The global recession weighed down both subscriber additions and the average monthly revenue from business users in the first quarter, according to Maravedis analyst Adlane Fellah. WiMax operators are also running into a variety of other hurdles, including regulation, delayed allocation of spectrum and their own deployment problems, he added.

"I think 2009 is going to be another tough year for WiMax," Fellah said. "It's not declining, but it's not big growth yet."

But WiMax may have a crucial role to play as mobile data traffic rapidly grows in the coming years and potentially strains existing 3G networks, Fellah said. Even carriers that plan eventually to deploy LTE (Long-Term Evolution) may use some WiMax cells to offload data from 3G networks that also have to carry voice. WiMax has a big head start on LTE, which probably won't see wide deployment in most areas until 2012, he said.

The Maravedis survey covered fixed and mobile WiMax, as well as proprietary technologies that preceded the standards-based system. About half of these overall deployments constitute WiMax. But the overall trends in the report apply equally for WiMax, he said.

The number of subscriptions grew about 13 percent in the first quarter of 2009, compared with about 30 percent in the fourth quarter of last year, according to Maravedis. There were approximately 3.5 million wireless broadband subscribers worldwide in the first quarter, about half of them using WiMax, Fellah said. About 400,000 more people signed up for wireless broadband service in the quarter. Still, the number of subscribers was up 70 percent from a year earlier.