Is there a way to change my NAT type to open for xbox live if I'm using a jail broken iPhone as the signal?

As in, my iPhone is putting out the wireless signal my slim is picking up. This is because it's jail broken, but the NAT type is still strict. It's notbthe treasurer signal. Is there any way to change it to open? Or simply make my wireless strength better so I can get more than 2 bars for black ops? Any answers helpful, would prefer a free and computer-free way lol