Border protection grid
From Memory Alpha, the free Star Trek reference
New timeline
(split 2233)
(split 2233)
A Border Protection Grid was a system used in an alternate 2258 to protect some planets of the United Federation of Planets. Earth was protected by such a system. They could be bypassed if an attacker knew their subspace frequencies, information to which Starfleet captains were privy.
In an alternate timeline's 2258, Nero used an Centaurian slug to extract the frequencies of the Earth grid from Christopher Pike. (Star Trek)
