how to amplify my sprint sierra 250u aircard signal?

i live in the woods where comcast or verizon hi speed internet isn't avaliable, so i use my 250u aircard connected to a 3g router for internet. my download speed is pretty stable, but my upload speed is up and down. if i can get a stable upload speed of over 100kp i'm fine, but sometimes its like 30,56, 21kp, when i play my xbox online if i have an upload speed over 100kp i don't have an issue, but below that my game lags so bad. how can i amplify my signal so it doesn't drop? do you think an old satelite dish in front of the aircard turned at the correct direction can amplify my signal?

Your not going to be able to amplify the signal. A dish around the card will help the receiving end but not the transmission end. A 3G connection is not meant for gaming.

The drops in signal may not have anything to do with your card but the load on the nearest cell tower.