Wide-band subspace
Wide-band subspace was a type of subspace signal used to communicate when a hail had been ignored or visual contact was not possible. It was a band generally received by most starships.

In 2372, Captain Kathryn Janeway used a wide-band subspace signal to communicate with the Pralor Automated Personnel Units, which had abducted B'Elanna Torres and refused to acknowledge hail requests. ()

Subspace
Communications technology