The Telecom Exchange NYC 2016, New York City -- AT&T is pushing ahead with an all-LTE future for cellular Internet of Things (IoT) applications, despite earlier suggestions that the operator could consider other low-power, wide-area specifications.

As recently as February, AT&T executives were open to at least the possibility of adopting other Low-Power Wide Area Network (LPWAN) specifications. "We prefer the licensed [specifications], but obviously you're going to have multiple other options out there," Chris Penrose, SVP of Internet of Things at AT&T, said at Mobile World Congress. (See AT&T to Test 4G Specs for Unwiring IoT.)

"We did look at those... I think the decision that we have made as a company is that AT&T is going to standardize on the LTE stack as opposed to unlicensed bands," Mobeen Khan, AVP of AT&T IoT Solutions, at AT&T Mobile and Business Solutions, told Light Reading Wednesday.

AT&T has "many reasons" for the decision: The specialized IoT LTE technologies uses AT&T's existing spectrum; it's more secure and can be managed using existing infrastructure. "It has a lot of benefits for our customers," Khan said.

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"We're not interested in the others, unless there's a strong customer need that's driving it for a specific customer. [In that case,] we'll look at it, but otherwise our standard offerings are LTE," Khan elucidated.

AT&T is going to standardize on Cat-M1 (a.k.a. LTE-M) for devices like smart meters and wearables. Cat-M1 is optimized to offer a 1Mbit/s connection but with superior battery life compared to the typical 4G smartphone radio chipset. The operator has just approved its first modules for this specification. There will be trials in the forth quarter.

For even lower-power applications, AT&T will use Cat-M2 (a.k.a. Narrowband-IoT) modules in units like smoke detectors and networked monitors. Cat-M2 is "still being specced out" but is anticipated to go to kilobits-per-second connection rates to further extend battery life, Khan said. AT&T will test Cat-M2 devices on the network in 2017 and hopes to go commercial early in 2018.

This doesn't mean that AT&T won't support any other types of networking for IoT. WiFi, Bluetooth and mesh networking will all be part of the mix.

"We're living in a multi-network world," Khan said.

— Dan Jones, Mobile Editor, Light Reading