein the computer readable program causes the computing device to determine the data broadcast transmission rate and the level of error protection to be used when broadcasting data, based on prior feedback received from the plurality of receiver devices, by at least one of increasing a previous data broadcast transmission rate, decreasing the previous data broadcast transmission rate, or not modifying the previous data broadcast transmission rate.

8. The computer program product of claim 1, wherein the computer readable program causes the computing device to determine the data broadcast transmission rate and the level of error protection at an application layer.

9. The computer program product of claim 1, wherein the execution of the computer readable program is transparent to a sender application providing the data to be broadcast.

10. The computer program product of claim 1, wherein the computer readable program causes the computing device to encode data to be broadcast to the plurality of receiver devices in accordance with the determined level of error correction by encoding the data using bounded LT codes (BLC) error protection encoding in which a number of data packets generated for a block of data is dynamically determined based on the channel condition information.

11. The computer program product of claim 1, wherein the computer readable program causes the computing device to determine the data broadcast transmission rate and the level of error protection to be used when broadcasting data by determining the data broadcast transmission rate and level of error protection application layer so as to increase a goodput of a worst performing receiver device in the plurality of receiver devices.

12. The computer program product of claim 1, wherein the computer readable program causes the computing device to determine the data broadcast transmission rate and the level of error protection by maximizing a goodput of a worst performing receiver device in the plurality of receiver devices by satisfying the following relationship:

max R(t)*(W(t)/(W(t)+D(t)))*(1−

mp₇(t))

s.t.mp₇(t)≦

α

where α

is an application-specific requirement for a loss ratio at time t, and R(t), W(t), and D(t) are the normal data rate of the Media Access Control (MAC) layer, a block size of the encoding, and a overhead of the encoding, respectively, and mp₇(t) is a current maximum value of a layer 7 loss ratio.

13. The computer program product of claim 1, wherein the computer readable program causes the computing device to determine the data broadcast transmission rate and the level of error protection to be used when broadcasting data, based on prior feedback received from the plurality of receiver devices, by performing a lookup operation in a predefined lookup table that correlates data broadcast transmission rates and levels of error protection for a plurality of different channel conditions.

14. The computer program product of claim 1, wherein the computer readable program further causes the computing device to:

store, prior to determining the data broadcast transmission rate and the level of error protection to be used when broadcasting data, a current broadcast transmission rate and level of error protection in a rollback data structure thereby storing rollback data transmission rate and rollback error protection level values; and

determine the data broadcast transmission rate and the level of error protection by determining if the data broadcast transmission rate and the level of error protection should be rolled back to the rollback data transmission rate and rollback error protection level values.

15. The computer program product of claim 1, wherein the computer readable program causes the computing device to determine the data broadcast transmission rate and the level of error protection by:

calculating a SameRate value representing a current best performance of a worst performing receiver device in the plurality of receiver devices should a current data broadcast transmission rate be unchanged;

calculating an IncreaseRate value representing an estimate about a performance gain by increasing the current data broadcast transmission rate to a next available higher data broadcast transmission rate;

calculating a DecreaseRate value representing an estimate of the best performance that can be achieved from the receiver devices in response to the data broadcast transmission rate being decreased to a next available lower data broadcast transmission rate;

comparing the SameRate, IncreaseRate, and DecreaseRate values to determine an appropriate action to be performed to select the data broadcast transmission rate; and

performing the determined appropriate action to thereby select the data broadcast transmission rate.

16. The computer program product of claim 15, wherein the computer readable program causes the computing device to determine the data broadcast transmission rate and the level of error protection further by:

comparing a current data rate of a receiver device with a previous data rate of the receiver device;

determining, based on the comparison of the current data rate of the receiver device with the previous data rate of the receiver device, whether or not to replace one of the IncreaseRate or DecreaseRate values with a Rollback value; and

replacing one of the IncreaseRate or DecreaseRate with the Rollback value based on the comparison and the determination as to whether or not to replace the value.

17. An apparatus, comprising:

a processor; and

a memory coupled to the processor, wherein the memory comprises instructions which, when executed by the processor, cause the processor to;

receive, from a plurality of receiver devices, feedback information comprising channel condition information specifying conditions of one or more connections of a channel over which data was previously broadcast to the receiver devices;

determine a data broadcast transmission rate and a level of error protection to be used when broadcasting data, based on the feedback information received from the plurality of receiver devices;

encode data to be broadcast to the plurality of receiver devices in accordance with the determined level of error correction; and

broadcast the encoded data at the determined data broadcast transmission rate over the channel to the plurality of receiver devices.

18. The apparatus of claim 17, wherein the determined data broadcast transmission rate is greater than a base data transmission rate for a protocol used to perform the data broadcast.

19. The apparatus of claim 17, wherein the prior feedback received from the plurality of receiver devices comprises application-level acknowledgement packets received from the receiver devices, and wherein the data broadcast transmission rate and the level of error protection to be used when broadcasting data are determined based on an aggregate of the application-level acknowledgement packets received from the plurality of receiver devices.

20. The apparatus of claim 17, wherein each application-level acknowledgement packet specifies at least one data packet loss statistic for a corresponding connection of the channel.

21. The apparatus of claim 20, wherein the at least one data packet loss statistic is at least one of a Media Access Control (MAC) layer data packet loss statistic for a block of data or an application layer data packet loss statistic for the block of data.

22. The apparatus of claim 17, wherein the instructions cause the processor to encode data to be broadcast to the plurality of receiver devices in accordance with the determined level of error correction by encoding the data using bounded LT codes (BLC) error protection encoding in which a number of data packets generated for a block of data is dynamically determined based on the channel condition information.

23. The apparatus of claim 17, wherein the instructions cause the processor to determine the data broadcast transmission rate and the level of error protection by maximizing a goodput of a worst performing receiver device in the plurality of receiver devices by satisfying the following relationship:

max R(t)*(W(t)/(W(t)+D(t)))*(1−

mp₇(t))

s.t.mp₇(t)≦

α

where α

is an application-specific requirement for a loss ratio at time t, and R(t), W(t), and D(t) are the normal data rate of the Media Access Control (MAC) layer, a block size of the encoding, and a overhead of the encoding, respectively, and mp₇(t) is a current maximum value of a layer 7 loss ratio.

24. The apparatus of claim 17, wherein the instructions cause the processor to determine the data broadcast transmission rate and the level of error protection to be used when broadcasting data, based on prior feedback received from the plurality of receiver devices, by performing a lookup operation in a predefined lookup table that correlates data broadcast transmission rates and levels of error protection for a plurality of different channel conditions.

25. The apparatus of claim 17, wherein the instructions cause the processor to determine the data broadcast transmission rate and the level of error protection by:

calculating a SameRate value representing a current best performance of a worst performing receiver device in the plurality of receiver devices should a current data broadcast transmission rate be unchanged;

calculating an IncreaseRate value representing an estimate about a performance gain by increasing the current data broadcast transmission rate to a next available higher data broadcast transmission rate;

calculating a DecreaseRate value representing an estimate of the best performance that can be achieved from the receiver devices in response to the data broadcast transmission rate being decreased to a next available lower data broadcast transmission rate;

comparing the SameRate, IncreaseRate, and DecreaseRate values to determine an appropriate action to be performed to select the data broadcast transmission rate; and

performing the determined appropriate action to thereby select the data broadcast transmission rate.