[Wireless] [Airimba] Why does it suck?

I can't play Tribes on my wireless connection without lag spiking every few seconds. Is there any way I can change this or is it just because the wireless network is busy atm?

My connection is through Airimba Wireless. It's some wireless internet my apartments can get to avoid the trouble of installation of Charter Cable or some other cable internet..

Anything I can do?