N-GEN Communications Web-based Seminars ©NGCS

Seminar - An Overview of Communications Technologies

Module 5 - SONET, WDM, DWDM and B-ISDN Technologies                                                              Slide 69 of 76 _________________                                                                                  __________

                                              What is DWDM ?

                                            Light Spectrum Usage

                                            Multi-Channel DWDM Systems

                                            Submarine cable Systems

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Light sources are capable of transmitting light pulses at a high frequency that can carry information in Tera bps range. Pure Silicon fiber is capable of transmitting data at a very high speed without needing amplifiers and repeaters. Developers slice the light spectrum finely to squeeze 16 or higher wavelength channels through a single fiber - known as DWDM.

A single fiber can carry 800 G bps, 80 light waves each carrying 10 G bps. This has helped to lower the cost of the outside plant for carriers at the same time creating a fiber glut in the industry. 

Lucent Technologies delivered 80 channel system in 1999. Pirelli is developing a 128 channel system.

Submarine cables are using DWDM systems to carry data. Atlantic Crossing 1 began with 2.5 G bps at 4 wavelength channels on its 4fiber pairs. Other European systems are capable of carrying 160 G bps.