Systems and methods for configuring a delay based scheduler for an access node

• US 9,923,836 B1
• Filed: 11/21/2014
• Issued: 03/20/2018
• Est. Priority Date: 11/21/2014
• Status: Active Grant

• Current Assignee: Sprint Spectrum LLC (Deutsche Telekom AG)
• Original Assignee: Sprint Spectrum LP (Deutsche Telekom AG)
• Inventors: Vivanco, Daniel
• Primary Examiner(s): Cho, Un C
• Assistant Examiner(s): Rahman, Shah
• Application Number:
  US14/550,150
• Time in Patent Office: 1,215 Days
• Field of Search: 370230
• CPC Class Codes: H04L 47/11 Identifying congestion
• CPC Class Codes: H04L 47/12 Avoiding congestion; Recovering from congestion
• CPC Class Codes: H04L 47/2475 for supporting traffic characterised by the type of applications
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames
• CPC Class Codes: H04L 47/564 Attaching a deadline to packets, e.g. earliest due date first

Abstract

Systems and methods are described for configuring a delay based scheduler for an access node. A plurality of packets may be received at an access node, where at least a first packet is associated with an application running on a wireless device in communication with the access node. The plurality of packets may be inspected to determine that one or more of the packets associated with the application are marked, where the mark indicates network congestion. A remaining time for the first packet may be calculated based on a packet delay budget associated with the running application and the determination that one or more of the packets associated with the application are marked. The first packet may then be scheduled for transmission to the wireless device, using a delay based scheduler, based on the calculated remaining time.

Claims

1. A method for configuring a delay based scheduler for an access node, the method comprising:

receiving, at an access node, a plurality of packets, wherein at least a first packet is associated with an application running on a wireless device in communication with the access node;

inspecting the plurality of packets to determine that one or more of the packets associated with the application are marked, wherein the mark indicates network congestion;

determining a number of marked packets associated with the application received at the access node within a time period;

calculating a remaining time for the first packet based on a packet delay budget associated with the running application, a bias factor that is calculated based on the determined number of marked packets received at the access node, and an estimated delay for transmission from the access node to the wireless device, wherein the bias factor is subtracted from the remaining time for the first packet in response to the received number of marked packets associated with the application; and

scheduling, using a delay based scheduler, the first packet for transmission based on the calculated time remaining, and transmitting the first packet to the wireless device based on the scheduling.

2. The method of claim 1, wherein calculating the remaining time for the first packet comprises summing the estimated delay for transmission from the access node to the wireless device and the bias factor, and subtracting the sum from the packet delay budget associated with the running application.

3. The method of claim 2, wherein scheduling, using a delay based scheduler, the first packet for transmission to the wireless devices based on the calculated time remaining further comprises:

dropping the first packet when the sum of the estimated delay for transmission from the access node to the wireless device and the bias factor is greater than the packet delay budget associated with the running application.

4. The method of claim 1, wherein the calculated bias factor is directly proportional to the number of marked packets associated with the application received within the time period.

5. The method of claim 4, wherein the calculated bias factor is reduced when a marked packet associated with the application has not been received within a threshold time.

6. The method of claim 2, further comprising:

time stamping each packet received at the access node; and

scheduling, using the delay based scheduler, the first packet for transmission to the wireless device based on the time stamp for the first packet.

7. The method of claim 2, wherein the running application communicates using a real-time transport control protocol (RTCP) and a marked packet comprises an explicit congestion notification (ECN) mark.

8. A system for configuring a delay based scheduler for an access node, the system comprising:

a processing node with a processor configured to;

receive, at an access node, a plurality of packets, wherein at least a first packet is associated with an application running on a wireless device in communication with the access node;

inspect the plurality of packets to determine that one or more of the packets associated with the application are marked, wherein the mark indicates network congestion;

calculate a remaining time for the first packet based on a packet delay budget associated with the running application, a bias factor that is calculated based on a number of marked packets received at the access node, and an estimated delay for transmission from the access node to the wireless device, wherein the bias factor is subtracted from the remaining time for the first packet in response to the one or more marked packets associated with the application; and

schedule, using a delay based scheduler, the first packet for transmission based on the calculated time remaining, and transmit the first packet to the wireless device based on the schedule.

9. The system of claim 8, wherein calculating the remaining time for the first packet comprises summing the estimated delay for transmission from the access node to the wireless device and the bias factor, and subtracting the sum from the packet delay budget associated with the running application.

10. The system of claim 9, wherein scheduling, using a delay based scheduler, the first packet for transmission to the wireless devices based on the calculated time remaining further comprises:

dropping the first packet when the sum of the estimated delay for transmission from the access node to the wireless device and the bias factor is greater than the packet delay budget associated with the running application.

11. The system of claim 8, wherein the calculated bias factor is directly proportional to the number of marked packets associated with the application received within the time period.

12. The system of claim 11, wherein the calculated bias factor is reduced when a marked packet associated with the application has not been received within a threshold time.

13. The system of claim 9, wherein the processing node is further configured to:

time stamp each packet received at the access node; and

schedule, using the delay based scheduler, the first packet for transmission to the wireless device based on the time stamp for the first packet.

14. The system of claim 9, wherein the running application communicates using a real-time transport control protocol (RTCP) and a marked packet comprises an explicit congestion notification (ECN) mark.