By 2011, when PPL decided to expand its DA system to the Poconos, an area of wooded hills and valleys in northeastern Pennsylvania, it had decided against WiMAX for two reasons: first, the area's topography worked against the technology, which pretty much requires a line of sight between the towers and the DA devices; second, the existing WiMAX system had been unreliable. Equipment issues and radio interference had caused major headaches. Figura said they could have solved the first problem “with a lot of repeaters,” which would have raised costs substantially, but, more critically, experience with the existing WiMAX system had “left a bad taste in our mouth.”

Further, he added, the utility began to realize it did not need high-bandwidth communications in the Poconos. “Unless we want video on the side of the pole, I'm personally not convinced we need megabytes of data per second going out to a DA device,” he said, adding that “it takes maybe 200 bytes of data, not even kilobytes, to send the status of a recloser or capacitor — not a lot of data.”

In addition, new communications protocols such as DNP 3.0, which is commonly used in SCADA systems, “records all your events. Why don't I just wait for the device to tell me there's a problem instead of always checking in on it? We don't need to pay for huge bandwidth,” Figura said.

After a year of study — and a change in perspective — PPL has decided on a new communications strategy for DA: commercial cell phones. “We're using the same tower, but it's completely isolated from rest of the traffic. It's a pure Ethernet-based system with a private IP address,” Figura said. “We're seeing about 3 MB/sec of capability, which is about what we're getting from WiMAX.” Latency, he added, is about 200 msec.

Additionally, said Figura, with 80% to 90% of PPL's outages occurring during non-storm events, PPL questioned whether its customers would be willing to spend millions of additional dollars for a private radio system to survive a hurricane. On a final note, Figura said, “Our core business is power, not communications. For AT&T, Verizon and Sprint, that's their business. We have 10,000 sq miles to cover, so it didn't make sense to spend the money to build a system that would survive a hurricane.”