April 1st, 2015
In the last post in this series I reviewed several different points of view regarding the pros and cons of cellular carriers using “LTE Unlicensed” (LTE-U) to expand their network capacity. In this post I’ll take a closer look at movement in this direction among U.S. carriers.
[Note: The deployment of LTE in unlicensed bands is referred to by multiple names, including “LTE Advanced in unlicensed spectrum,” “LTE Unlicensed” (LTE-U) and, most recently “Licensed Assisted Access” LTE (LAA). In this post I’ll refer to it as LTE-U, though other names may appear in some excerpts included in the post.]
The two U.S. cellular providers that have so far expressed most enthusiasm for LTE-U are Verizon and T-Mobile.
[B]ased on the discussions I’ve had this week, it appears that Verizon…, Vodafone and other carriers last year decided they wanted to make LTE-U a reality–and they decided they didn’t want to wait for the 3GPP to standardize the technology. So they teamed up with some network technology companies to design real-world tests of the technology…
Verizon clearly has high hopes for the tests and the technology–it has said that it plans to commercially deploy it in the 5 GHz and 3.5 GHz bands in 2016. Verizon is not the only carrier that supports LTE-U/LAA. T-Mobile announced this year that it too will deploy what it calls LAA in the 5 GHz band in 2016. T-Mobile CTO Neville Ray said he believes the carrier can get LAA-capable handsets this year.
As Dano notes, “[h]owever, not all carriers are on board.” Specifically, he points to comments from Tom Keathley, senior VP of wireless network architecture and design for AT&T. As one might expect from a carrier that has invested in a network of more than 30,000 WiFi hotspots, AT&T’s concerns include the risk that LTE-U deployments will not share unlicensed spectrum fairly and efficiently with WiFi.
Keathley said that current approaches to LTE-U are vague about how exactly to check for existing users in unlicensed bands, and how long LTE users can occupy unlicensed spectrum.
Dano also cites comments from Eric Parsons, an executive at Ericsson, a leading wireless network equipment vendor, regarding how these spectrum sharing issues might be dealt with in different regions of the world. As Parsons explains, “there are very specific guidelines in Europe and Japan that cover these areas, but countries like the United States don’t have specific guidelines.”
T-Mobile, which has less licensed spectrum to work with than its competitors (see here for T-Mobile CEO John Legere’s perspective on this issue), seems particularly interested in LTE-U. In anticipation of commercial deployments in 2016, it has announced plans for multiple tests of the technology, in cooperation with Alcatel-Lucent and Qualcomm, Ericsson and Nokia.
In a January 5, 2015 blog post T-Mobile chief technology officer Neville R. Ray shed some light on the company’s plans:
Currently, there is approximately 550 MHz of underutilized spectrum in the 5 GHz Unlicensed National Information Infrastructure (UNII) band, which is available for any use within the FCC’s rules for the UNII band. LAA is a new and innovative approach that allows for licensed and unlicensed spectrum to work seamlessly together. And, we’ve already begun work with our various chipset, radio infrastructure and device partners to bring LAA production trials to life this year and bring the technology to our customers in the near-future.
During T-Mobile’s February 19, 2015 yearend earnings call, Ray provided an update on the company’s LTE-U plans:
[W]e’re looking early ’16 to potentially have the first commercial products in market…I think the first application that you’ll see on 5 gig and LAA will be in-building and it will be primarily in-building commercial, but potentially consumer, too. The great thing is we will move to outdoor. The performance of LTE in the 5 gig band is significantly better, the radio performance, than what’s seen with Wi-Fi.
While Verizon has also been working with vendors on LTE-U and is expected to begin deploying a version of the technology fairly soon, it’s strong spectrum position following the recent AWS auction (you can download Verizon’s post-auction presentation slides here), along with comments by company executives, suggest it feels less urgency than T-Mobile about its LTE-U deployment timetable.
As Network EVP Tony Melone explained during Verizon’s February 17, 2015 investor webcast following the AWS spectrum auction (you can download the webcast’s transcript here):
While we have consistently avoided building our own Wi-Fi networks outside of unique venues such as stadiums, we have always viewed Wi-Fi as complementary to our managed network. As such, we are very optimistic about LTE over unlicensed spectrum as a future capacity solution. With our key suppliers we are active in the standards process and will likely deploy a pre-standard version in the not-too-distant future…
[I]n terms of LTE unlicensed…[y]ou should think about that utilized in a supplemental downlink opportunity. Again, with small cells, utilizing unlicensed spectrum for LTE will be very similar to Wi-Fi in terms of power requirements, etc. So the advantage we will have is we will have centralized control and knowledge of the interference conditions, so we’ll be able to bring that unlicensed spectrum into play when it’s available, when it can provide a good experience for our customers. And again, use it as a supplemental downlink to augment capacity.
The prospect of T-Mobile and Verizon deploying LTE in unlicensed spectrum while cable operators deploy millions of in-home public access hotspots and begin using them to support unlimited-use WiFi-based services (see here, here, here and here), raises interesting and important questions about the future role and significance of unlicensed spectrum. These questions relate to technical standards development, spectrum policy, and difficult-to-predict impacts on competitive dynamics and, ultimately, the public interest. As such, it is an arena worth watching closely by those involved in analyzing and implementing communication policy.