System and method for ranking content popularity in a content-centric network

1. A computer-executable method for ranking content popularity in a content-centric network (CCN) content cache, the method comprising:

receiving, by a CCN node, an interest in a piece of content stored in the content cache;

servicing the interest by accessing the piece of content;

in response to the piece of content being accessed, updating an object-specific service rate associated with the piece of content by calculating an exponentially weighted moving average (EWMA) of numbers of accesses to the piece of content over a time constant, wherein calculating the EWMA involves applying a weight coefficient that is a function of a time interval between consecutive accesses to the content piece and performing a table lookup to obtain pre-calculated exponential weight functions, and wherein the object-specific service rate indicates a frequency that the piece of content is accessed;

updating system-wide service rate statistics, which involves calculating a per-object service rate averaged over a set of pieces of content stored in the content cache; and

determining a popularity level associated with the piece of content based on the updated object-specific service rate and the updated system-wide service rate statistics.

2. The method of claim 1 , wherein updating the system-wide service rate statistics involves calculating a mean and a variance of the system-wide, per-object service rate.

3. The method of claim 2 , further comprising pre-calculating a popularity threshold based on:

the system-wide, per-object service rate being a random variable with a normal distribution; and

the mean and the variance of the system-wide, per-object service rate.

4. The method of claim 3 , wherein determining the popularity level involves labeling the piece of content object as popular in response to the object-specific service rate associated with the piece of content equal to or greater than the pre-calculated popularity threshold.

5. The method of claim 1 , wherein calculations associated with updating the object-specific service rate, updating the system-wide service rate statistics, and determining the popularity level are performed by a fixed-point processing unit.

6. An system for ranking content popularity in a content-centric network (CCN) content cache, the system comprising:

a processor; and

a storage device coupled to the processor and storing instructions which when executed by the processor cause the processor to perform a method, the method comprising:

receiving, by a CCN node, an interest in a piece of content stored in the content cache;

servicing the interest by accessing the piece of content;

in response to the piece of content being accessed, updating an object-specific service rate associated with the piece of content by calculating an exponentially weighted moving average (EWMA) of numbers of accesses to the piece of content over a time constant, wherein calculating the EWMA involves applying a weight coefficient that is a function of a time interval between consecutive accesses to the content piece and performing a table lookup to obtain pre-calculated exponential weight functions, and wherein the object-specific service rate indicates a frequency that the piece of content is accessed;

updating system-wide service rate statistics, which involves calculating a per-object service rate averaged over a set of pieces of content stored in the content cache; and

determining a popularity level associated with the piece of content based on the updated object-specific service rate and the updated system-wide service rate statistics.

7. The system of claim 6 , wherein updating the system-wide service rate statistics involves calculating a mean and a variance of the system-wide, per-object service rate.

8. The system of claim 7 , wherein the method further comprises pre-calculating a popularity threshold based on:

the system-wide, per-object service rate being a random variable with a normal distribution; and

the mean and the variance of the system-wide, per-object service rate.

9. The system of claim 8 , wherein determining the popularity level involves labeling the piece of content object as popular in response to the object-specific service rate associated with the piece of content equal to or greater than the pre-calculated popularity threshold.

10. The system of claim 6 , wherein calculations associated with updating the object-specific service rate, updating the system-wide service rate statistics, and determining the popularity level are performed by a fixed-point processing unit.

11. A non-transitory computer-readable storage medium storing instructions that when executed by a computer cause the computer to perform a method for ranking content popularity in a content-centric network (CCN) content cache, the method comprising:

receiving, by a CCN node, an interest in a piece of content stored in the content cache;

servicing the interest by accessing the piece of content;

in response to the piece of content being accessed, updating an object-specific service rate associated with the piece of content by calculating an exponentially weighted moving average (EWMA) of numbers of accesses to the piece of content over a time constant, wherein calculating the EWMA involves applying a weight coefficient that is a function of a time interval between consecutive accesses to the content piece and performing a table lookup to obtain pre-calculated exponential weight functions, and wherein the object-specific service rate indicates a frequency that the piece of content is accessed;

updating system-wide service rate statistics, which involves calculating a per-object service rate averaged over a set of pieces of content stored in the content cache; and

determining a popularity level associated with the piece of content based on the updated object-specific service rate and the updated system-wide service rate statistics.

12. The computer-readable storage medium of claim 11 , wherein updating the system-wide service rate statistics involves calculating the mean and a variance of a system-wide, per-object service rate.

13. The computer-readable storage medium of claim 12 , wherein the method further comprises pre-calculating a popularity threshold based on:

the system-wide, per-object service rate being a random variable with a normal distribution; and

the mean and the variance of the system-wide, per-object service rate.

14. The computer-readable storage medium of claim 13 , wherein determining the popularity level involves labeling the piece of content object as popular in response to the object-specific service rate associated with the piece of content equal to or greater than the pre-calculated popularity threshold.

15. The computer-readable storage medium of claim 11 , wherein calculations associated with updating the object-specific service rate, updating the system-wide service rate statistics, and determining the popularity level are performed by a fixed-point processing unit.