Hackers usually exchange scan to find carriers.
We phone losers do it to find not only carriers, but sweep tones, weird recordings, and other fun things. If your goal is simply to find a carrier, you might want to skip this file, and go use a WarDialer. WarDialers automatically exchange scan and look for carriers. I won't get into this, because you could just read the help file for the WarDialer to figure it out. Then put in the date in the remaining space.