The customer of this example considers the high speed communication system between town office and public hall, or town office and library/history museum. But there is a railway between them seriously.

□	It is much difficult to construct the private communication line under the railway.  And it is much expensive.
□	How about the cable laid with poles? How about the cable laid along railway?  But It takes long time until the completion of license in both cases and it is anxious about the safety.
□	Radio wave is simply constructed and the microwave is one of the good selection of methods. But a full-time technician is needed and the security is difficult to be maintained because of signal leakage.

Then Infrared Communication was considered for the solution.

The keyword of the introduction was as follows.

• Cost performance : High running cost is not needed after the introduction.
• High security : It is free from signal leakage and tapping.
• 100Mbps high speed network : Communication speed maintains if plural PC are used.
• Communication distance of 300m : The distance was 240m between town office and other buildings.

At first the weather and the distance were the cause of anxiety, but there was no problem. Infrared communication system is now operating smoothly even in the case of plural access.