AT&T Has Own Definition for '4G'

AT&T has drawn a line with 4G: it means HSPA 14.4Mbps devices connected to high-speed backhaul at cell sites, according to AT&T senior vice president of devices, Jeff Bradley.

"Our tests show that [4G experiences] happen with Cat-10 devices, or 14.4 ... combined with fast backhaul. That's the key. It's got to be a combination of the two," he said.

The phrase "4G" has become a major marketing term in wireless, but everyone defines it differently. The International Telecommunications Union started out by defining 4G as a set of technologies that no U.S. carrier will have for several years. But as carriers defined 4G down, the ITU basically gave up.

Users "should see faster download times ... in general, the device should show a faster downlink, faster loading of pages and apps should be snappier" on a 4G devices as compared to a 3G device like the iPhone 4, Bradley said.

AT&T's definition varies from other carriers'. T-Mobile has defined 4G as either HSPA 14.4 or HSPA+ 21, depending on who at AT&T you asked and when. Sprint's CEO called its competitors' networks "faux-G" when touting WiMAX, and both Verizon Wireless and MetroPCS insisted that anything short of LTE isn't 4G. LTE is the next step up from HSPA+, and it requires building a whole new network on a different spectrum band. AT&T is planning an LTE launch later this year.

All of AT&T's "high-end" smartphones will be 4G from now on, whether that means HSPA 14.4 like the HP Veer, Motorola Atrix, and HTC Inspire, or HSPA+ 21 like the upcoming (announced at CES) Samsung Infuse, Bradley said.

AT&T's first two "4G" devices were launched with a critical component of the technology missing, though: HSUPA, which speeds up uploads, and which already works on the iPhone 4. Both the HTC Inspire and the Motorola Atrix are getting HSUPA patches now, and AT&T just wanted to get the phones onto the market quickly, Bradley said.

"It came down to a decision about timing of launch. Each platform's different from a chipset standpoint, a radio stack standpoint. The Atrix and Inspire, we would have had to delay launch for UPA ... [and] we had line-of-sight working with both HTC and Motorola for fast-following maintenance releases, which we're delivering," Bradley said. "The device is absolutely 4G capable."
Most people don't see the role backhaul plays in delivering a 4G experience, Bradley said. While a device may be able to offer 4G speeds, it can't do so unless it's linking up with a cell tower that has a fast connection to the wired Internet.

"The overall 4G promise is delivered a bit over time," Bradley said.

AT&T is in the middle of upgrading its network from HSPA 7.2 to HSPA+ 21, which is widely considered to be 4G. But the company can't say where HSPA+ 21 is available on a city-by-city basis, because the upgrade is going piecemeal based on which cell sites are most heavily used. One-third of AT&T's traffic will be on HSPA+ 21 sites by mid-year, and two-thirds will be on HSPA+ 21 by the end of the year, Bradley said.

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