said by newbiewisp :

my dillema is not the school..I'm trying to come up with a solution that enables me to send signals over the
top of a small hill, and down the other side.Repeaters cut the signal strength in half and im afraid that the consumer grade repeaters are not strong enough even with a 15 dBi omni antenna.The distance between my ap to the hill is about 2km and from the hill to school is about 2-3km.Is there a repeater that would do this task using only an omni antenna???im kinda repeating myself,i'm not too familiar with repeaters...thank you again.