Local Network Area Size Optimization

A foundation for economically optimizing the size of a local network area, defined as an area comprising a transit switch and a number of local switches homing on it, is obtained by introducing the concept of an "intra-area traffic ratio." The local network area radius is found to be optimal when the gradient of the intra-area traffic ratio relative to the area radius equals the ratio of the junction cost per kilometer to the cost per circuit for trunks going out of the area. An empirical formula for determining this intra-area traffic ratio is given.