Are we headed for a SMARTPHONE MELTDOWN?

(Illustration By Allison Ghaman/the Washington Post; Photo By Istockphoto)
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By Jim Giles
New Scientist
Tuesday, November 30, 2010

The first thing to go might be your smartphone's connection to YouTube, with videos becoming increasingly choppy and then one day just failing to download. In your impatience, you decide to scout out the latest posts in the Twittersphere, except that, too, is temporarily down. Your e-mail is stalled, and even a simple text is now too arduous, as the world's phone networks come crashing down. In the following months, it's almost impossible to get a lasting connection, even for a voice call.

Welcome to 2013, and the first mobile meltdown.

Although this is the worst-case scenario, some kind of collapse in cellular networks in the near future is a real possibility. They are already showing signs of strain: Your phone may temporarily cut out in large crowds or at a sporting event or music gig, and if you live in New York, San Francisco or London, you may have found it increasingly difficult to make calls in your home city.

Data-gobbling smartphones are, of course, the source of the problem, as they overload networks with requests for Web pages, e-mail and video streaming 24/7. The rapid growth in the use of these devices is behind the dire predictions of a meltdown by 2013, Since many core services depend on wireless communication, the results could be devastating. The only solution, according to many experts, will be an overhaul of the way mobile communications are delivered.

Think of it as a road traffic problem. Governments in Europe and the United States allocate five-megahertz chunks of the electromagnetic spectrum to each operator's network, These chunks correspond to the lanes of a highway, carrying data either to or from the operator's transmitter. Many operators are given just two chunks - one lane each way - though some have as many as five pairs.

Like any road, these highways can hold only so much traffic. Current 3G technologies can send roughly one bit of data - a one or a zero - per second over each hertz of spectrum. That means a cell tower using two chunks of spectrum can transmit just five megabytes of data per second, a handful of streamed videos at most.

Cellphone congestion seemed like a distant prospect a decade ago, when the 3G network was rolled out. At that time, pretty much the only smartphone users were business executives on their BlackBerrys, leaving the 3G network massively underused.

Not anymore. Wireless modems added traffic when they emerged around five years ago. In 2007, Apple launched the iPhone and has now sold 50 million of the devices. And many other companies have joined the fray. Suddenly, lots of people are on the highway, each taking up huge amounts of road space. (A single streaming video occupies as much bandwidth as about 100 phone calls, for example.) As a result, the 3G highway is now overcrowded, especially in cities where lots of people use smartphones .

If the growth in smartphone sales continues at the current pace, mobile traffic will more than double every year for the next four years, according to predictions by the network technology company Cisco. Which means that the occasional congestion of today will become gridlock tomorrow, especially in big crowds in sporting events such as the Olympics.

In the past, cellphone companies used innovative engineering to increase capacity. By making the jump from 2G to 3G (G stands for generation), for example, engineers were able to squeeze five to 10 times as many bits per second into each hertz of spectrum, says Simon Saunders of Real Wireless, a consulting firm based in the United Kingdom. This meant more data could rush down the highway without holdups.

Could a similar technique stave off the wireless crunch? Internet traffic often comes in bursts as users click on a page, read, then click again, says Saunders. 3G networks struggle with this kind of traffic, but their successors - Long Term Evolution (LTE) and WiMax - should do better.

These technologies have spent years in development, yet they will let operators cram only roughly 50 percent more data into the chunks of spectrum before holdups will start happening again, a mere drop in the ocean when faced with the rise and rise of the iPhone. If LTE were the only solution in the pipeline, demand might well trump supply in a couple of years, according to a recent report commissioned by Research in Motion (RIM), maker of the BlackBerry.

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