Small Cells and Cloud-RAN (CRAN) have always been opposing forces, but they may be able to combine their strengths to create a diverse, applicable network for high-density mobile devices. A new report by Mobile Experts describes how the competing architectures could turn into a heterogeneous network.

The differences between Small Cells and CRAN are stark. Small Cells are low cost and easy to plan. CRAN runs on fiber, delivering the high density and high capacity lacking in Small Cells. However, there’s still somewhat limited access to a fiber network.

Principle analyst at Mobile Experts Joe Madden says, “CRAN has tight baseband coordination with low latency between baseband processers for radio cells, while Small Cells distribute the baseband.” Small Cells have autonomous baseband processors, whereas CRAN can effectively coordinate multipoint reception. Putting a cloud-based network in the mix could help coordinate and exploit the advanced features of LTE.

Problems in uniting the two architectures center on Layers 1-3 (the media layers). Partitioning different functions between Layers 1-3 typically trips up the scheduling function of layer 2 (the data link layer). By re-partitioning the Layer 1-3 processing, however, the work load moves from small cells and behaves like the cloud. The technique opens the door to the coexistence of Small Cells and CRAN.

“The more advanced way is to enable some coordination between the two,” says Madden. “Make changes in the MAC scheduler and listen to what’s going in through the cloud and make changes accordingly.”

More information is available in Mobile Expert’s report: An Unlikely Marriage: Cloud RAN and Small Cells. The report details the approach and the ensuing benefits from the convergence.