Only way to run across the joists without drilling, is to place a 1x4 to allow the wires to be secured, so that nothing can hang from them. Other way is to drill no more than a 3/4" hole in each joist, no farther than at least 2" from the bottom of each joist. Take your pick, and choose the easiest, which btw, either way is both just as easy as the other.