CHICAGO – What's that old saying: I can't miss you if you won't go away. That seemed appropriate for day 1 of the 4G World 2009 event held this week in Chicago where while the focus of the conference is obviously on "4G" technologies, those pesky 3G networks remained a major topic of speakers and attendees.

Keynote speakers from both domestic (AT&T Mobility's Kris Rinne) and international (Michael Rocca from Australian operator Telstra) operators laid out coherent arguments as to the continued operating benefits of 3G technologies while at the same time making sure to acknowledge the future benefits of 4G technologies.

AT&T Mobility, which has come under increased pressure from competition and consumers to upgrade its current network, touted its recent announcement that it planned to upgrade its current 3G HSPA network to the 7.2 standard beginning later this year with plans to cover 90% of its network with the enhancement by the end of next year. This came on top of the installation of a HSPA channel in its 850 MHz spectrum to help both capacity and coverage.

However, AT&T Mobility's plans to install HSPA 7.2 across its network by the end of 2010 bump into its plans to begin trialing LTE around the same time with an eye on commercial deployments beginning in 2011 that seem to indicate the HSPA 7.2 plans are the end of its upgrade plans for its 3G network.

Rinne said the carrier was looking at HSPA+, but that it had no specific time in mind for deployment. When questioned further on those comments Rinne indicated that the carrier would shift its focus to LTE and away from HSPA enhancements in the 2011 time frame.

In the meantime, Rinne said AT&T Mobility was very confident its HSPA 7.2 plans would provide a compelling platform for consumers as the multi-megabit network speeds could handle most mobile broadband needs and that the availability of device supporting the technology, which includes Apple Inc.'s iPhone, would far surpass what would be available for LTE through the end of next year.

"We are going to hit the sweet spot with LTE deployments" from a user experience point of view, Rinne added.

Rinne also said AT&T Mobility was still evaluating a 3G femtocell product, but that it was not currently planning to use the equipment to bolster its 4G network deployment plans, though that could change over time.

Spectrum is key

To support its LTE plans, Rinne said AT&T Mobility would use a combination of its 700 MHz AWS spectrum holdings. The carrier could add further capacity from its 850 MHz and 1.9 GHz spectrum portfolio currently supporting its legacy 2G and 3G networks once a substantial portion of its customer base moves onto its 4G network. This re-farming of network capacity could be important if comments earlier in the day from Yankee Group senior research fellow Phil Marshall that carriers could need as much as 100 megahertz of spectrum to support 4G networks comes to fruition.

Marshall added that this need for spectrum to support 4G services would be the limiting factor for carriers looking to make the jump from 3G. Carriers that are limited both by their own spectrum holdings or by government regulations over how they can use spectrum will likely look to evolve their current 3G networks down the HSPA+ path, while those with ample spectrum holdings will look to take advantage of the network efficiencies available from LTE.

Doing things different down under

One carrier intent on riding the HSPA path to the end is Australia Telstra. The carrier's group managing director Michael Rocca said the carrier was on track to soon announce upgrades to its HSPA network that would allow theoretical network speeds in excess of 20 megabits per second and that its road map ran through to 168 Mbps of theoretical throughput using advanced, and yet to be approved, HSPA enhancements. Once exhausted, the carrier's road map finally jumps to LTE.

3G America's President Chris Pearson acknowledged that while Telstra's HSPA enhancement plans might be the extreme, it does show that carrier's are looking to squeeze every possible advantage our of their 3G network investment and that the technology has the capability to compete against the most-hyped 4G network solutions, at least for the near term.

"I think everyone is eventually looking for some sort of 4G migration," Pearson said. "But, the work on enhancing HSPA shows that beyond the marketing hype behind 4G, current 3G technologies can support most needs for high-speed mobile Internet access."