Back when municipal Wi-Fi was all the rage, EarthLink still had its shirt and Kelly Clarkson was leading the charts. Companies like Tropos, Skypilot Networks and Strix were providing gear for high-profile city networks that promised to disrupt the established telecom paradigm and free us from the chains of the phone company/cable duopoly. Well, as we know now, it didn’t work out that way, and as Om declared two years ago, muni Wi-Fi turned out not to be “the third pipe.” So what’s become of these former municipal Wi-Fi gear makers?

Several have recently turned to the new new thing in wireless — the smart grid. Last month, it was muni Wi-Fi posterchild Tropos, which announced its wireless networks can enable utilities to build their own wireless smart-grid networks. This morning it’s wireless mesh network maker Skypilot, which is being bought up by smart-grid developer Trilliant. Trilliant didn’t disclose the terms of the sale, but plans to use Skypilot’s wireless gear to connect smart meter data that’s been aggregated on the network to the utility back office.

The new move into the smart grid makes sense for the former municipal Wi-Fi firms. Utilities aren’t used to paying high prices for information technology upgrades, and wireless mesh gear can offer a low-cost option. And the smart grid is offering one of the biggest infrastructure buildouts of the decade.