Congestion management and latency prediction in CSMA media

• US 9,667,547 B2
• Filed: 01/26/2015
• Issued: 05/30/2017
• Est. Priority Date: 02/01/2006
• Status: Active Grant

• Current Assignee: CoCo Communications, Corp.
• Original Assignee: CoCo Communications, Corp.
• Inventors: Edwards, Dennis, Eller, Riley, Bruestle, Jeremy, Tucker, Mark L
• Primary Examiner(s): Shingles, Kristie
• Application Number:
  US14/605,667
• Publication Number:
  US 20150142972A1
• Time in Patent Office: 855 Days
• Field of Search: 709224, 709235
• CPC Class Codes: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• CPC Class Codes: H04L 41/14 Network analysis or design
• CPC Class Codes: H04L 43/0852 Delays
• CPC Class Codes: H04L 43/10 Active monitoring, e.g. heartbeat, ping or trace-route
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/11 Identifying congestion

Abstract

A facility for congestion management and latency prediction is described. In various embodiments, the facility sums a series of fractional transmission delays wherein each fractional transmission delay is measured as a probability of a failed transmission attempt multiplied by the cost of the failed transmission attempt, and provides the sum.

Claims

1. A method that determines data-transmission congestion between a first network node and a second network node, the method comprising:

receiving, at the second network node, a series of periodic broadcast messages communicated from the first network node to the second network node,

wherein each one of the periodic broadcast messages are broadcast at a fixed interval,

wherein each one of the periodic broadcast messages comprises a bitfield that is an integer, and

wherein the integer is incremented by a value of one for each successive broadcast of each one of the periodic broadcast messages;

measuring, at the second network node, a time difference between a first one of the received periodic broadcast messages and a second one of the received periodic broadcast messages;

determining a transmission period, wherein the transmission period is the measured time difference divided by a difference between an integer of the first one of the received periodic broadcast messages and an integer of the second one of the received periodic broadcast messages;

generating, in response to receiving each new periodic broadcast message, a log of data comprising a total number of bits corresponding to a predefined number of the series of periodic broadcast messages,

wherein the log of data is an ordered series of bits ordered from a current bit associated with a current periodic broadcast message to an oldest bit associated with an oldest periodic broadcast message that corresponds to the predefined number of the series of periodic broadcast messages,

wherein a new bit associated with a newly received periodic broadcast message is added as the current bit into the log of data,

wherein the new bit is a first binary number when the transmission period associated with the newly received periodic broadcast message indicates that the newly received periodic broadcast message was received,

wherein the new bit is a second binary number when the transmission period associated with the newly received periodic broadcast message indicates that the newly received periodic broadcast message was dropped, and

wherein the oldest bit associated with the oldest periodic broadcast message is removed from the log of data when the new bit is added into the log of data.

2. The method of claim 1, wherein the first binary number is a binary “

1”

to indicate that the associated periodic broadcast message was received, and wherein the second binary number is a binary “

0”

to indicate that the associated periodic broadcast message was dropped.

3. The method of claim 1, further comprising:

dividing, in response to receiving a new periodic broadcast message, the log of data into a first log portion containing a first number of bits associated with a first number of periodic broadcast messages received during a first time period and a second log portion containing a second number of bits associated with a second number of periodic broadcast messages received during a second time period,

wherein the second time period is earlier than the first time period, and

wherein the first number of bits are associated with the first number of periodic broadcast messages, and

wherein the second number of bits are associated with the second number of periodic broadcast messages,

where the sum of the first number of bits and the second number of bits equals the total number of bits corresponding to the predefined number of the series of periodic broadcast messages represented in the log of data;

determining a first number corresponding to a number of the bits in the first log portion, wherein the number of bits in the first log portion is one of the number of bits having the first binary number or the number of bits having the second binary number;

determining a second number corresponding to a number of the bits in the second log portion, wherein the number of bits in the second log portion is the number of bits having the first binary number when the first number was based on the number of bits having the first binary number, or wherein the number of bits in the second log portion is the number of bits having the second binary number when the first number was based on the number of bits having the second binary number;

comparing the first number and the second number;

if the first number is at least equal to the second number by a predetermined criterion, continuing to generate the log of data using the total number of bits as a next periodic broadcast message is received; and

if the first number is less than the second number by the predetermined criterion, discarding the second log portion and continuing to generate the log of data using a new number of bits as the next periodic broadcast message is received, wherein the new number of bits corresponds to the first number of bits in the first log portion.

4. The method of claim 3, further comprising:

comparing the first number with the second number,

wherein the second log portion is discarded only when a difference between the first number and the second number is not statistically significant.

5. The method of claim 3, wherein the first number equals the number of the bits in the first log portion that are the first binary number, and wherein the second number equals the number of the bits in the second log portion that are the first binary number.

6. The method of claim 3, wherein the first number equals the number of the bits in the first log portion that are the second binary number, and wherein the second number equals the number of the bits in the second log portion that are the second binary number.

7. The method of claim 3,

wherein the first number is a first ratio,

wherein the second number is a second ratio,

wherein the first ratio is a ratio of a sum of the first binary numbers in the first log portion to a total number of bits in the first log portion, and

wherein the second ratio is a ratio of a sum of the first binary numbers in the second log portion to a total number of bits in the second log portion.

8. The method of claim 7, further comprising:

comparing the first ratio with the second ratio,

wherein the second log portion is discarded only when a difference between the first ratio and the second ratio is not statistically significant.

9. A method to determine data-transmission congestion between a first network node and a second network node of a network,

wherein each one of the periodic broadcast messages are broadcast at a fixed interval,

wherein each one of the periodic broadcast messages comprises a bitfield that is an integer,

wherein the integer is incremented by a value of one for each successive broadcast of each one of the periodic broadcast messages, and

wherein each one of the periodic broadcast messages communicated from the first network node and that are received by the second network node are associated with a first bit, and

wherein other periodic broadcast messages communicated from the first network node and that are dropped are associated with a second bit,

the method comprising:

measuring, at the second node, a time difference between a first one of the received periodic broadcast messages and a second one of the received periodic broadcast messages;

determining a transmission period, wherein the transmission period is the measured time difference divided by a difference between an integer of the first one of the received periodic broadcast messages and an integer of the second one of the received periodic broadcast messages;

determining that the second one of the received periodic broadcast messages is received when the transmission is less than or equal to a threshold and that the second one of the received periodic broadcast messages is dropped when the transmission is greater than the threshold;

generating, as each new periodic broadcast message is communicated, a log of data comprising a total number of bits,

wherein the total number of bits in the log of data corresponds to a predefined total number of monitored periodic broadcast messages,

wherein the log of data is an ordered series of the first bits and the second bits ordered from a current bit associated with a current periodic broadcast message to an oldest bit associated with an oldest periodic broadcast message,

wherein the bit associated with the newly received periodic broadcast message is added as the current bit into the log of data, and wherein a bit associated with the oldest periodic broadcast message is removed from the log of data;

dividing, as each new periodic broadcast message is communicated, the log of data into a first log portion containing the first bits and the second bits associated with periodic broadcast messages communicated during a first time period and a second log portion containing the first bits and the second bits associated with periodic broadcast messages communicated during a second time period, wherein the second time period is earlier than the first time period;

determining, as each new periodic broadcast message is communicated, a first number corresponding to a number of the first bits in the first log portion, wherein the number of bits in the first log portion is one of the number of bits having the first binary number or the number of bits having the second binary number;

determining, as each new periodic broadcast message is communicated, a second number corresponding to a number of the first bits in the second log portion, wherein the number of bits in the second log portion is the number of bits having the first binary number when the first number was based on the number of bits having the first binary number, or wherein the number of bits in the second log portion is the number of bits having the second binary number when the first number was based on the number of bits having the second binary number;

comparing, as each new periodic broadcast message is communicated, the first number and the second number;

if the first number is at least equal to the second number by a predetermined criterion, continuing to generate the log of data using the total number of bits; and

if the first number is less than the second number by the predetermined criterion, discarding the second log portion and continuing to generate the log of data using a new number of bits as a next message is provided, wherein the new number of bits corresponds to the number of the first bits and the second bits in the first log portion.

10. The method of claim 9, wherein further comprising:

monitoring the next periodic broadcast message communicated from the first network node to the second network node, wherein one of the first bit and the second bit is generated based on whether the next periodic broadcast message is received or dropped, and wherein the generated bit is added as the current bit of the log of data.

11. The method of claim 9,

wherein the first number is a first ratio,

wherein the second number is a second ratio,

wherein the first ratio is a ratio of a sum of the first binary numbers in the first log portion to a total number of bits in the first log portion, and

wherein the second ratio is a ratio of a sum of the first binary numbers in the second log portion to a total number of bits in the second log portion.

12. The method of claim 10, further comprising:

comparing the first ratio with the second ratio,

wherein the second log portion is discarded only when a difference between the first ratio and the second ratio is not statistically significant.

13. The method of claim 9, wherein each first bit is one of a first binary number that indicates that the message was received and each second bit is a second binary number that indicates that the message was dropped.

14. The method of claim 9, wherein the first number equals the number of the first bits in the first log portion, and wherein the second number equals the number of the first bits in the second log portion.

15. The method of claim 9, wherein the first number equals a number of the second bits in the first log portion, and wherein the second number equals a number of the second bits in the second log portion.