In recent years, there has also been a great deal of work spent studying the effects of alternative schedules for variable-node and constraint-node update. The original technique that was used for decoding LDPC codes was known as "flooding". This type of update required that, before updating a variable node, all constraint nodes needed to be updated and vice versa. In later work by Vila Casado "et al.", alternative update techniques were studied, in which variable nodes are updated with the newest available check-node information.