Can the iPhone 4s connect to a 4g network?

I currently have sprint. My 3G network isnt bad but it isn't great. I'm wondering will Sprint make its network any faster sometime soon?

Are they even trying?

Sometime in the future will my 4s be able to connect to a 4G network?

No it can't because the iPhone 4S does not support 4G LTE networks. But still the peak speed of 3G is still high and many operators are yet to use its full potential.

No. Your phone can't be upgraded to a 4g network. It's built for 3g or Edge only. You'll have to upgrade to the iPhone 5.