As Wi-Fi hotspots proliferate, who needs cellular wireless?
Nov 17th 2014/From The Economist
LIKE many others, the first thing your correspondent does when within hailing distance of a public hotspot is switch off his mobile phone’s 3G/4G data network and join the internet courtesy of freely available Wi-Fi instead. He can then download dollops of data without the anxiety of breaching his wireless carrier’s monthly megabyte cap and running up punitive charges. He is not alone. According to comScore, a market research company, more than 42% of mobile-phone traffic, and over 90% of tablet traffic, travels by Wi-Fi instead of the carriers' own cellular networks.
Once, the future of wireless depended exclusively on the mobile-phone companies’ ability to secure enough spectrum in order to beef up their cellular networks. Now, Wi-Fi is emerging as the leading means for delivering ubiquitous connectivity. The widespread adoption of smartphones and tablets is driving this “Wi-Fi first” change of direction. In the United States, 90% of tablet owners bought their devices without a wireless data contract—so confident were they in never needing to access the internet via a mobile carrier’s pricey cellular network.
However, while ideal for distributing broadband around the home, Wi-Fi out in the wild still leaves a lot to be desired. Accessing hotspots found in cafes, shopping malls, libraries, airports, sports arenas and hotels can mean risking either identity theft on an open connection, or answering a web-page of queries and handing over credit-card details—and then paying through the nose for a few hours’ worth of internet access. Even then, download speeds can slow to a crawl as others share the connection’s limited bandwidth.
In an ideal world, one might start the day downloading e-mail on a tablet at home; carry on doing so using a smartphone while waiting for a bus or train; finish off the task on a laptop at work or in a coffee shop—all without having to log on afresh with each change of device and location. If the promise of ubiquitous connectivity is to mean anything, then users will need seamless hand-off from one Wi-Fi hotspot to another, and automatic authentication of their logon and password, no matter the device or network being used. In short, Wi-Fi has to function as transparently as a mobile phone.
At present, it does not. But the technology needed to make this happen is beginning to fall into place. Ironically, it is the mobile carriers that are pushing hardest for it.
Strapped for spectrum, mobile carriers have done an about-face as far as Wi-Fi is concerned. Once viewed as a threat to their precious 3G/4G services, Wi-Fi is now seen as the most cost-effective way of helping mobile-phone companies meet their customers’ insatiable demand for bandwidth. The recent explosion in data traffic—especially among mobile users viewing video on their smartphones and tablets from websites such as YouTube, Netflix and Hulu or using popular messaging apps like Vine and Snapchat—has forced mobile carriers to start building their own Wi-Fi networks.
One reason they are doing so is to prevent the rapidly expanding number of public hotspots—in cafes, stores and other places—from hogging too much of the traffic and threatening their cellular revenues. Another is to offload as much of the video streaming as possible from their congested cellular networks to Wi-Fi's unlicensed public bands. Doing so not only helps them maintain the quality of service for cell-phone customers trying to send text messages or make phone calls, but it also reduces their capital-investment requirements. Installing Wi-Fi hotspots is easier and cheaper than erecting cell towers—or, indeed, having to bid for more wireless spectrum.
Besides, public hotspots can be made to piggyback, at minimal cost, on broadband routers installed in people’s homes. Such home hubs have been widely deployed in Britain, France, Portugal and Brazil. There, cable TV and fixed-line telephone companies have emerged as the dominant Wi-Fi providers. To build loyalty, they have offered subscribers free internet access in exchange for allowing their routers to be used as “homespots”.
Internet service providers (ISPs) in America have followed suit. Comcast, the country's largest ISP, created an uproar this past summer when it added Wi-Fi hubs to its Xfinity internet service in the Seattle area, without first warning customers that their routers would also broadcast a Wi-Fi signal to the neighbourhood to allow other Comcast customers to gain internet access. To be fair, Comcast’s homespots broadcast externally on a different frequency, so the host does not have to share logon details or bandwidth with strangers.
Mobile-phone companies are now doing much the same. In 2013, some 22% of the additional broadband capacity they installed came from establishing public Wi-Fi connections, reckons Maravedis-Rethink, a wireless consultancy. By 2018, three out of four “small cells” (cellular transmitters with ranges of ten metres or so) that mobile carriers use to distribute wireless signals inside buildings and elsewhere are expected to double as public hotspots. AT&T has been adding some 30,000 hotspots a year. Verizon, America’s largest mobile carrier, now has access to over 900,000 hotspots globally.
All told, there are currently over 47m public hotspots and homespots around the world, according to a recent study by iPass, a commercial Wi-Fi network operator. By 2018, that number is expected to soar seven-fold to 340m. There will then be one Wi-Fi beacon for every 20 people on the planet. Naturally, such explosive growth will not be evenly distributed. Americans can expect one Wi-Fi access point for every four people, while Africans will be lucky to see one for every 400.
With unlicensed Wi-Fi blanketing urban areas, the challenge will be how to let people roam from one place to another without having to logon repeatedly and authenticate themselves, while ensuring the “carrier-grade” level of security they have grown accustomed to expect from their mobile-phone company.
This is what the ballyhooed Next Generation Hotspot (NGH) is all about. At the heart of it is a certification process called Passpoint, which implements a Wi-Fi protocol known as 802.11u to automate the whole cumbersome process of network discovery, registration and access—all of which users have to do manually today. For its part, Passpoint ensures that all certified Wi-Fi networks and devices operate seamlessly and securely with one another, to provide a ubiquitous, hassle-free service.
With NGHs broadcasting on the recently vacated frequencies below 700 megahertz (known as “white space”), made available for public use after television broadcasters migrated from sprawling VHF and UHF analogue bands to more tightly packed digital signals, Passpoint-enabled Wi-Fi networks begin to look increasingly like their cellular brethren.
Better still, the Wi-Fi frequencies around 700 megahertz travel for kilometres, carry scads of data, are unaffected by weather or foliage, and have no trouble penetrating concrete walls to flood every nook and cranny of a building’s interior. That is why television authorities adopted such frequencies in the first place (see “Bigger than Wi-Fi”, September 23rd 2010). What was good for watching analogue television yesterday will be better still for streaming high-definition video from the internet using the public Wi-Fi networks of tomorrow.
By opening television’s swathes of white-space frequencies to the public, the Federal Communications Commission (FCC) hoped to trigger another wireless revolution—one potentially bigger than the wave of innovation unleashed over a decade ago when Wi-Fi, Bluetooth and other wireless technologies embraced the unlicensed 2.4 gigahertz band reserved previously for microwave ovens, baby alarms and remote openers for garage doors. With New Generation Hotspots, Passpoint, 802.11u and white space, the FCC could well succeed beyond its wildest dreams.
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