The Hochkurz mash is a specific schedule of rests achieved with a well defined decoction mash technique. You can read more about it at the link below. It can be done using a biab mash but it does require a second kettle to boil the grains.
http://braukaiser.com/wiki/index.php/Decoction_Mashing#Hochkurz_Double_Decoction