Frame restructuring interface for digital bit streams multiplexed by time-division multiplexing digital tributaries with different bit rates

A frame restructuring apparatus for digital bit streams multiplexed by time-division multiplexing digital tributaries at different bit rates according to a synchronous multiplexing hierarchy, said synchronous multiplexing hierarchy including various hierarchy levels at which tributaries can be introduced, said tributaries being constituted by signal entities referred to hereinafter as containers and multiplexing units, the multiplexing units being formed by associating justification and indexing signals to containers constituted at the same hierarchy level for indexing and justifying said containers relative to said multiplexing units, the containers at a given hierarchy level being formed by one of (i) multiplex signals obtained by multiplexing the multiplexing units constituted by a hierarchy level lower than said given hierarchy level and (ii) signals from said tributaries at said given hierarchy level, frames being formed by adding service signals to one of (i) the multiplexing units constituted at a highest one of said hierarchy levels and (ii) a multiplex signal of the multiplexing units constituted at a lower hierarchy level, said apparatus operable with equipment for processing said frames by containers referred to hereinafter as containers to be processed, and said apparatus comprising:

• extracting means for extracting from incoming frames signals constituting said containers to be processed;
• and
• restructuring means for constituting, and for multiplexing into restructured frames subdivided into sections of the same length, restructured multiplexing units respectively representing said containers to be processed, by inserting signals constituting said containers to be processed, as well as indexing and justification signals for adapting extraction and insertion timing rates of the signals constituting said containers to be processed, at locations which for a given container to be processed have ranks within each restructured frame section defined relative to the start of the restructured frame section, said ranks being invariant from one frame section to another and from one frame to another, and each of a set of locations corresponding to the same rank of the restructured frame section being assigned to at most one restructured multiplexing unit.