Jeff Hecht in Nature:
On 19 June, several hundred thousand US fans of the television drama Game of Thrones went online to watch an eagerly awaited episode — and triggered a partial failure in the channel's streaming service. Some 15,000 customers were left to rage at blank screens for more than an hour. The channel, HBO, apologized and promised to avoid a repeat. But the incident was just one particularly public example of an increasingly urgent problem: 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 The copper lines that originally formed the system's core have been replaced by fibre-optic cables carrying trillions of bits per second between massive data centres.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.