N-GEN Communications Web-based Seminars ©NGCS

Seminar - An Overview of Communications Technologies

Module 5 - SONET, WDM, DWDM and B-ISDN Technologies                                                             Slide 36 of 76 _________________                                                                                  __________

                           SONET Basic Signal Structure - STS-1

                                                Transport Header

                                                STS-1 Envelope Capacity

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STS-1 is the basic SONET signal rate. STS-1 frame has 9 rows and 90 columns of bytes format carrying 810 bytes of "overheads" and "payload".

Transport Header - carries 27 bytes of information containing Section overhead and Line overhead.

STS-1 Envelope - 9X87 bytes carry the STS-1 Synchronous Payload Envelope (SPE) including 1X9 bytes for path overhead.