AT&T already launched its initial mobile 5G network in parts of 12 U.S. cities last December, but it’s now preparing for full nationwide coverage — a dauntingly large task that its millimeter wave small cells won’t be able to handle alone. This morning, the carrier revealed that it will “offer nationwide 5G coverage with our lower band spectrum,” specifically the sub-6GHz frequencies discussed in our interview with AT&T VP Gordon Mansfield yesterday.

While the announcement isn’t entirely surprising given that AT&T began to distinguish between “5G” and “5G+” in December, noting that it planned to call high-speed millimeter wave service “5G+” and offer it only in select high-traffic areas, this is the first official confirmation that AT&T’s nationwide 5G network will rely upon aggregating lower-bandwidth radio signals, which spread more widely from larger towers.

Rival T-Mobile has similarly said that it will use low-bandwidth towers for its nationwide 5G network, while Verizon has focused largely on “true 5G” using high-capacity millimeter wave spectrum. Even so, all of the carriers will eventually rely upon more than one radio band to provide 5G service.

Each carrier is expected to convert some of its existing LTE spectrum into 5G spectrum, though there’s a substantial likelihood of a speed penalty for doing so — enough that there could be a noticeable performance gap between millimeter wave and sub-6GHz 5G networks. AT&T specifically says that it plans to “begin deploying that lower band spectrum in the second half of this year,” suggesting that the allocation of some existing LTE spectrum for 5G will happen sooner rather than later, supporting an already announced Samsung sub-6GHz smartphone.

In the transition from 4G to 5G, AT&T says that it has brought two interim technologies into more markets than expected: 1Gbps LTE-LAA is now in parts of 55 cities, with its controversially named “5G Evolution” or “5G E” — actually just 4G LTE-Advanced — in over 400 markets, offering roughly 400Mbps speeds on select 4G devices. Towers with the 5G E hardware will be capable of flipping to actual 5G service in the near future, but until then will confuse 4G users into believing that they’re using 5G technologies.

AT&T also said that it is expanding its agreement with AR purveyor Magic Leap to include business solutions, including manufacturing, retail, and health care applications. Magic Leap’s current-generation hardware has no cellular hardware, but the company is expected to offer a 5G version in the future, in partnership with AT&T.