Complex sentence: Bit stuffing may be used to synchronize several channels before multiplexing or to rate-match two single channels to each oth include Plesiochronous Digital Hierarchy and Synchronous Digital Hierarchy.
Split into simpler sentences: Bit stuffing may be used to synchronize several channels before multiplexing or to rate-match two single channels to each other. Applications include Plesiochronous Digital Hierarchy and Synchronous Digital Hierarchy.