We now model tr in reconstruction. For the scattered repair,each of the k healthy nodes can read the chunks of a stripein parallel, so the read time for each repaired chunk is c/bd.Each repaired chunk triggers k chunks transmitted over thenetwork, so the transmission time for each repaired chunk isk · c/bn. The write time for each repair chunk is c/bd. Thus,tr = cbd + k · c bn + cbd(for scattered repair). (5)