How can i reduce latency/lag when mirroring?

Im curious. All actions i do on iphone come to the tv after about 7/10th of a second. How can i reduce this?
My setup: iphone wireless to router. Router wireless to Apple TV. Apple tv to tv with normal hdmi cable. All on a 5ghz wifi on a calm channel.

Would this 7/10 of a second already become 3,5/10 of a second when i hook up the apple tv by a ethernet cable? Or is this logic flawed?

I just love mirroring games like asphalt...but the delay in steering is very annoying.

Some help would be nice... Thanks!