AT&T is in the midst of conducting numerous 5G trials, including a friendly user trial with Intel in Austin, Texas. Most of the tests incorporate millimeter wave (mmWave) spectrum and are checking different types of use cases over a high-speed broadband link. But early test results have yielded few surprises, according to Gordon Mansfield, VP of RAN and device design at AT&T.

“Nothing has really surprised us,” Mansfield said in an interview with SDxCentral. “The whole point of friendly user trials is to learn. And we are learning things as we progress.”

Mansfield said that much of the early testing has involved the propagation of mmWave spectrum, and how things like foliage and weather will impact the connectivity link. To accommodate propagation weaknesses, AT&T has built multiple sites so that when one site is impacted, the traffic will be redirected to another site. This type of redundancy is important in real-world scenarios using mmWave spectrum.

Mansfield added that one of the key advantages of conducting all these 5G trials is that a lot of the equipment that vendors are building for the trials will end up becoming part of the 5G standard. “Vendors don’t have to have commercial grade equipment for the trials,” he said, noting that this is unique to 5G.

Mansfield, who is a long-time AT&T veteran, having previously headed up the company’s small cell initiatives and also chaired the Small Cell Forum, said one thing that is so different about 5G is that operators are conducting friendly user trials, which is allowing the industry to evolve the 5G standard much more quickly.

“No one dreamt of doing friendly user trials in LTE,” he said. “Now we have multiple parties doing prestandard friendly user trials.”

The benefit of these trials is that it is allowing vendors to develop products as the standards evolve and that means that vendors will have commercial products available within months of the completion of the 5G standard.

In contrast, Mansfield said that 4G LTE equipment was not available until at least a year to 18 months after the LTE standard was complete.

The shift to software-defined networking (SDN) is also helping to accelerate the timeline for 5G, Mansfield noted. “The software gives you flexibility with how you route your traffic,” he said. And the subsequent automation of the network, thanks to open source initiatives, is fundamentally shifting the topology of the network.

“The beauty of SDN capability is I can have a common hardware in different locations and can  spin up capacity in different locations. Today you have dedicated hardware and changing gears is not something you can do overnight,” he said.