With the explosive growth of Internet users, the demand for data communication network bandwidth has increased significantly.By the end of 2000, there were already 29 million Internet domains and still increasing. Digital library, distance learning, e-commerce, video on demand and peer-to-peer sharing all are spawned by these web sites.
Most of the backbone level connections for the Internet are backed by AT&T, Worldcom and Sprint with a standard speed of 2.5Gbps. The network infrastructure has serious difficulty in keeping up with the bandwidth demand and that is why 10Gbps, 40Gbps and even 100Gbps are being deployed and developed by the fiber optic equipment manufacturers.
Future Internet applications will create even more demand on the bandwidth and switching capabilities of these network systems. With the inception of Web 2.0, more bandwidth-hungry applications which extensively uses graphics, images and video are used. The Internet backbone has to keep up with this demand. Actually many carriers have already upgraded their network to 10Gbps and 40Gbps. (although, 100Gbps remains under development at this moment).
On the technology side, ATM (Asynchronous Transfer Mode) over SONET have been adopted as the primary transport mechanism for broadband traffic. Currently, this traffic is carried on single mode fiber between switching hubs for up to 40Gbps.
However, the speed of each fiber cannot be increased indefinitely, when the bandwidth required is more than can be supported by a single fiber, multiplexing technology is incorporated into the system such as TDM and WDM.
There are number of promising technologies for fiber optic data communications. But we have to investigate the potentials and limitations of each technology. These technologies include All-Optical Network, WDM and Wavelength Routing technologies.