Transwarp conduit

From Memory Alpha, the free Star Trek reference.

A transwarp conduit opens

The rogue Borg ship enters a transwarp conduit

A transwarp conduit is a form of faster-than-light travel, an artificial construct similar to a wormhole. Vessels traveling in such conduits can traverse extensive distances in a few hours. The Borg used this technology extensively.

The opening of a Borg transwarp conduit is characterized by triquantum waves, subspace disruptions with a field magnitude exceeding 2.9 teracochranes, and a symmetric power utilization curve. (VOY: "Dark Frontier")

A transwarp conduit was first observed by the USS Enterprise-D in 2369, during the pursuit of a rogue Borg ship. The conduit could only be opened by a tachyon pulse. (TNG: "Descent")

Later discoveries by the USS Voyager during its journey in the Delta Quadrant revealed that the Borg maintained a vast network of transwarp conduits, allowing the Collective to reach any point in the galaxy. One such conduit opened within a light year of Earth. This conduit brought Voyager back to the Alpha Quadrant after its disabling of the Borg network. (VOY: "Endgame")

Temporary conduits could be generated using transwarp coils, a technology that shared similarities with the quantum slipstream drive of Species 116. (VOY: "Hope and Fear") Such conduits were utilized by Voyager in 2375, after the capture of a transwarp coil. Using the coil, the Delta Flyer was able to open a conduit to Unimatrix 01. Upon its return, Voyager collapsed the conduit for a distance of one light year by sending a spread of photon torpedoes into the opening, destroying it and a Borg diamond. The starship then used the coil to travel a further 10,000 light years towards the Alpha Quadrant. (VOY: "Dark Frontier")

In 2374, Seven of Nine attempted to open a transwarp conduit by modifying the Voyager's main deflector to emit tachyon bursts. Unfortunately the experiment proved disastrous, causing tachyons to flood the warp core and nearly causing a breach. (VOY: "Day of Honor")