Nobuyuki Fujikura

Development and performance evaluation of point to multipoint communication control scheme via satellite

In this paper, a new point to multipoint communication control scheme via satellite characterized by cyclic turn response control based on a receiving station grouping concept is described. Then data transfer experiments are performed to compare the cyclic turn response control scheme (referred to as the proposed response scheme) with the conventional sequential response and simultaneous response schemes, which results in revealing that the proposed response scheme is the most efficient. Furthermore, through considerations of an analytical equation of transmission time, it is qualitatively shown that the proposed response scheme becomes even more effective when the number of receiving stations becomes larger.

Sensitivity analysis of optimal message sizes for file transfer via satellite and terrestrial links

A description is given of experiments on file transfer via satellite and terrestrial links. These results are then analyzed quantitatively. A model and an estimation method for measuring a file transmission time are developed, so that optimal message sizes under various file transfer conditions can be calculated and shown. These make it possible to select optimal message sizes and optimal communication links which provide the shortest transmission time for different file transfer conditions.<<ETX>>