This paper discusses a computer-aided network planning support system called PIGEON that has been developed primarily for advancing countries implementing the applicability to various types of networks and the supportability to the sensitivity analysis. For the implementation of the applicability, the customization by reflecting existing network facilities and their accompanying restrictive conditions into a design result is focused. A case study on the customization shows the effectiveness of the reflection. The procedures are given of the sensitivity analysis in order to examine and to evaluate the effect of the uncertain factors in network planning. In particular, a method called "network modification" is proposed for the sensitivity analysis for uncertain factors associated with a partial network. The network modification efficiently integrates network planner's judgments into a design result by the interactive method. In addition, this paper describes the importance of streamlining the data input and the evaluation of design results, showing the operating time required for each work phase in network planning.

Equivalent-time sampling is a well-known technique to capture repetitive signals at finer time intervals than a sampling clock cycle time and it is widely used to implement waveform measurement with high time resolution. There are three techniques for implementing its time base (i.e., sequential sampling, random sampling and coherent sampling), and they have their respective advantages and disadvantages. In this paper we propose a new coherent sampling system which incorporates a pretrigger and time jitter reduction function for a fluctuating input signal which a random sampling system has, while maintaining the waveform recording efficiency of a conventional coherent sampling system. We also report on a technique for measuring a reference trigger time period accurately which is necessary to implement the proposed sampling system, and show its effectiveness through numerical calculations of its data recording time.