A Study on Evolution of Optical Fiber Communication from PDH to SDM Technology

In today’s world, long distance communication is a vital part of communication technology. In the field of communication, continuous research is going on for transmission of a greater number of bytes. In this article we discuss the different stages of long-distance communication via optical fiber and we go through the history of optical fiber communication and discuss the different stages of development in the optical fiber communication. This article briefly discusses the following stages of optical fiber communication: i) Plesiochronous Digital Hierarchy (PDH) ii) Synchronous Digital Hierarchy (SDH) iii) Wavelength Division Multiplexing (WDM) iv) Elastic Optical Networks (EONs) v) Space Division Multiplexing (SDM).