C-RAN: Old buzzword evolves as part of densification strategies

In our latest feature at FierceWirelessTech, we decided to take a look at some of the activity around C-RAN, which emerged as an industry buzzword a few years ago.

In conventional radio access networks (RANs), radio and baseband processing functionality is integrated inside a base station. With Centralized RAN or C-RAN, it decouples base station functions into distributed Remote Radio Heads (RRHs) at the cell site and centralized Baseband Units (BBUs). RRHs connect to BBUs via a fronthaul network.

While C-RAN has been talked about since at least 2010, it, like so many things in wireless tech, has evolved. Analysts believe it is still in the very early stages of deployment. Operators in South Korea and Japan have been so much farther ahead of the curve given their population density and access to so much fiber.

Things are starting to change, however. According to Tim Howard, research analyst at SNS Research, large outdoor deployments are gaining pace in the U.S. Besides Verizon's deployment in San Francisco, Sprint is investing in C-RAN architecture networking gear as part of its Next Generation Network densification plan.

"U.S. operators are also expanding their fiber footprint to cost-efficiently deploy fronthaul for C-RAN deployments," Howard said. It's easy to see how Verizon's decision to buy XO Communications' fiber-network business for $1.8 billion will give it access to a ton of fiber – about 1.2 million fiber miles, along with the 28 and 39 GHz spectrum that it can use for 5G tests.

A lot of vendors and some operators have a vested interested in seeing C-RAN take off. For the latest on the trends, check out this special report on the topic.--Monica