Shiva is the codename of the next expansion for Eve-online, its main change is the introduction of player owned structures; this means that soon you will be able to claim and defend territories. Control towers will be the means to do that, they will allow you to build many additional structures in space like hangars, defence systems (shield modules, warp distributors, missile launchers), factories and refineries, to additional modules that will allow you to expand power cores and so on. All these systems will not be placed freely but on a grid like system to both prevent possible exploits and improve the look and feel of these outposts.