Cable players hint at a return of the femtocell

AT&T first announced its MicroCell femtocell roughly a decade ago. (AT&T)

CableLabs, the nonprofit research organization of the cable industry, recently began discussing the possibility that some cable operators could deploy femtocells in order to better handle indoor cellular traffic, thus relieving potential congestion on outdoor networks.

Such deployments would essentially broadcast a tiny bubble of cellular connectivity inside a user’s home or office, and would route that traffic onto a cable operator’s Docsis network.

“When selectively deployed alongside home Wi-Fi hotspots, indoor femtocells give the converged operator the chance to capture the majority of indoor traffic with an indoor radio, freeing the outdoor radio to better serve outdoor traffic,” wrote Joey Padden, a distinguished technologist for wireless, in a CableLabs post.

Those comments are noteworthy considering femtocells were a hot topic among wireless network operators roughly a decade ago. Such products were deployed by the likes of Sprint, AT&T and others as a way of improving cellular reception inside users’ homes—if they weren’t close enough to an outdoor cell tower.

Indeed, Sprint in 2012 disclosed that it had deployed fully 1 million femtocells. More recently, Alaskan carrier General Communication Inc. said in 2016 it would partner with ClearSky Technologies to roll out and manage residential femtocells for its customers in an effort to boost coverage.

However, femtocells have mostly fallen by the wayside likely due to the expense of deploying the gadgets and the overall improvements in wireless coverage in the United States.

CableLabs’ Padden acknowledged that femtocells aren’t new. “But with the new technologies developed by CableLabs, for the first time, they can be done right. Gone are the days of failed GPS lock, poor handover performance and interference issues … From a spectral and economic viewpoint, femtocells over Docsis are poised to be the most efficient deployment model for 4G evolution and 5G cellular densification,” he wrote.

When questioned on the topic, a CableLabs spokesperson explained that Padden’s post stems from the work that CableLabs is doing in the Telecom Infra Project’s vRAN Fronthaul project. That project in part is working on technology that could power virtualized Radio Access Networks in “non-ideal” backhaul scenarios, like via Docsis networks.

Further, the project has shown some progress: Last month, Aricent, Benetel, Phluido and Tech Mahindra announced a virtualized LTE RAN reference solution “under the guidance of CableLabs.”

The companies said their reference design addresses some of the challenges of running virtualized RAN functions over a Docsis network “such as latency, jitter and limited capacity.”

“In this way, cable operators can benefit from RAN virtualization and centralization, while reusing existing Docsis network infrastructure as transport,” the companies said in their release.

In his post, CableLabs’ Padden cautioned that femtocell products working on Docsis networks aren’t necessarily designed for cable operators running MVNO services. That’s noteworthy considering two of the nation’s largest cable operators—Comcast and Charter—are doing just that. Instead, Padden noted, femtocells may be of interest to cable operators that have “both cellular operations and traditional cable hybrid fiber coax (HFC) infrastructure.”

While cable providers that meet those qualifications—meaning, those that own both Docsis and mobile networks—are currently few and far between, their numbers may grow given the interest that some cable companies have shown in deploying wireless technologies. For example, Charter just this month said it will conduct tests in the 3.7-4.2 GHz band in part to better understand the impact of 5G C-Band waveform on C-Band satellite receivers.

But even if cable operators don’t move to deploy mobile services directly to end users, some analysts still see them playing a major role in an increasingly converging telecom industry.

“Very few cable operators own spectrum or have a mobile offering over licensed spectrum,” wrote Paolo Pescatore, SVP of consumer services at MIDiA Research, in a recent blog post. “For this reason, it will be difficult for them to compete with carriers that own 5G spectrum. Despite this, there is an opportunity for cable providers to be relevant in the new 5G world. In particular by providing backhaul capacity, which will be more important in delivering 5G efficiently than current 4G networks.”