Cisco Systems Inc. revealed that it will eventually round out its small-cell portfolio with the introduction of a Long Term Evolution (LTE)-capable base station in an interview with Light Reading Mobile at Mobile World Congress in Barcelona last week.

But for now, the equipment vendor is more focused on a hybrid approach to small cells that will see mobile data capacity supplemented by carrier-grade Wi-Fi networks and indoor cellular coverage boosted by 3G femtocells. (See Cisco: We're Doing Small Cells Too.)

Critical to Cisco's small-cell strategy are the Hotspot 2.0 upgrades and the Small Cell Gateway that the vendor unveiled in Barcelona last week. The Gateway is based on the ASR5000 Series Mobile Multimedia Core Router and sits in the carrier network to manage connections over small-cell and Wi-Fi connections. (See Cisco Works With AT&T Et Al on First Small Cell.)

Light Reading Mobile sat down for lunch last week with Murali Nemani, senior director of mobility solutions with worldwide service provider marketing at Cisco, who explained that -- 4G or not -- there simply wouldn't be enough bandwidth available to support voice and high-speed data over a licensed spectrum cellular connection.

"We think it is more suitable and sustainable to have Wi-Fi address the capacity needs," said Nemani. "Even if you have all the spectrum available you wanted … It is just not sustainable on its own."

Massive Video Growth
There are a couple of statistics that underlie why Cisco is going for a hybrid approach with small cells. The company expects that by 2015, 70 percent of all mobile traffic will be video. Meanwhile, "80 percent of all access to Internet traffic is going to be indoors," said Nemani.

These metrics favor Wi-Fi offload for data and cellular small cells for voice in home, enterprise and public spaces, according to Cisco. Nemani gives the example of the offload work that his company did with Verizon Wireless at the Lucas Oil Stadium in Indianapolis this year as thousands of fans sent out photos and videos during the Super Bowl.

"It's not the download on smartphones in that situation, it's the upload," said Nemani. "What Verizon and Cisco did together there is basically integrated a carrier-grade Wi-Fi in the stadium."

3G/Wi-Fi Glue
Underpinning this hybrid approach is the Proxy Mobile IPv6 (PMIPv6) protocol used by Cisco across these systems. The protocol involves "carrying an IP address across networks," said Nemani. It allows the user to migrate between cellular and Wi-Fi connections while watching the same video but also maintain a connection while hoping between access points.

Portable Portfolio
Cisco's current small-cell portfolio includes a 3G residential femtocell. AT&T Inc. has deployed so many of these devices, which it brands as a 3G MicroCell, that many believe that Cisco is now the biggest supplier of the indoor 3G base stations in the U.S. (See AT&T Claims to Be a Femtocell Big Spender.)

The femtocell will eventually be followed by an LTE small cell but Cisco is evidently not being rushed into delivering a 4G unit.

"Obviously, we're looking at demand," said Nemani. "It is on the horizon; it is something we’re evaluating with our customers."

— Dan Jones, Site Editor, Light Reading Mobile