Document is the baseline of a series of standards that define a modular family of rates and formats available for use in interfaces generally referered to as SONET. Document describes a base rate and format along with a multiplexing scheme. Other characteristics are layering of overhead, definitions of function and position of overheard, frequency justification, scrambling, conidtions for setting overhead values, and a standardized set of payload carrying envelopes.
ANSI/ATIS 0900105-2008 history
2008ANSI/ATIS 0900105-2008 Synchronous Optical Network (SONET) - Basic Description including Multiplex Structure, Rates and Formats (Includes T1.105a-2002 Supplement)