The knowledge was looked up to encyclopedia formerly. Now the general learning is advocated where children look up to internet and think by themselves. For that purpose the stable network environment is needed where the signal speed does not reduce even if many children make access simultaneously.

There are many places like gymnasium and science room where it is dangerous for children to fall down because of cable on the floor and the cause of accident and the injury must be removed. For that purpose the safe network environment is needed where the children can move about with ease giving no heed to cable.

At K primary school 15 points of science room, personal computer room, library, music room etc. centering around teachers'room were networked in order to expand the children's action area as wide as possible and take free activity. Children and teachers are studying pleasantly everyday under the environment where they can access to the necessary information using portable personal computer at will.

Key-technology of this study environment is inexpensive Infrared Communication System.

At K primary school the perfect wireless environment was realized by connecting the schoolhouse with Infrared Communication System and attaching the additional battery to personal computer.

In the case of radio wave system the information is disturbed by the interference caused by the leakage from the neighboring room and the normal lesson is not realized. Infrared Communication System needs only a simple connection work and contributes the cost reduction.