PDF of this tutorialDefinition
Dense wavelength division multiplexing (DWDM) is a technology that uses multiple lasers to transmit many wavelengths of light simultaneously over a single optical fiber. Each signal is modulated by different source data (text, voice, video, etc.) and travels within its own unique color band (wavelength). DWDM enables the existing fiber infrastructure of the telephone companies and other carriers to be dramatically increased. Vendors have announced DWDM systems that can support more than 150 wavelengths, each carrying up to 10 Gbps. Such systems provide more than a terabit per second of data transmission on one optical strand, thinner than a human hair. DWDM systems increase the complexity of the network and introduce new challenges for test and measurement equipment.
Overview
Emerging demand for advanced, higher-quality communications poses a paradigm-shifting challenge to the operators of global public telephone networks. Originally designed to primarily carry circuit-switched voice traffic, these networks are now being asked to carry heavy data loads, deliver streaming video, and provide Internet access to rapidly growing numbers of businesses and individual users.
These changes come at a time when network operators are being driven to cut operating costs in response to increased competition brought on by deregulation. They’re faced with a delicate balancing act of overhauling their infrastructures while reducing operating costs and increasing quality of service (QoS) to create competitive differential and address their customers’ needs.
To meet these increased capacity requirements, network operators are either augmenting or replacing existing networks with new infrastructure and new, higher-capacity packet-switch technologies. Primarily, they are deploying photonic networks that deliver greater capacity while reducing operating costs and maintaining QoS.
