Meeting the demand for mobile everything
In the U.S. and in many other countries, cellphone use has become all but universal. In this country, the penetration of cellphone subscriptions is now 104%, meaning that there are more subscriptions than people. In a number of other developed countries, the penetration rate is even higher.
And data accounts for virtually all growth in mobile usage: even as voice traffic has shown virtually no growth over the past decade, mobile data traffic (which includes everything from texting and email to mobile web surfing and video streaming) has grown exponentially. Internet access is going mobile, and for most people, their cellphone is now the main gateway to being online.
Carrying all of this traffic is a wireless infrastructure that consists of two complimentary components — the nation’s cellular networks, which are licensed by the government, and a diverse collection of unlicensed Wi-Fi hotspots in homes, offices and public places. Interestingly, each of these two alternatives were responsible for carrying about half of all mobile data traffic in 2014, according to Cisco’s VNI. In fact, Wi-Fi is often used to help carry the data traffic being generated by mobile phone subscribers.
Both types of access have grown and evolved to accommodate the explosive increase in demand for wireless connectivity. In 2014, for example, wireless carriers invested more than $32 billion to expand and upgrade their networks, while the number of Wi-Fi access spots also grew. Both cellular and Wi-Fi technologies have gone through a series of upgrades that have greatly increased their efficiency and capacity.
And we’re still at the beginning of the mobile data explosion: By 2020, according to a prediction by Benedict Evans of Andreessen Horowitz, 80% of all adults on earth will be using a smartphone. And millions, perhaps billions, of objects – industrial machines, household appliances, tractors and automobiles, even our own bodies – will be online as part of the emerging Internet of Things. Cisco forecasts that by 2019, the total volume of mobile data traffic in the U.S. will have increased sixfold, and nearly three-fourths of that traffic will be video content that requires substantial bandwidth.
Accommodating this surging demand will require innovative new approaches to use the finite amount of spectrum that exists. It will also require policymakers and regulators to play their part in making spectrum available.
A recent report from the Aspen Institute Roundtable on Spectrum Policy, “Making Waves: Alternative Paths to Flexible Spectrum Use,” by Dorothy Robyn, provides an account of the history of spectrum regulation. The Federal Communications Commission (FCC) is the body responsible for regulating spectrum use, and it has been in this business for a long time.
Nearly 90 years ago, the Radio Act of 1927 gave the federal government the authority to designate specific bands of the electromagnetic spectrum for particular uses and to grant exclusive use of portions of these bands to individual users based on the criterion of serving the public interest. The original focus for this scheme was to avoid interference between AM radio stations. This “command and control” approach is still used by the FCC to regulate many uses of spectrum, including radio and TV broadcasting, satellite communications and cellphone services.
However, starting in the mid-1990s, the FCC began experimenting with alternatives to this top-down approach. In 1993, for example, Congress gave the FCC the power to introduce a market mechanism for spectrum allocation by holding auctions for licenses for non-broadcast wireless services. Since then, the FCC has held several successful spectrum auctions that have generated billions of dollars in income for the government.
The FCC also developed another approach to spectrum regulation that involves designating certain portions of the spectrum for unlicensed use. Under this approach, anyone who meets certain technical standards designed to minimize harmful interference with other users can use these spectrum bands without permission from the FCC. The growth of Wi-Fi, which is perhaps the most familiar form of unlicensed spectrum use, is a good demonstration of the success of this approach. As evolving technology has introduced new capabilities for avoiding interference, the FCC has relaxed its rules to permit more flexible use of unlicensed spectrum.
Recently, wireless carriers and high-tech equipment makers have proposed a new type of service called LTE-U – an extension of the current fourth-generation wireless network standard known as Long Term Evolution (LTE) that will make use of unlicensed spectrum in the 5GHz band. A device such as a smartphone using LTE-U would remain connected to a cellular network while getting additional bandwidth from a nearby LTE-U access point. This new technology is particularly intended to provide a convenient way to expand capacity for mobile consumers in congested areas.
Wireless carriers view LTE-U as an evolutionary technology that will enhance the wireless experience for consumers and provide a platform to support a variety of new products and services as the Internet of Things takes hold.
Despite the evident benefits of LTE-U, there is one major obstacle to its deployment: The 5GHz band where it will operate is already being used for Wi-Fi service, and providers of Wi-Fi like cable companies have raised concerns that the new technology will interfere with the performance of Wi-Fi hotspots. In particular, they worry that early versions may be deployed without sufficient safeguards against interference with other users of the band. As one critic put it, “Like a rude talker at a dinner table, these early versions [of LTE-U might] simply talk loud enough to make it hard for [others] to be heard.”
There is really nothing to be gained by improving the performance of wireless service if it comes at the expense of Wi-Fi, which virtually all wireless phone subscribers also depend on. In the long run, the viability of any new unlicensed technology depends on its ability to coexist peacefully with other services that use unlicensed spectrum.
Fortunately, today’s technology offers new ways to avoid conflicts between multiple users of the same spectrum band that can make more intensive use of the spectrum possible. Proponents of LTE-U note that the standard includes several “etiquette protocols” to ensure that it operates politely by seeking the least congested bands to use and by sharing existing spectrum fairly when a band is congested. In fact, LTE-U advocates argue that LTE-U has been designed to be as good or better a neighbor to Wi-Fi than adjacent Wi-Fi nodes currently are to each other. They also note that LTE-U is likely to be deployed initially in locations like offices and on corporate campuses where cell signals are often weak. Commercial customers are unlikely to welcome any technology on their premises that disrupted their existing Wi-Fi networks.
Perhaps what is most noteworthy about LTE-U is that it blends licensed and unlicensed spectrum use in a novel way. Opponents have attempted to portray LTE-U as an unwarranted intrusion into the unlicensed domain by large, licensed operators. Supporters point out that the fundamental concept of unlicensed spectrum is that it should be open to everyone as long as they play by established rules, and that erecting special regulatory barriers to LTE-U to delay its deployment would violate the notion of permission-less innovation that has been a key rationale for designating portions of the spectrum for unlicensed uses. Unlicensed has always been a place for experimentation and innovation and it would be unfortunate to abandon this policy just to avoid a hypothetical problem.
Meeting the ever-growing demand for wireless data connections will require increased capacity through robust growth of both licensed and unlicensed spectrum technologies. But one cannot evolve in a vacuum at the expense of the other. Since LTE-U offers a means for enhancing the mobile experience of millions of consumers and could become part of the solution to a looming spectrum crunch, it deserves an opportunity to prove that it can coexist peacefully with Wi-Fi.
Richard Adler is a distinguished fellow at the Institute for the Future in Palo Alto, Calif. He has written widely about the future of broadband and its impact on fields such as education, healthcare, government and commerce.