# US 5,216,591 A · Method for efficient distributed data communications network backbone node location > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,216,591 A - Document ID: US5216591A - Status: Granted - Kind: A - Application number: 07/475,887 - Filed: 1990-02-06 - Granted: 1993-06-01 - Earliest claimed: 1990-02-06 - Assignees: Sprint International Communications Corp. - Inventors: Paul Nemirovsky; Michael Ball; Roy Dahl - Web page: https://patentgrep.com/patent/US5216591A ## CPC - H04Q 3/66: Traffic distributors - G06Q 10/06316: {Sequencing of tasks or work} - H04L 41/16: using machine learning or artificial intelligence - H04Q 3/0083: {Network planning or design; Modelling of planned or existing networks} - H04Q 2213/13524: cost management - H04Q 2213/13535: distributed systems - also domains in service creation - H04Q 2213/13543: network planning, configuration management, e.g. for growth - Y10S 706/909: Communication - H04Q: SELECTING (switches, relays, selectors H01H; wireless communication networks H04W) - G06Q: INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract A method for selecting the most cost-efficient locations for backbone nodes in a distributed data network is disclosed. The method iteratively evaluates candidate backbone node locations, adding in each iteration the candidate whose addition to the network would create the greatest savings in total network cost. After all candidates which produce savings are added to the network, the method iteratively evaluates the backbone node locations and removes those whose removal would create cost savings. Data terminals are reassigned among the backbone nodes in the least cost manner. The method also estimates total network cost based on the resulting network configuration. ## Claims ### Claim 1 A method for constructing a data communication network having; i) a local access network including a plurality of terminals; and ii) a backbone including backbone nodes for routing data traffic within the backbone and a plurality of first links connecting the backbone nodes, said method comprising steps of: (a) selecting mandatory backbone nodes related to various ones of said plurality of terminals; (b) selecting a new candidate backbone node for addition to the backbone; (c) evaluating the effect on the network of adding the new candidate backbone node to the backbone; (d) if the evaluation of step (c) indicates that effect on the network is positive, adding the new candidate backbone node to the backbone; (e) evaluating the effect of removing a backbone node from the backbone; (f) if evaluation of step (e) indicates that the effect on the network is positive, removing the backbone node from the backbone; and (g) reassigning terminals to backbone nodes included in the backbone to provide the lowest cost system to transmit data between said terminals. ### Claim 2 (depends on 1) The method for constructing a data communication network according to claim 1 further comprising repeating the steps (a) through (g) and selecting the lowest cost system to transmit data between said terminals. ### Claim 3 (depends on 1) The method for constructing a data communication network according to claim 1 wherein said backbone nodes include data switches. ### Claim 4 (depends on 1) The method for constructing a data communication network according to claim 1 wherein said first links are high volume data lines. ### Claim 5 (depends on 4) The method for constructing a data communication network according to claim 4 wherein said high volume data lines are fiber optic lines. ### Claim 6 (depends on 1) The method for constructing a data communication network according to claim 1 wherein said step of selecting a new candidate node includes substeps of: (i) measuring cost savings of the local access network; (ii) offsetting said measured savings by any increase in the cost of the backbone attributed to adding a new backbone node and adding a switch associated with the new backbone node; and (iii) evaluating cost savings of the network. ### Claim 7 (depends on 6) The method for constructing a data communication network according to claim 6 wherein the savings in local access network costs includes the savings associated with reassigning terminals to the candidate node. ### Claim 8 A computer system for constructing a data communication network having; i) a local access network including a plurality of terminals; and ii) a backbone including backbone nodes for routing data traffic within the backbone and a plurality of first links connecting the backbone nodes, said computer system comprising: (a) means for selecting mandatory backbone nodes related to various ones of said plurality terminals; (b) means for selecting a new candidate backbone node for addition to the backbone; (c) means for evaluating the effect on the network of adding the new candidate backbone node to the backbone; (d) means for adding the new candidate backbone node if said means for evaluating determines that the effect on the network is positive; (e) second means for evaluating the effect of removing a backbone node from the backbone; (f) means for removing the backbone node if said second means for evaluating determines that the effect on the network is positive; and (g) means for reassigning terminals to backbone nodes to the backbone to provide the lowest cost system to transmit data between said terminals. ### Claim 9 (depends on 8) The computer system for constructing a data communication network according to claim 8 wherein said backbone modes include data switches. ### Claim 10 (depends on 8) The computer system for constructing a data communication network according to claim 8 wherein said first links are high volume data lines. ### Claim 11 (depends on 10) The computer system for constructing a data communication network according to claim 10 wherein said high volume data lines are fiber optic lines.