LIVE FROM AT&T BUSINESS SUMMIT – DALLAS, TEXAS: AT&T IoT chief Chris Penrose explained the operator is exploring the use of guard band spectrum for a forthcoming NB-IoT launch in a bid to future-proof the technology.

The operator is preparing to launch the network in Q2 2019. Penrose told Mobile World Live (MWL) deploying in the guard bands would protect NB-IoT services from the impacts of future spectrum refarming as the operator upgrades its legacy 3G and 4G networks to 5G.

Guard bands are fallow gaps of spectrum left between radio frequencies to prevent interference. An operator representative in June told MWL the US network would use its 700MHz, AWS and PCS spectrum, indicating the guard band move could complement those.

Penrose noted using guard bands “gives us the ability to keep it out there longer…Because you’re not taking that spectrum to reuse it, that guard band’s going to be there to do the signalling for any technology that’s out there.”

“It would be nice to be able to go to customers and say one of the benefits of deploying on narrowband is you don’t have to worry about the fact that there might be a network change in the future. That’s always the challenge with all of these technology jumps,” which would be a “nice thing” to avoid he said.

AT&T isn’t alone in recognising the perks of pushing IoT deployments into the guard bands. T-Mobile US launched its nationwide NB-IoT network using the spectrum in July, noting the decision ensured traffic from IoT applications doesn’t compete with wireless customer data.

Verizon said in February it also plans to launch an NB-IoT network using guard band spectrum sometime in 2018.

IoT growth
AT&T does not break out revenue figures for its IoT business, but Penrose said the operator now has 44 million connected devices on its network, including 21 million connected cars. While the vehicle segment is AT&T’s best-known IoT strength, he disclosed there are now multiple verticals with more than a million connections.

“It’s exciting to see a whole slew of verticals that are in the multi-millions now, and I think that gives us a lot of confidence that this has got traction really across the board.”

Penrose tipped smart cities as one major up-and-coming segment, adding public safety is another sector where AT&T expects to see substantial growth over the next 12 to 18 months as it sells solutions as part of its FirstNet rollout.

The executive said the original vision for FirstNet was ensuring reliable wireless communications for emergency workers. But with the advent of the IoT, he said the operator is now able to offer fleet tracking for service vehicles; wearables to track officers and their vital signs; and drones to survey the scene before first responders enter.

Penrose added AT&T is even looking to tie its smart city traffic solutions into public safety applications to help clear a path for emergency services to get to the scene more quickly.