Subspace layer

A subspace layer is a region of subspace.

In 2372, USS Voyager encountered Suspiria and learned of Exosia, which was described as a "subspace layer of pure thought and energy". 

In 2375, Voyager became stuck on a subspace sandbar, which is a subspace layer in which the barrier between normal space and subspace is unstable. 

In the same year, the "telepathic pitcher plant" entity appearing as a wormhole, sensed that Seven of Nine was immune to its manipulation. It convinced the crew of the Voyager, that Starfleet on the other side had asked to put her in a stasis, because the wormhole passed through a layer of subspace monitored by the Borg and her neural transceiver might attract their attention. 

Subraumschicht