ibook wireless connection problems - no base station showing?

[thespine]

I have an ibook G4, 30 gb hd, 512 ram, system 10.4.9, bought used about 6 months ago. Up until a week or so ago, it has been running just fine. Now, my internet connection is considerably slower and when I am farther away, upstairs, it sometimes drops and doesn't recognize my network until I turn airport off and on a few times. My daughter also has an ibook connected to this network and hers is also running a lot slower,especially upstairs so I would kinda think that it isn't my computer. I am using a Belkin. One thing that I noticed is that when I open airport admin utility, there is nothing there. It does not show an airport base station. I am very new at wireless and really have no idea of what to even try to figure this out. But I did do some research and there was reference to making some changes to the base station to improve performance but I can't find a base station. Did I set this up wrong in the beginning? I really am clueless as to where to start to figure out why it is running so much slower. Any help would be appreciated.