One Way of Looking at "Small Cells"

Even a casual conversation about the definition of a "small cell" will quickly lead to a series of necessary qualifications and a "fuzzy" answer. Pressed for a concise answer, many observers might point out that a "small cell" approach meaningfully could include every radio installation
smaller than a traditional cellular macrocell.

And that's quite a lot of terrain. It includes "carrier" cell sites of 2-kilometer radius, "pico" cells of  perhaps 200 meters, but also customer-owned "femto" cells that cover indoor areas of perhaps 50 meters, and use the customer's own "backhaul" or "access," not a carrier-supplied link. 

Those are some reasons why the "heterogeneous network" terminology now has become commonplace.  Future mobile networks will use a variety of cell types, with different capital investment parameters and coverage areas.

Future networks also might make much more direct use of both carrier-supplied and customer-supplied backhaul. A carrier public Wi-Fi hotspot might use a carrier-supplied access connection, while, on an informal basis, most smart phone customers use their own fixed network connections, with their devices connected to in-home or in-building Wi-Fi, in place of any of the mobile cell site types. 

Without making too much of the development, "heterogeneous" implies a mix of carrier and consumer-supplied radio and backhaul network resources; a range of management options and quality of service mechanisms. 

One might also say that heterogenous networks and customer offloading to Wi-Fi also represent an unparalleled and new form of asset sharing. Whether by formal contract or simply informal mechanisms, customers are using a mix of carrier and "owned" access to support their "untethered" access requirements. 

While some entrepreneurs continue to work at creating whole networks using end user supplied access and radio assets, the heterogeneous network does the same thing, essentially. In a broad sense, users and their devices are supported by a mix of carrier-owned and customer-owned networks, both "mobile" and "fixed," using mobile air interfaces and simple Wi-Fi. 

The point is that "small cells" are more than a technology. They are part of a shift to more use of "shared" networks in a real sense.