Important SONET and SDH Acronyms & Terms
*** you MUST know these to follow these sections ***
North America Terms
SONET - Synchronous Optical Network
OC - Optical Carrier - a SONET-based data rate where OC-n = 51.84 Mbps x n
STS - Synchronous Transport Signal (standardized by ANSI) - a SONET-based data rate
Europe and ROW Terms
SDH - Synchronous Digital Hierarchy
STM - Synchronous Transport Module (standardized by the CCITT)
STS-1 Synchronous Transport Signal 1: SONET logical standard that defines the framing format and signaling overhead for transmission over OC-1 optical fiber at 51.84 Mbps.
OC-1 Optical Carrier signal 1: SONET physical standard that defines the carrier for the STS-1 frames
FOTS – Fiber Optic Transmission System
STS-n Synchronous Transport Signal "n" : (where n is an integer) SONET standards for transmission over OC-n optical fiber by multiplexing "n" STS-1 frames, (e.g., STS-3 at 155.52 Mbps STS-12 at 622.08 Mbps and STS-48 at 2.488 Gbps).
STS-nc Synchronous Transport Signal "n" concatenated: (where n is an integer) SONET standards for transmission over OC-n optical fiber by multiplexing "n" STS-1 frames, (e.g., STS-3 at 155.52 Mbps STS-12 at 622.08 Mbps and STS-48 at 2.488 Gbps but treating the information fields as a single concatenated payload).
STM Synchronous Transfer Module: STM is a basic building block used for a synchronous multiplexing hierarchy defined by the CCITT/ITU-T. STM-1 operates at a rate of 155.52 Mbps (same as STS-3).
STM-1 Synchronous Transport Module 1: SDH standard for transmission over OC-3 optical fiber at 155.52 Mbps.
STM-n Synchronous Transport Module "n" : (where n is an integer) SDH standards for transmission over optical fiber (OC-'n x 3) by multiplexing "n" STM-1 frames, (e.g., STM-4 at 622.08 Mbps and STM-16 at 2.488 Gbps).
STM-nc Synchronous Transport Module "n" concatenated: (where n is an integer) SDH standards for transmission over optical fiber (OC-'n x 3) by multiplexing "n" STM-1 frames, (e.g., STM-4 at 622.08 Mbps and STM-16 at 2.488 Gbps, but treating the information fields as a single concatenated payload).