They do both the transmission and the switching of data in the optical domain.Tags: Hbs Case Study Teaching NotesEntrepreneur Essay IntroductionWriting Case Studies For TrainingLetter Writing Paper For KidsEssay On Slavery In Ancient GreeceCensorship In Music Thesis StatementStartup Business Plan Example PdfTkam Boo Radley EssayEthical Dilemma Social Work-EssayExamples Of Research Proposals In Education
The DWDM system has an important photonic layer, which is responsible for transmission of the optical data through the network.
Some basic principles, concerning the optical transmission, are explained in this section.
These are necessary for the proper operation of the system.
The minimum frequency separation between two different signals multiplexed in known as the Channel spacing.
The existing SONET/SDH network architecture is best suited for voice traffic rather than todays high-speed data traffic.
To upgrade the system to handle this kind of traffic is very expensive and hence the need for the development of an intelligent all-optical network.However, these networks still perform the switching of data in the electronic domain though the transmission of data is done in the optical domain.Finally we have the third generation networks that employ Wavelength Division Multiplexing technology.The most important components of any DWDM system are transmitters, receivers, Erbium-doped fiber Amplifiers, DWDM multiplexors and DWDM demultiplexors.Fig 1 gives the structure of a typical DWDM system.Before the introduction of optical networks, the reduced availability of fibers became a big problem for the network providers.However, with the development of optical networks and the use of Dense Wavelength Division Multiplexing (DWDM) technology, a new and probably, a very crucial milestone is being reached in network evolution.Hence carriers can quickly introduce ATM or IP without having to deploy an overlay network for multiplexing.As mentioned earlier, optical networks use Dense Wavelength Multiplexing as the underlying carrier.The concepts of optical fiber transmission, amplifiers, loss control, all optical header replacement, network topology, synchronization and physical layer security play a major role in deciding the throughput of the network.These factors have been discussed briefly in this sections that follow.