The company's latest femto market update found that while the residential and enterprise devices struggled in the first half of 2012, shipments doubled in the second half to end the year with around 2 million units shipped. ABI called the changed a "femto bounce" and attributed the upswing to the need to refresh inventory levels as well as newer versions of access points becoming available.

ABI also noted that the market is still held back by operators continuing to view femtos mainly as customer retention tools rather than a competitive advantage to provide better network quality. But if this femto momentum continues into 2013, I think that will raise some important questions for the public access small-cell market in general. If operators are warming up to deploying indoor femtocells to add capacity and coverage where users need it, then how will that affect their plans to deploy licensed or unlicensed (that is, cellular or Wi-Fi) small cells outdoors in big cities? Will they still need public-access small cells if they have enough indoor coverage from femtos deployed in shops or homes?

I don't think these are simple either/or questions. The bigger issue here is about operators' quest for the most cost-effective way to add coverage and capacity to mobile networks that is easy for customers to access. Is the answer to deploy Wi-Fi hotspots, public access small cells, indoor femtocells, or all of these? And where? And if so, then what are the implications for interference, roaming, customer sign-on or billing?

As operators continue to grapple with their Heterogeneous Network (Het Net) strategies, these are some of the questions we'll be pursuing this year here at Light Reading Mobile.

— Michelle Donegan, European Editor, Light Reading Mobile