Sonic repulsion field

Sonic repulsion field was a type of defensive technology used by the Global Defense Initiative during the Third Tiberium War.

Background
An application of harmonic resonance technology, sonic repulsion fields were sonic barriers projected from multiple stationary hubs. Originally used to contain Tiberium fields in Blue zone cities such as London and Munich, they were later repurposed to protect vital military structures from enemy sabotage.

Game unit
Structures protected by sonic repulsion fields cannot be captured by engineers or demolished by GDI and Nod commandos, though they also cannot be repaired by friendly engineers. Protected structures become much more resistant to damage. The sonic repulsion field will be destroyed if the structure it protects is critically damaged.

This power cannot be used on power plants and support structures other than the ion cannon control. It also cannot be used on the structures of other factions.

Behind the scenes

 * Sonic repulsion fields originally appeared in Tiberium Wars as unbuildable structures that contained Tiberium fields in certain Blue zone maps, they were simply known as "Wall Hubs".