While AT&T was one of the early proponents of mmWave spectrum for 5G, the company has been rather quiet about its 5G spectrum strategy this year.
Speaking at a FierceWireless 5G virtual event this week, Gordon Mansfield, AT&T’s VP of Mobility & Access Architecture, sounded a little like a cross between the executives at T-Mobile and the leaders at Verizon in terms of 5G spectrum.
Mansfield said that while mmWave supports fast speeds, “The reality is until you have a consistent experience across the wider network, it doesn’t matter. We use mmWave in dense areas, venues, campuses and urban areas. We believe in targeted areas that mmWave provides great value and allows you to do amazing things. But you need those interesting capabilities across a wide area.”
The mmWave band AT&T is using is 39 GHz.
AT&T is focused on building a network that has both sub-6 GHz and mmWave capabilities to deliver a consumer mobile experience across a wide area. “That takes multiple layers,” said Mansfield, sounding a bit like executives at T-Mobile who tout their “layer-cake” spectrum strategy, using low-band, mid-band and mmWave. T-Mobile’s President of Technology Neville Ray has said he thinks it’s unwise to focus a nationwide 5G strategy on mmWave. He says 5G needs to be built on a foundation of low- and mid-band spectrum and then topped off with mmWave.
Mansfield said AT&T’s strategy builds on its sub-6 GHz spectrum foundation.
But he also touted the benefits of dynamic spectrum sharing (DSS), a technology near and dear to Verizon’s heart.
DSS allows operators in the U.S. to share LTE and 5G on the same channel. “That’s an important factor as we transition our traffic between LTE and 5G to maintain our experiences for all of our customers,” said Mansfield. “DSS allowed us to get to nationwide in July.”
He added, “I assure you that all operators will in fact use DSS to deliver great services across the wider area of their network over time. It doesn’t mean it’s needed in all cases in all bands, but where it’s needed it’s a great tool, which we and others have and will continue to utilize.
Also speaking at FierceWireless’ RAN event this week, T-Mobile’s VP of Network Technology Development and Strategy Karri Kuoppamaki said, “There’s no question that deploying 5G on free and clear spectrum is the best way forward. But that’s not always possible. That’s where DSS comes in as a way of easing the migration of existing spectrum into both 4G and 5G. It’s more a tool in the tool-box than necessarily the best way to introduce 5G. But DSS is a good tool for sharing spectrum more efficiently between 4G and 5G.”
T-Mobile is in the fortunate position of having a treasure trove of 2.5 GHz spectrum that it obtained from Sprint earlier this year. Sprint was in the early stages of using this spectrum for its 5G build-out, when it got purchased by T-Mobile.
At a September event, T-Mobile's Ray said his competition, especially Verizon, is forced to rely on DSS to bring broad 5G coverage to customers, but DSS also means limited capacity. “Our strategy is to build 5G with free and clear spectrum and utilize DSS as another tool in our toolbox, deploying only where it makes sense."