Wi-Fi Alliance reaches for peace over unlicensed LTE

If LTE and Wi-Fi can operate peacefully in unlicensed spectrum, mobile users should be able to get a better experience in in crowded areas whether they are using their carrier's service or a Wi-Fi hotspot.

The group will bring together representatives of both sides and lay out proposed guidelines for coexistence between Wi-Fi and LTE on unlicensed frequencies. The workshop, on Nov. 4 in Palo Alto, California, will be the first of several such meetings, the Alliance says.

The goal is to have every unlicensed LTE product tested on its ability to coexist with Wi-Fi. Those tests might be administered by the Wi-Fi Alliance or by another body, said Edgar Figueroa, president and CEO of the Alliance. 

Wi-Fi backers, including Google, cable operators and the Wi-Fi Alliance, have been up in arms over emerging technologies that would let LTE networks use unlicensed frequencies. These radio bands are open to any system that meets some basic requirements for minimizing interference, but Wi-Fi proponents say the way LTE works could cause wireless LANs to get squeezed out. 

Verizon Wireless, T-Mobile USA, SK Telecom and other mobile operators want to deploy so-called unlicensed LTE and offer their subscribers devices that can use the system. That could help carriers deliver better service to more subscribers. But they are up against the massive Wi-Fi industry, which argues that unlicensed LTE could hurt the performance of any wireless LAN that uses the crucial 5GHz band, including consumers' home networks. 

The Wi-Fi Alliance formed a Coexistence Task Group which has drafted guidelines for determining whether an LTE device can live peacefully with Wi-Fi. Most of the major companies associated with unlicensed LTE participated in the group, Figueroa said. 

Those guidelines will be presented at the November workshop along with testing and simulation work that's been going on at the Alliance. Unlicensed LTE proponents, including Qualcomm, Verizon, Ericsson and Samsung, will also make presentations, Figueroa said. 

If mobile device and network makers can agree on tests of whether an LTE product can coexist with Wi-Fi, a path could be cleared for the new breed of cellular gear all over the world. The guidelines worked out in the Alliance don't say anything about how unlicensed LTE devices achieve coexistence, so they could be used for all different versions of the technology tailored to local regulations.

Operators in the U.S., South Korea and some other countries are pursuing a variant called LTE-U (LTE-Unlicensed), while those in Europe are working on LAA (Licensed Assisted Access), with special features to prevent interference. Qualcomm is also developing MuLTEfire, which doesn't have to be anchored to a licensed network. 

Instead of specific solutions, the guidelines are based on key performance indicators for things like throughput, latency and jitter. An LTE product could be certified for coexistence if it didn't send nearby Wi-Fi networks below those performance levels. 

The U.S. Federal Communications Commission is looking into the debate over Wi-Fi and unlicensed LTE, but Figueroa said the Wi-Fi Alliance wants to keep the unlicensed ecosystem the way it is so innovation can continue. 

"An environment with minimal regulation has served us well for over 30 years," he said. "We believe the industry can address coexistence."