Selecting CAT-M1 as the right wireless standard for a commercial IoT product launch, then managing carrier certification across Verizon, AT&T, and PTCRB, catching a hardware RF issue and a carrier classification error along the way.

The Challenge

A Network That Has to Work Everywhere

PDE was approached by a significant player in the electrical utility monitoring industry to bring their IoT monitoring platform to the commercial market on a live cellular carrier network. The devices would be installed on distribution network equipment across wide geographic areas, in locations that could be urban, rural, or anything in between. Choosing the wrong wireless technology would mean either a product that couldn’t connect reliably in the field or a certification path that added years to the timeline.

The Considerations

Two Standards, One Right Answer

When this project began, two new wireless standards designed specifically for low-data IoT devices were being rolled out by North American carriers: CAT-M1 (LTE-M) and Narrowband IoT (NB-IoT). Both ran on existing LTE infrastructure, and both were built for the kind of application our customer had in mind: many devices, each sending a small amount of data at regular intervals.

Narrowband IoT looked favourable on paper; it offered lower power consumption and a more robust link budget than CAT-M1, which in theory made it better suited to marginal signal environments, but the problem was not the technology itself. When we reached out to Canadian cellular providers, we quickly found that the carrier ecosystem for Narrowband IoT wasn’t ready. Despite assurances from carriers, our testing found that Narrowband-IoT coverage just wasn’t there yet and there were no certification programs in place for it.

CAT-M1 had mature certification programs in place on both sides of the border. Our testing confirmed it was the right fit, and the project moved forward from there.

Our Solution

Three Certifications, Managed as One Program

Getting a cellular IoT device to market is not the same as getting it to connect. Carriers require formal certification before a device can be commercially deployed on their networks, and each carrier runs a separate program with its own RF testing requirements, lab relationships, and ongoing obligations.

We managed the certification process across Verizon’s Open Development program, PTCRB (the industry consortium covering AT&T, Bell, and Telus), and AT&T’s network compatibility trial. Along the way, pre-testing at a certified RF lab identified a receiver sensitivity issue on the 700 MHz band caused by electrical noise from the device’s own power supply. We traced the root cause and modified the hardware to resolve it before entering official testing, avoiding a formal certification failure. We also caught a carrier classification error during the AT&T review process that would otherwise have produced an incorrect fail status.

The device achieved certification across all three programs, covering commercial deployment on Verizon and AT&T in the United States and PTCRB-compliant carriers in Canada.

‟customer comment”

— author

The Technologies Behind This Project

Electronics Design
CAT-M1 (LTE-M) Narrowband IoT (NB-IoT)
RF and Wireless
PTCRB Certification Verizon Open Development
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