Optical Switching

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OPTICAL SWITCHING

The Internet structural backbone's total carrying capacity in the early 2000s was expected to fulfill only a minuscule portion of tomorrow's requirements. With Internet traffic accelerating exponentially and fiber-optic networks facilitating cheaper and faster transmissions, optical switching was the grand prize for telecommunications firms and Internet operators seeking to keep the bandwidth capabilities of the Internet commensurate with growing demand.

The specific purpose of the switches is to route transmissions in the telecommunications network from one point to another. Optical switches send data packets along their route to one destination or another without stopping to convert their signals into electrons, thereby saving time and taking full advantage of the fiber-optic network. Optical switches, in other words, never even touch the transmission itself; they just direct it on its way. Optical switching was slated to replace electronic switching, the traditional means of transmitting telecommunications signals. In the network configuration most widely used in fiber optics in the early 2000s, fiber-optic transmissions were routed through electronic switches, which impeded the capabilities afforded by fiber optics since the signals required conversion into electrons and then back into photons, thereby slowing the speed of the transmission. Optical switches promise to lower the cost of telecommunications, boost transmission speeds, and enhance the quality of signals.

The primary impetus for the development of optical switching was increasing demand for network capacity. While, on the one hand, the Internet provided unprecedented access to a wealth of information very quickly, it conversely created a shortage of patience as users came to expect faster and faster connection speeds. As more and more people accessed the Internet through the 1990s and early 2000s, the demand for faster connections only grew. Businesses, especially, demanded greater network capacity to facilitate quick and efficient transaction speeds and thereby generate sales and maintain customers. To eliminate the bottlenecks that cause connection delays, Internet operators and telecommunications firms increasingly turned to optical switching to fulfill the promise of fiber-optic telecommunications. The technology for optical switching was developing at an astonishing rate. According to Scientific American, the speed of optical fiber transmissions, measured in bits per second, doubles every nine months, twice the rate of improvement for computer chips popularized by Moore's Law.

The fiber itself is a tiny glass core surrounded by a layer of "cladding," both designed with a specific degree of refraction, the degree to which it bends light. The fiber receives the transmission from a laser or light-emitting diode. As the photons travel through the fiber, the signal is amplified by fibers infused with erbium, restoring the signal to its original strength at high speed. Moreover, this amplification system, developed in the 1990s, can amplify the wavelengths of multiple signals simultaneously. Dense wavelength division multiplexing (DWDM), as this process is known, was a key breakthrough for optical switching, because it enables the transmission of large numbers of signals down a single fiber without compromising speed or creating bottlenecks, greatly reducing telecommunications costs and boosting speed and clarity.

Analysts expected that the Internet of the near future will utilize optical switching as the basis for the creation of seamless integrated networks that will transmit all traffic over the same fiber connection and provide alternate routes for traffic to traverse when one channel breaks down. The net result, enthusiasts insist, will be a faster, more convenient Internet.