Optimum design of alternative routing systems with partial overflow scheme

Abstract

AbstractAn optimum design of alternative routing systems using the equivalent random method was proposed by Akimaru et al. However, it has a problem in that an individual call loss differs depending on call types, because of the design which places the average call loss rate of the alternative route within a predetermined value. In the present paper, we propose alternative routing systems with partial overflow scheme as a method to control the individual call losses. We describe the optimum design which minimizes the system cost under a given point‐to‐point call loss rate between origin and destination, and apply GI approximation, which we proposed before, to evaluate the individual call losses. The design method is described on a basic triangle alternative routing model, and the approximation is compared with an exact solution via numerical examples. It is shown that the design method has sufficient accuracy in less computational time compared with the exact solution. Further, it is clarified that the method prevents excessive investment with reasonable service and that a significant saving in system cost is attained compared with the conventional alternative routing system.