You can see those wires spanning between four towers directly around the rocket in the following screenshot (taken from this video). I assume they are some kind of antenna or for some kind of measurement. I have also seen this setup in at other rocket launches. Can anyone tell what it is there for?
These wires are part of the lightning protection. As a rocket contains flammable  components as well as sensitive electronics, it needs to be protected from lightning strikes. The main protective measure are the huge towers surrounding the rocket. If theses towers are high enough and closely located around the rocket they might provide sufficient protection. In your picture an additional grid of wires is used to better shield the central part of the start complex.
To determine whether protection is sufficient, one uses a geometry based method: If a ball of a given size (blue, typically 20 to 60 meter radius, depending on how much protection is needed) can not reach the object, then it is safe. In the drawing, the two black masts are sufficient to protect the green rocket but not tall enough to protect the red one. In the later case the towers need to be taller, closer together or an additional mesh is needed. Note that protection from sideways is not needed as much as protection from top.