Method and device for demapping a tributary recovering lower order synchronism

It is disclosed a method of demapping a tributary from a first frame into a second frame, the first frame comprising a plurality of tributary words and a synchronization word, the method comprising: providing a first and a second counters; increasing the first counter by a first value at each clock cycle of the second frame; and performing reading operations according to the second counter. It further comprises: generating synchronization information according to the synchronization word; according to the synchronization information, performing a change of state between a first state and a second state, wherein, in the first state, the second counter is synchronized to the first counter at each clock cycle of the second frame, and in the second state, the second counter is synchronized tothe first counter at a predetermined instant of the second frame and the second counter is increased by a second value at each clock cycle of the second frame wherein the reading operation is performed.