Fuzzy logic-based evidence fusion tool for network analysis

• US 5,787,235 A
• Filed: 05/09/1995
• Issued: 07/28/1998
• Est. Priority Date: 05/09/1995
• Status: Expired due to Fees

• Current Assignee: General Dynamics Government Systems Corporation (General Dynamics Corporation)
• Original Assignee: GTE Government Systems Corporation (General Dynamics Corporation)
• Inventors: Smith, Michael D., Bonde, Allen R. Jr., Napolitano, Rosemarie, Wolfe, Diane M., Catherine, Gregory J.
• Primary Examiner(s): Downs, Robert W.
• Assistant Examiner(s): Rhodes, Jason W.
• Application Number:
  US08/437,732
• Time in Patent Office: 1,176 Days
• Field of Search: 395/50, 395/61, 395/900, 395/3, 395/54
• US Class Current: 706/47
• CPC Class Codes: H04Q 2213/1305 Software aspects
• CPC Class Codes: H04Q 2213/13103 Memory
• CPC Class Codes: H04Q 2213/13343 Neural networks
• CPC Class Codes: H04Q 2213/13349 Network management
• CPC Class Codes: H04Q 3/0083 Network planning or design; Modelling of planned or existing networks

Abstract

A fuzzy-logic-based evidence fusion tool for predicting function levels of a switch in a telecommunications network. Confidence factors related to the geographical location and to the physical characteristics of the switch are acquired and mapped into fuzzy membership values. The membership values activate a set of fuzzy evidence fusion rules at each function level, and a degree of truth for each rule is inferred. A defuzzification scheme combines the degree of truth of each rule into a single combined confidence factor for each function level. Finally, the maximum combined confidence factor for each rule is determined, and the switch function level corresponding to that confidence factor is assigned to the switch.

Claims

1. Apparatus for determining which function level that a switch is likely functioning at in a telecommunication system wherein said switch can be functioning at any one in a set of n function levels, said switch having geographic characteristics and physical characteristics, said apparatus comprising:

an expert system for providing a first set of n confidence factors for the switch, each confidence factor, CFgeo, representing the confidence that the switch is functioning at a corresponding function level based upon the geographic characteristics of the switch and for providing a second set of n confidence factors for the switch, each confidence factor, CFphy, representing the confidence that the switch is functioning at a corresponding level based upon the physical characteristics of the switch;

fuzzy mapping means for fuzzy mapping the confidence factor CFgeo for the switch into high, medium and low fuzzy membership values for CFgeo at each function level;

fuzzy mapping means for fuzzy mapping the confidence factor CFphy for the switch into high, medium and low fuzzy membership values for CFphy at each function level;

a set of fuzzy evidence fusion rules coupled to the fuzzy mapping means, each rule activated by the fuzzy membership values for CFgeo and CFphy at each function level for inferring a degree of truth for each rule for each function level;

a singleton defuzzification means for combining the degree of truth of each rule into a single combined confidence factor CF for each function level; and

means for determining the maximum combined confidence factor and assigning to the switch the function level corresponding to the maximum confidence factor.

2. Apparatus for determining which function level that a switch is likely functioning at in a telecommunication system wherein the switch can be functioning at any one function level in a set of n function levels, the switch having geographic characteristics and a first set of n confidence factors for the switch, each confidence factor, CFgeo, representing the confidence that the switch is functioning at a corresponding function level based upon the geographic characteristics of the switch and physical characteristics, a second set of n confidence factors for the switch, each confidence factor, CFphy, representing the confidence that the switch is functioning at a corresponding level based upon the physical characteristics of the switch, the apparatus comprising:

fuzzy mapping means for fuzzy mapping the confidence factor CFgeo for the switch into high, medium and low fuzzy membership values for CFgeo at each function level;

fuzzy mapping means for fuzzy mapping the confidence factor CFphy for the switch into high, medium and low fuzzy membership values for CFphy at each function level;

a set of fuzzy evidence fusion rules coupled to the fuzzy mapping means, each rule activated by the fuzzy membership values for CFgeo and CFphy at each function level for inferring a degree of truth for each rule for each function level;

a singleton defuzzification means for combining the degree of truth of each rule into a single combined confidence factor CF for each function level; and

means for determining the maximum combined confidence factor and assigning to the switch the function level corresponding to the maximum confidence factor.

3. A computer method for determining which function level that a switch is likely functioning at in a telecommunication system wherein the switch can be functioning at any one function level in a set of n function levels, the switch having geographic characteristics and physical characteristics, comprising the steps:

providing a first set of n confidence factors for the switch, each confidence level, CFgeo, representing the confidence that the switch is functioning at a corresponding function level based upon the geographic characteristics of the switch;

providing a second set of n confidence factors for the switch, each confidence level, CFphy, representing the confidence that the switch is functioning at a corresponding level based upon the physical characteristics of the switch;

fuzzy mapping the confidence factor CFgeo for the switch into high, medium and low fuzzy membership values for CFgeo at each function level;

fuzzy mapping the confidence factor CFphy for the switch into high, medium and low fuzzy membership values for CFphy at each function level;

providing a set of fuzzy evidence fusion rules, each rule activated by the fuzzy membership values for CFgeo and CFphy at each function level;

inferring a degree of truth for each rule for each function level;

combining the degree of truth of each rule into a single combined confidence factor CF for each function level; and

determining the maximum combined confidence factor and assigning to the switch the function level corresponding to the maximum confidence factor.

4. Apparatus for determining which function level that a switch is likely functioning at in a telecommunication system wherein the switch can be functioning at any one function level in a set of n function levels, the switch having geographic characteristics and physical characteristics, comprising:

a data base including a first set of n confidence factors for the switch, each confidence level, CFgeo, representing the confidence that the switch is functioning at a corresponding function level based upon the geographic characteristics of the switch and a second set of n confidence factors for the switch, each confidence level, CFphy, representing the confidence that the switch is functioning at a corresponding level based upon the physical characteristics of the switch;

a programmable computer arranged to access the data base; and

software adapted to program the computer to;

a) fuzzy map the confidence factor CFgeo for the switch into high, medium and low fuzzy membership values for CFgeo at each function level;

b) fuzzy map the confidence factor CFphy for the switch into high, medium and low fuzzy membership values for CFphy at each function level;

c) apply a set of fuzzy evidence fusion rules, each rule activated by the fuzzy membership values for CFgeo and CFphy at each function level;

d) infer a degree of truth for each rule for each function level;

e) combine the degree of truth of each rule into a single combined confidence factor CF for each function level; and

f) determine the maximum combined confidence factor and assign to the switch the function level corresponding to the maximum confidence factor.