Multiplex Structures of the Optical Transport Network

Abstract

This chapter will describe the transported payload capabilities of the Optical Transport Network (OTN). Since the introduction of the OTN in 1990, the initial capacity of 155 Mbit/s, based on the transport capabilities of the existing Pleisiochronous Digital Hierarchy (PDH) network, has grown to the current 40 Gbit/s. Up until about six years ago, the payload of the OTN was mainly used to transport voice traffic, and the multiplexing structure of the OTN was based on this traffic. At that time a consensus emerged among major market researchers indicating that, while voice traffic will continue to grow at a moderate rate, the transport of data traffic will dominate most networks by the years 2002–2005, requiring more bandwidth than was anticipated.