Practical constraints in growth of lightwave networks

The amount of fiber required, propagation delay, and length of the longest link are significant design constraints in spatially large networks. This paper examines these characteristics from the viewpoint of growth and compares basic networks with hierarchical ones in terms of these characteristics. Results show that, when considering growth from three nodes, a star network randomly placed with a uniform distribution uses less fiber than a dual ring until there are 57 nodes. As the networks become large, the star has the smallest propagation delay and the dual ring uses the least amount of fiber. A two-level network having a star on the upper level and dual rings on the lower network level performs well in both categories by using 1.38 times as much fiber as the dual ring and having 1.65 times the propagation delay of a star as the number of nodes becomes large.