LTE-U: Just the facts
What was once a highly technical niche issue is now going mainstream in technology circles. Or, as columnist Bill Snyder recently wrote in InfoWorld, “although the issue is pretty technical, involving technologies most people haven’t heard of,” rancor on both sides of this new debate is on the rise.
On one side are mobile carriers like T-Mobile looking to bring a new technology known as LTE-Unlicensed, or LTE-U, to market. According to the wireless providers and Qualcomm, the technology will make use of the existing unlicensed spectrum most commonly used for Wi-Fi. LTE-U is designed to deliver a similar capability as Wi-Fi, namely short-range connectivity to mobile devices.
As billions of mobile devices and Web video continue to strain wireless networks and existing spectrum allocations, the mobile ecosphere is looking for good sources of spectrum. The crunch is significant, and tangible solutions take a long time to develop. According to a recent assessment, it takes at least 13 years to reallocate spectrum from one entity to the private market. And as former FCC Chairman Julius Genachowski and FCC Commissioner Robert McDowell recently remarked, “mobile data traffic in the U.S. will grow sevenfold between 2014 and 2019” while “wearable and connected devices in the U.S. will double” in that same period.
For the meantime, some in the industry have found a partial solution in the 5-GHz ISM band — a good place in which to deploy “small cells” (think miniature cell towers delivering transmissions over a much smaller area), which can greatly enhance the capacity, reach and overall functionality of wireless services.
Google and the cable companies, such as Comcast, however, are opposed to this strategy because they say LTE-U could interfere with Wi-Fi. The engineering department at the Federal Communications Commission has been looking into the matter for the last few months to see whether the objections are valid, but the agency has not yet reported any firm conclusions.
Is this a technical issue Or a business dispute
Based on the dearth of credible evidence demonstrating that LTE-U interferes with Wi-Fi, this looks a lot like the latter. Because of that, I would caution any further FCC involvement in what has forever been a free-wheeling, unregulated space.
The 2.4-GHz and 5-GHz spectrum in which Wi-Fi, Bluetooth and other technologies operate is governed by just a few basic rules. Most crucially, devices must not exceed certain power thresholds, and they can’t actively interfere with one another. Wi-Fi was designed to share nicely, but as everyone knows, large numbers of devices in one area, or large numbers of Wi-Fi hotspots, can cause interference and thus degrade performance. The developers of LTE-U have spent the last couple of years designing it specifically to play by the rules of the unlicensed spectrum and to play nicely with Wi-Fi.
The early results are encouraging. In real-world tests so far, LTE-U delivers better performance than Wi-Fi, doesn’t degrade nearby Wi-Fi performance and may in fact improve the performance of nearby Wi-Fi networks.
Further, as early co-inventor of Wi-Fi Richard Bennet recently wrote, “LTE-U uses a small device in the home, office, or coffee shop the size of a microcell or a Wi-Fi access point. And even when this device is installed, Wi-Fi will continue to serve as an alternate download channel to your phone.”
LTE-U detractors argue that mobile service providers will use LTE-U to deliver services that compete with Wi-Fi and will thus disadvantage competitive service providers. But the mobile service providers already operate lots of Wi-Fi hotspots. They are some of the biggest operators of Wi-Fi hotspots anywhere.
In other words, they already coexist with Google, cable and a host of innovators in this unlicensed space. LTE-U is merely a different protocol that makes use of the same unlicensed spectrum, and must abide by the same rules, as Wi-Fi. The mobile providers just think LTE-U can deliver better performance and better integrate with their wide-area LTE-based cellular networks.
I will be looking for more real-world tests that either confirm or contradict the initially encouraging evidence. Until then, we should not prejudge and block a potentially useful new technology. We should remain optimistic that cooler heads prevail. As Snyder concluded, “Ultimately, all these companies are in the business of transmitting data, and it matters less and less where that data originates, over what spectrum it rides, or what information it contains.”
Bret Swanson, a visiting fellow at the American Enterprise Institute’s Center for Internet, Communications, and Technology Policy, is president of Entropy Economics LLC.