Synchronous Optical Network is a physical layer standard that defines voice, data, and video delivery methods over fiber optic media. It defines data rates in terms of optical carrier (OC) levels.
(In topic `Network Architectures`) SONET (Synchronous Optical NETwork) is a fibre-optic transmission system for high speed digital traffic. It is a format that uses TDM to enable different types of formats to be transmitted on one line. Used in North America, its counterpart in Europe is SDH. (see SDH). 
Synchronous Optical Network
Synchronous Optical Network
Synchronous Optical Network, standards for high bandwidth fibre optic networks defined by ANSI (American National Standards Institute). SDH (Synchronous Digital Hierarchy) defined by European Telecommunications Standards Institute is used outside North America.
(NETWORK GLOSSARY) Synchronous optical network. High speed (up to 2.5 Gbps) synchronous network approved as an international standard in 1988.
Synchronous Optical Network. A standard for a worldwide digital network using a common transport. SONET can run over copper or fiber.