Scientific America

With global Internet traffic growing by an estimated 22% per year, the demand for bandwidth is fast outstripping providers' best efforts to supply it. Although huge progress has been made since the 1990s, when early web users had to use dial-up modems and endure 'the world wide wait', the Internet is still a global patchwork built on top of a century-old telephone system. The copper lines that originally formed the system's core have been replaced by fibre-optic cables carrying trillions of bits per second between massive data centres. But service levels are much lower on local links, and at the user end it can seem like the electronic equivalent of driving on dirt roads. The resulting digital traffic jams threaten to throttle the information-technology revolution. Consumers can already feel those constraints when mobile-phone calls become garbled at busy times, data connections slow to a crawl in crowded convention centres and video streams stall during peak viewing hours. Internet companies are painfully aware that today's network is far from ready for the much-promised future of mobile high-definition video, autonomous vehicles, remote surgery, telepresence and interactive 3D virtual-reality gaming.

That is why they are spending billions of dollars to clear the traffic jams and rebuild the Internet on the fly—an effort that is widely considered to be as crucial for the digital revolution as the expansion of computer power. Laying new high-speed cable is just one improvement. Researchers and engineers are also trying several other fixes, from speeding up mobile networks to turbo-charging the servers that relay data around the world.