ENERGY EFFICIENCY WITH RATE ADAPTATION

• US 20110149990A1
• Filed: 12/18/2009
• Published: 06/23/2011
• Est. Priority Date: 12/18/2009
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Alcatel-Lucent USA, Inc. (Nokia Corporation)
• Inventors: Francini, Andrea, Stiliadis, Dimitrios
• Granted Patent: US 8,493,856 B2
• Time in Patent Office: Days
• US Class Current: 370/419
• CPC Class Codes: H04L 47/2425 for supporting services specification, e.g. SLA
• CPC Class Codes: H04L 47/28 in relation to timing considerations
• CPC Class Codes: H04L 47/564 Attaching a deadline to packets, e.g. earliest due date first

Abstract

A system and method of rate adaptation is disclosed for energy efficiency. The system and method of rate adaptation for energy efficiency provides for parsing a heterogeneous network into rate-adaptation domains that are fully isolated with respect to the control of their operating states. The system and method is particularly useful for creating the conditions for the incremental introduction of rate-adaptive devices in existing networks; combining the best properties of sleep-state exploitation and rate scaling techniques by defining a class of state-setting policies for rate adaptation schemes that enforce tight deterministic bounds on the extra delay that the schemes may cause to network traffic at every node where they are deployed.

Claims

1. A method of establishing a rate-adaptation domain in a packet network having a plurality of domains, said method comprising the steps of:

receiving packets at an input interface from a domain immediately upstream to said rate-adaptation domain;

establishing Quality-of-Service requirements associated with said received packets;

processing said received packets in a processing unit;

dispatching packets at an output interface to a domain immediately downstream from said rate-adaptation domain;

establishing a set of state variables;

controlling the operating state of said processing unit with said state variables so as to control the rate at which packets are dispatched over said output interface;

selecting such state variables so as to satisfy a feasible departure curve; and

further selecting such state variables so as to reduce energy consumption in said rate-adaptation domain.

2. A method as claimed in claim 1 wherein

said Quality-of-Service requirements comprise a maximum added delay.

3. A method as claimed in claim 1 wherein

said further selecting step selects state variables so as to place said processing unit in a sleep state.

4. A method as claimed in claim 1 wherein

said further selecting step selects state variables so as to adjust the clock rate of said processing unit.

5. A method as claimed in claim 1 wherein

said selecting step uses a state setting policy to select said state variables.

6. A method as claimed in claim 5 wherein

said state setting policy is based upon system parameters of said rate-adaptation domain.

7. A method as claimed in claim 6 wherein

said system parameters of said rate-adaptation domain comprise at least one of the group of a power-rate function, a state transition time, and a minimum state hold time.

8. A method as claimed in claim 1 wherein

said packet processing step comprises at least one of the group of parsing, modifying, and storing in a buffer queue.

9. A method as claimed in claim 8 wherein

said state variables include at least one of the group of a queue length in said buffer queue and a traffic arrival measure.

10. A method as claimed in claim 1 wherein

said feasible departure curve comprises an optimal departure curve.

11. A method of operating a packet handling device having a dynamic voltage and frequency scaling mode of operation, and a sleep exploitation mode of operation, said method comprising the steps of:

establishing a first power rate curve for said packet handling device due to sleep state exploitation mode of operation;

establishing a second power rate curve for said packet handling device due to dynamic voltage and frequency scaling mode of operation;

operating said packet handling device by selecting one of the modes of sleep state exploitation or dynamic voltage and frequency scaling so as to minimize energy consumption for a specific rate of packet processing.

12. A method as claimed in claim 11 further comprising

establishing an intersection point of said first and second power rate curves;

and

at rates below said intersection point, selecting the mode of operation which minimizes energy consumption; and

at rates above said intersection point, selecting the alternate mode of operation.

13. A method as claimed in claim 11 further comprising

establishing an intersection point of said first and second power rate curves;

and

at rates below said intersection point, selecting the sleep state exploitation mode of operation; and

at rates above said intersection point, selecting the dynamic voltage and frequency scaling mode of operation.

14. A rate-adaptation subdomain in a packet network, said packet network having a plurality of subdomains of connected network nodes, the rate-adaptation subdomain comprising:

an input interface for receiving packets from a domain immediately upstream to said rate-adaptation subdomain;

a set of Quality-of-Service requirements associated with said received packets;

a processing unit for processing said received packets;

an output interface for dispatching packets to a domain immediately downstream from said rate-adaptation subdomain;

a set of state variables for controlling the operating state of said processing unit wherein said state variables control the rate at which packets are dispatched over said output interface;

an initial subset of such state variables selected so as to satisfy a feasible departure curve; and

a further subset of said subset of state variables selected so as to reduce energy consumption in said rate-adaptation domain.

15. A rate-adaptation subdomain as claimed in claim 14 wherein

said set of Quality-of-Service requirements comprise a maximum added delay.

16. A rate-adaptation subdomain as claimed in claim 14 wherein

said further subset of state variables places said processing unit in a sleep state.

17. A rate-adaptation subdomain as claimed in claim 14 wherein

said further subset of state variables adjusts the clock rate of said processing unit.

18. A rate-adaptation subdomain as claimed in claim 14 further comprising

a state setting policy to select said initial subset of state variables.

19. A rate-adaptation subdomain as claimed in claim 18 wherein

said state setting policy is based upon system parameters of said rate-adaptation domain.

20. A rate-adaptation subdomain as claimed in claim 19 wherein

wherein said system parameters of said rate-adaptation domain comprise at least one of the group of a power-rate function, a state transition time, and a minimum state hold time.

21. A rate-adaptation subdomain as claimed in claim 14 further comprising

a buffer queue wherein said processing unit may store packets which have been at least one of the set of parsed by said processing unit and modified by said processing unit.

22. A rate-adaptation subdomain as claimed in claim 21 wherein

said state variables include at least one of the group of a queue length in said buffer queue and a traffic arrival measure.

23. A rate-adaptation subdomain as claimed in claim 14 wherein

said feasible departure curve comprises an optimal departure curve.