NETWORK DESIGN SENSITIVITY STUDIES FOR USE OF DIGITAL CROSS-CONNECT SYSTEMS IN SURVIVABLE NETWORK ARCHITECTURES

This paper provides the results of an economic study on the use of SON ET Digital Cross-connect Systems (DCS's) to provide survivable transmi ssion network architectures in local exchange networks. Three fundamen tal survivable transmission technologies are considered: 1) a SONET se lf-healing ring, 2) a SONET point-to-point fiber system with 1:1 autom atic protection switching and diverse routing of protection facilities , and 3) a DCS mesh with automatic DCS restoration (rerouting) protect ion. These three technologies are used in various combinations to form six survivable network alternatives for evaluation. Two Local Exchang e Carrier (LEC) networks are used (a 15 node network and a 53 node net work) and demand, network connectivity, and unit equipment cost sensit ivities are evaluated on these alternatives. In addition, the survivab ility of each alternative in the event of a major node failure is calc ulated. The motivation for the study is to determine the viability of DCS-based survivable network architectures and, in particular, the via bility of SONET DCS's with integrated optical terminations. The study has two objectives: 1) given a specific survivable network technology, underwhat conditions is it economical to place a Broadband DCS (B-DCS ) in a central office as opposed Add-Drop Multiplexers (ADM's); and 2) which survivable technologies with B-DCS's are economical, and under what conditions. We conclude that the most cost-effective networks con sist of ''hybrids'' of SONET point-to-point, ring, and mesh technologi es, and that the B-DCS is economically viable for interconnection betw een these technologies.