Network construction in my customer's company.
I have designed network of this buildings which is located in very very countryside. But this network is an optical network.
Backbone switch's speed is 10 Gbps.
We can build an optical network anywhere you are.
Our Network skill is the best of the world.
I think that it is an arts.

By "Our Network skill is the best of the world", I assume you mean Korea? Really? I noticed that you are using 3Com (American) switches. By they way, use Cisco. They have a much better IOS. Also, you're running Cat 5 (copper) instead of fiber to the workstations. In the States we use Fiber to the workstations on almost all commerical networks. You're behind the times.

I think that End User's PCs need not use a fiber cable.
End User's speed is 100Mbps and it is enough.
But We have using all fiber interfaces of Core Area such like Backbone Switches, Server farms. And this Network is not commercial network.
So, I have to think its Cost.
I need to design with the smallest cost and then, I need to get the largest effect. That is very hard question.
That is not simple as your idea. My customer has not a lot of money like you.
So, I have to find some good solution for my customer.
It is not easy like your idea.
Yes, CISCO is very good but their products are too expensive.
Can you understand what I say ?
You know, I am Cisco engineer.
But, we are not suggest only CISCO.
Hey, friend ! Do you know what the best important is ?
It is not your idea and my idea, it is just a COST.
Do you know that ?
Network Design is not simple as your idea.