Window size determination using fuzzy logic

• US 5,905,978 A
• Filed: 07/15/1996
• Issued: 05/18/1999
• Est. Priority Date: 07/15/1996
• Status: Expired due to Term

• Current Assignee: Unisys Corporation
• Original Assignee: Unisys Corporation
• Inventors: O'Brien, Gerard, Smith, John H.
• Primary Examiner(s): Downs, Robert W.
• Assistant Examiner(s): Shah, Sanjiv
• Application Number:
  US08/680,757
• Time in Patent Office: 1,037 Days
• Field of Search: 395/61, 395/200.65, 370/232, 370/233, 370/231, 370/230, 370/389, 706/52, 706/8, 706/1, 707/201
• US Class Current: 706/52
• CPC Class Codes: G06F 2205/126 Monitoring of intermediate fill level, i.e. with additional means for monitoring the fill level, e.g. half full flag, almost empty flag
• CPC Class Codes: G06F 5/06 for changing the speed of data flow, i.e. speed regularising or timing, e.g. delay lines, FIFO buffers; over- or underrun control therefor G06F7/78 takes precedence
• CPC Class Codes: G06F 5/12 Means for monitoring the fill level; Means for resolving contention, i.e. conflicts between simultaneous enqueue and dequeue operations
• CPC Class Codes: H04L 47/10 Flow control; Congestion control

Abstract

A memory utilization value indicative of memory utilization associated with a data channel is received. A queue depth value indicative of the queue depth of messages located within a message queue maintained by the data channel is also received. A fuzzy logic design is executed with the memory utilization value in the queue depth value used as input parameters. A crisp value is then generated which corresponds to a window size of the data channel.

Claims

1. Apparatus for characterizing window size of a data channel, comprising:

means for receiving an indication of memory utilization associated with said data channel;

means for receiving a queue depth value indicative of queue depth of messages located within a message queue maintained by said data channel; and

fuzzy logic generating means for using said memory utilization indication and said queue depth value to generate a crisp value corresponding to said window size.

2. Apparatus as set forth in claim 1 which further includes:

a first fuzzy logic input set including a first plurality of membership functions corresponding to queue depth of a message queue associated with said data channel;

a second fuzzy logic input set including a second plurality of membership functions corresponding to memory utilization of a memory associated with said data channel;

a fuzzy logic output set including a third plurality of membership functions corresponding to window size; and

a plurality of fuzzy logic rule statements defining the relationships between a) said first fuzzy logic input set and said second fuzzy logic input set, and b) said fuzzy logic output set.

3. Apparatus as set forth in claim 1 which further includes:

data channel means for generating an indication of said memory utilization associated with said data channel.

4. Apparatus as set forth in claim 3 which further includes:

processor means for transmitting messages to said data channel and wherein at least one of said queue depth value and said memory utilization value is transmitted from said data channel to said processor to acknowledge each message transmission.

5. Apparatus as set forth in claim 1 which further includes means for incrementing said queue depth value each time one of said messages is added to said queue and decremented the value each time one of said messages is removed from said queue.

6. Apparatus as set forth in claim 1 wherein said memory utilization indication value comprises a smoothed percentage of memory used over a period of time.

7. Apparatus as set forth in claim 6 which further includes:

a message queue for maintaining a queue of messages which are waiting to be serviced by a network.

8. Apparatus as set forth in claim 1 wherein said fuzzy logic generating means comprises:

means for generating a first fuzzy input set including a first plurality of membership functions corresponding to queue depth;

means for generating a second fuzzy input set including a second plurality of membership functions corresponding to memory utilization;

means for generating a fuzzy output set including a third plurality of membership functions corresponding to window size; and

means for generating a plurality of logic rule statements defining relationships between a) said first fuzzy input set and said second fuzzy input set and b) said fuzzy output set.

9. Apparatus as set forth in claim 1 wherein said crisp value comprises one of a plurality of output sets, each output set corresponding to a respectively different window size.

10. Apparatus for characterizing window size as set forth in claim 1 which further includes:

means for receiving a plurality of data values representative of the operation of said data channel; and

means for processing said plurality of data values using fuzzy logic design to generate said crisp value corresponding to said window size.

11. Apparatus as set forth in claim 1 which further includes:

means for regulating flow control between a processor and a data channel;

said means for executing a fuzzy logic design to generate a crisp value corresponding to window size of said data channel further including;

means for varying flow control between said processor and said data channel depending upon said generated crisp value.

12. Apparatus for regulating flow control between a processor and a data channel, comprising:

means for receiving an indication of memory utilization associated with said data channel;

means for receiving a queue depth value indicative of queue depth of messages located within a message queue maintained by said data channel; and

calculating means for using said memory utilization indication and said queue depth value to generate a window size value corresponding to said window size.

13. Apparatus as set forth in claim 12 which further includes:

means for generating a crisp value corresponding to window size of said data channel using a fuzzy logic design; and

means for varying flow control between said processor and said data channel based upon said generated crisp value.

14. Apparatus according to claim 12, wherein said calculating means includes a fuzzy logic design for processing said memory utilization indication and said queue depth value to generate a crisp value corresponding to said window size.

15. A method for varying data channel window size to establish efficient use of a data channel, comprising the step of:

connecting a computer system to a network

transferring data as packaged messages to and from said computer system and to and from said network through an input/output channel board having a buffer memory to hold said messages before being transmitted over said network,

storing said packaged messages in said buffer memory in a message queue,

determining a queue depth value indicative of the queue depth of messages loaded into said message queue,

determining a buffer memory utilization value predication on the maximum queue depth and the numbers of said messages in said message queue,

generating a first fuzzy logic input set corresponding to said queue depth value,

generating a second from logic input set corresponding to said memory utilization value,

generating a plurality of logic rule statements defining desired relationships between said first and said second fuzzy input sets,

executing a fuzzy logic design corresponding to fuzzy logic input sets, and

generating a crisp value corresponding to a desired window size for utilization by said computer system.

16. A method of varying data channel window size according to claim 15, wherein said memory utilization value is generated by said data channel.

17. A method of varying data channel window size according to claim 15, wherein said queue depth value is incremented each time one of said messages is added to said queue and decremented each time one of said messages is removed from said queue.