Sprint's Saw: '5G' Opp Is Moving Signal Closer to Customers

While Sprint's chief network officer John Saw is hoping none of its competitors' jump the gun on launching "5G" networks, he's willing to offer up his own vision of the emerging wireless technology.

According to Saw, the man behind Sprint Corp. (NYSE: S)'s LTE strategy and the former CTO of Clearwire, 5G is an opportunity for the industry to move cellular signals closer to their customers. It's an evolution of wireless that relies heavily on its 4G foundation, which ultimately becomes "personal backhaul for 5G points of presence," he said. (See Radio Revolutions on the Road to 5G and EE Makes the Case for 5G .)

That said, Sprint isn't as gung-ho as many in the industry about jumping into 5G as the carrier has its hands full with evolving its complex 4G network. Saw told Light Reading this week that the network core and backhaul need to be strengthened before the industry gets beyond LTE-Advanced, so 5G will be a long time in the making. 4G was the real inflection point away from circuit-switched to all IP, he said. 5G will build off of that. (See Sprint Goes Live With 8T8R in Chicago, Google's '5G' Buy: Eyeing IPR Ahead?, and Google Buys Alpental for Potential 5G Future.)

"Whatever 5G ends up to be, it will be based on leveraging what we built for 4G," Saw added. "It's the foundational layer for whatever 5G becomes. Hopefully no one jumps the gun on calling it 5G. It has to be really different than what 4G can offer."

That difference might include gigabyte per second speeds with absolutely no lag time, high density sites, and a heterogenous network. Saw said his version of 5G doesn't just include macrosites, but also small cells and IP points of presence backed up by the 4G foundation. (See DoCoMo's 2020 Vision for 5G and NGMN Kickstarts 5G Initiative.)

Sprint LTE small cells in the wild
Speaking of small cells, that's one part of this network vision that the carrier is already underway way on. There has yet to be an official announcement around Sprint's public access small cell deployments, but Saw said the carrier has "a small number" of single-mode LTE picocells in the market and it's working closely with SoftBank Corp. to deploy "Sprint Spark small cells" within the next few months. (See Sprint Tests Small Cells at the Speedway and Sprint Plans Indoor, Outdoor Small Cells in 2014.)

Sprint Spark small cells won't necessarily support all three frequency bands that make up the tri-mode Spark network, but Saw said they might be single-mode 2.5GHz, single-mode 1900 MHz, or dual-mode 1900 MHz and 2.5GHz, depending on the use case.

Right now, Sprint is watching the cost of these multimode small cells as it's thus far been cost prohibitive to pack more than one band into the device. It is working on multimode, however, Saw pointed out that the carrier won't need 800MHz in its multimode small cells, because it is designed for indoor environments and already penetrates walls. It also won't be adding WiFi rather seeing it as complementary to its cellular strategy.

"Our focus right now is on the bigger macro footprint and then to bring in small cells to complement it," he said.

— Sarah Reedy, Senior Editor, Light Reading