From a slightly more technical point of view, Ephremides noted that OFDM-based systems split the signal into different frequencies and simultaneously transmit the signal over a set of small bands spread over a wider band.

"You gain some hedging against impairments such as fading and jamming, which gives it some robustness over [3G systems], but there also are disadvantages," Ephremides said. For example, 3G systems do better in situations with uncontrolled numbers of users.

"If it happens that 200, 300, 400 users show up on the system, [OFDMA systems] will suffer more," he said. "[3G] is more resilient when traffic gets heavy."

Besides the fact that wireless broadband is IP-based, the biggest difference between it and 3G may be non-technical. That difference is that wireless broadband service will be offered by some cellular operators, but also by wireless ISPs.

For example, Sprint recently committed to building a nationwide mobile WiMax network. But so has a much smaller company, Clearwire, which is run by cellular-industry pioneer Craig McCaw. So far, Clearwire provides fixed WiMax service only in a handful of relatively small markets. However, Intel and Motorola recently invested almost a billion dollars to help Clearwire roll out a nationwide mobile WiMax network in the U.S.