We ask a lot of our phones today — video streaming, video calling, virtual reality — and we expect the network to keep up. The problem: There’s only so much spectrum in the airwaves for data.
That’s why the companies who make mobile modems are casting their eyes on the unlicensed spectrum that’s typically reserved for Wi-Fi. Qualcomm just announced its X16 modem, which taps into that spectrum to achieve the ludicrously fast speed of 1Gbps, or gigabits per second.
That’s the theoretical best-case-scenario spec, but it’s impressive nonetheless. However, Qualcomm’s wireless tech needs to coexist peacefully with Wi-Fi to go that fast.
Some heavy hitters in tech say it doesn’t. Last December, Google, Microsoft, Comcast and others asked the Federal Communications Commission (FCC) to step in before this new generation of modems — which tap into unlicensed spectrum with a tech called LTE-U — start to appear, potentially slowing Wi-Fi networks to a crawl. Since the two wireless technologies use the same spectrum, there’s big potential for interference.
Qualcomm, Verizon and others say they’ve specifically designed their LTE-U modems to make sure that doesn’t happen. Technologies like “listen before talk” mean LTE-U signals have “good manners” around Wi-Fi, reducing the chance of interference. Their tests, they say, show Wi-Fi is virtually unaffected by LTE-U.
Google and others say their own tests show the opposite. Google’s letter to the FCC said LTE-U “coexists poorly” with Wi-Fi, and another study showed LTE-U, depending on how it’s configured, can impede Wi-Fi by up to 80%.
However, that study is from CableLabs, a global consortium of cable companies. And parties like Google and Comcast clearly have a lot of self-interest in discouraging people to consume less data on mobile networks and more on their own — whether over Wi-Fi or home Internet connections. The Wi-Fi Alliance, which includes member companies from both sides of the debate, is attempting to lead the charge in settling the interference issue with a series of tests and workshops.
For now, Qualcomm is plowing ahead with LTE-U in components like the X16 modem and its flagship Snapdragon 820 chip, which will begin to arrive in smartphones early this year (look for it to feature prominently at this year’s Mobile World Congress at the end of February). The main criticism of studies that show interference with Wi-Fi is that the LTE-U signals are simulated.
The worst-case scenario would be that Wi-Fi interference is only clearly established after LTE-U devices are deployed at scale. But even in that case, LTE-U components could be adjusted or disabled via firmware updates, and modems like the Qualcomm X16 have a host of technologies besides LTE-U that make them faster than the previous generation.
Qualcomm’s new super modem and other LTE-U components promise new features and an improved mobile experience with their heretofore unheard-of data rates. But if the critics are right, and LTE-U doesn’t play nice enough with Wi-Fi, that ultra-fast mobile future may soon hit a big speed bump.