Communication delay

Yesterday we experienced that our communication is indeed working, but it is not yet suitable for our mars rover.
There is a huge delay between the moment one brick finds an edge and the moment the other brick reacts (stops). The delay can be seen in this video. The moment someone puts his hand just below the light sensor the right brick detects that all sensors are above land and sends a signal "clear to drive" to the left brick. This brick will then start driving.

We have a few options to test left. Hopefully we'll find a way to reduce the time delay soon.