A prototype software system that implements a methodology for the strategic planning of survivable interoffice networks is presented. The software system determines strategic locations and ring types for synchronous optical network ring placement. Two types of survivable network architectures are considered/spl mdash/1:1 diverse protection and SONET self-healing rings. The software considers three types of SONET self-healing rings/spl mdash/unidirectional, 2-fiber bidirectional, and 4-fiber bidirectional. Hubbing is assumed in all architectures. Inputs include nodes, links, connectivity, facility hierarchy, and multiyear point-to-point demands, together with the costs of fiber material and splicing, route mileage (installation), and multiplexors and regenerators of different rates. The outputs are a set of near-optimal rings based on cost, specifying the ring types and rates, fiber span sizes and counts, regenerator locations and speeds, the topology (set of links to be used), and the network cost. In addition, the software outputs the time in the planning period that each ring and fiber span should be installed.>

Robust, passive, fiber optic local communications networks have multiple paths, so that loss of a link will not preclude communications between any pairs of users. In order for such networks to support a reasonable number (10-10/sup 4/) of users, power must be distributed as evenly as possible, with as little loss as possible. Analysis according to a mathematical model for power distribution allows comparison or various circulant topologies, where circulance refers to a particular topological symmetry, and demonstrates that a high degree of connectivity aids even distribution of power. Appropriate topological design yields a network that can support thousands of users within a 50 dB loss budget, when low loss components are used.>

The power distribution of circulant topologies for passive fiber optic local communication networks (FOLCN) in the shot-noise limited case is analyzed. This class of topologies is chosen for its symmetries in both logical structure and power distribution, as well as for its mathematical tractability. Analysis according to a mathematical model for power distribution allows comparison of various circulant topologies, where circulance refers to a particular topological symmetry, and demonstrates that a high degree of connectivity aids even distribution of power. Appropriate topological design yields a network that can support thousands of users within a 50-dB loss budget, when low loss components are used.>