Portal array seems to be a mechanism that can transport objects from one point to another faster than light. It may be some type of wormhole generator. It is known to be powered by uranium, and blocked through strong magnetic fields. This was the reason why the Inostranka prisoners were unable to be simply transported out-they were too close to the North Pole (Face Off). Thomas used this technology first to transport the airliner that was to be crashed into President Martinez into the Arizona desert, and then intended for it to transport thousands more of his people to Earth. In the end, it transports their entire planet into orbit around Earth (Arrival).