System for aligning transmission facility framing bits to the sonet H4 multiframe indicator byte

摘要

A system for aligning framing bits from independent digital transmission facilities with framing of a higher transmission rate facility includes a RAM memory. Received framing bits from the independent digital transmission facilities are stored at RAM locations in accordance with multiframe addresses of the framing bits relative to the multiframe format of the independent facility. Multiframe indicator bytes indicative of the framing of the higher transmission rate facility are used as addresses to read framing bits from RAM. The multiframe address of the independent digital transmission facilities is established by a counter for each independent facility, said counter being synchronized to the framing of the independent facility and incremented to provide addresses identical to the multiframe indicator bytes of the higher transmission rate facility.