s capacity. These mul- tiplexers essentially split a single fiber into numerous channels, each able to transmit a high-speed stream of light pulses, as shown in Figure 1-1. The current generation of multiplexers are capable of transmitting up to 88 channels of information, each operat- ing at 100 gigabits per second (Gbps). Fiber optics and its associated electronics have evolved to the point where a consor- tium of companies including Google, Japanese carrier KDDI, Singapore Telecommu- nications, and India's Reliance Globalcom are constructing and will operate a six-pair fiber undersea cable with a capacity of 17 terabits per second (Tbps). (One terabit equals 1,000Gb.) That's fast enough to transmit every book in the British Library 20 times per second. The undersea cable will run from Singapore to Japan, with extensions to Hong Kong, Indonesia, the Philippines, Thailand, and Guam. At the time of this writing, it was scheduled to begin operation sometime in 2012. For older networks, once high- quality fiber is installed in trenches, electronics can be added to increase its capacity Matching DWDMs Up to 80 miles distance before signals fade A single strand of fiber-optic cabling with multiple streams of light pulses Figure 1-1 A fiber-optic cable with Dense Wavelength-Division Multiplexers (DWDMs) attached. Key Underlying Technologies to handle the growing amounts of traffic, including high-definition video transmitted along its routes. The costs to dig trenches and lay fiber are many times higher than the costs to upgrade fiber to handle more traffic. This is why spare fiber pairs are included when new fiber-optic cabling is installed. Faster, Lower-Priced Processors: Decreasing Memory Costs Faster multi-core processors, such as those manufactured by Intel, are an integral part of the high-speed electronics used on fiber-optic links. They enable these networks to process multiple streams of light signals simultaneously. They are also at the core of network switches, continually transmitting increasing amounts o