After months of worry about the future of their WiMAX networks, Clearwire and Sprint are now set thanks to a $3.2 billion investment from Google, Intel and a handful of cable operators. A U.S. 4G network now seems practically assured, though a year or two behind schedule. Clearwire plans to have from a third to half of the U.S. population blanketed in WiMAX by the end of 2010, which is when the first long-term evolution deployments are expected to begin.

That time frame raises the question of whether operators must hurry their LTE plans to keep pace with Clearwire's network. According to the heads of the two wireless associations representing 3G operators, the answer is no. High-speed packet access (HSPA) from AT&T and EV-DO Rev. A from Verizon Wireless can keep pace with the mobile services Clearwire plans to offer, if not WiMAX's higher speeds, said Perry LaForge, executive director for the CDMA Development Group, and Chris Pearson, president of 3G Americas.

While the DSL-like connectivity Clearwire sells may not be able to be replicated on a 3G network, apps connecting devices such as hand-held multimedia computers, digital music players and cameras are all possible, LaForge said. Even the most basic mobile broadband service, laptop connectivity, is something that 3G operators have been doing for years. The device ecosystem for 3G also is more established. While WiMAX has produced only wireless PC cards, EV-DO and HSPA chips are already being embedded in computers and e-book readers. 3G networks also have nationwide coverage. Add all of those together, and 3G can counter WiMAX for the next several years, until Clearwire can achieve the scale and footprint to take advantage of the technology's superior capacity — and by that time, LTE will have arrived, LaForge said.

“For WiMAX to be wildly successful, for it to have a big enough impact on Verizon Wireless and AT&T to get them to alter their plans in the short term — I think that's highly unlikely,” LaForge said.

Pearson even takes issue with the idea WiMAX is faster than 3G. The multiple antenna architectures used by Clearwire may be faster than AT&T's flavor of HSPA, Pearson said, but once UMTS evolves, it will match WiMAX's smart antennas and higher-order modulation, offering 42 MB/s of downstream capacity to WiMAX's 46 MB/s. AT&T has said it will deploy HSPA+ but not given a timeline. Pearson said, though, that HSPA+ is already in trials, and networks will be in place by 2010.

“You have to compare apples to apples,” he said. “Everything that WiMAX is talking about delivering can be delivered by AT&T and Verizon.”