Cox -- America's third-largest cable TV company -- confirmed it hopes to conduct a significant test of 3.5GHz CBRS spectrum and equipment. Specifically, the company asked the FCC for permission to conduct field trials "to determine CBRS capabilities" using 50 Ruckus outdoor access points in locations in Phoenix and Atlanta.

A company representative described the effort as a "generic technology test," and said the company tests a range of technologies as part of its business. Thus, the tests do not necessarily reflect concrete plans for a pending commercial launch of services.

Cox could use CBRS spectrum for a range of potential wireless services, from a commercial mobile service offering for smartphones, to a fixed wireless offering that could extend the reach of Cox's existing wired Internet service, to a private wireless network for the company itself or its enterprise customers.

The timing of Cox's testing request is noteworthy considering the company registered late last year to participate in the FCC's upcoming 24GHz millimeter-wave spectrum action. But, in the intervening months, Cox apparently decided it wasn't interested in those licenses because the FCC this week disclosed that Cox and Frontier were among the companies that were not deemed as qualified to participate. It's unclear exactly why Cox was not qualified to participate, but the company may have not issued the required upfront payment.

Based on the timing of these developments, it appears that Cox may have soured on the notion of purchasing spectrum in the FCC's 24GHz mmWave auction, but still might be interested in some kind of wireless play via 3.5 GHz CBRS spectrum.

Both CBRS and mmWave spectrum can be used for 5G services.

The 3.5GHz CBRS band is much different than the 24GHz spectrum that the FCC is planning to auction starting in March. First, the propagation characteristics of the two bands are very different: Transmissions in 3.5GHz will be able to travel much further geographically than transmissions in 24GHz; however, 24GHz signals will be able to transmit far more data.

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Further, the FCC is selling 24GHz spectrum licenses outright, meaning that companies that bid for and win 24GHz licenses will be the exclusive owners of that spectrum and will not have to be concerned about other operations interfering with their efforts in the band. The 3.5GHz band, meantime, is initially being released in an unlicensed scenario, meaning that anyone can make use of the band as long as they follow FCC emission guidelines. But, in a further wrinkle to the CBRS band, the FCC plans to hold auctions of CBRS licenses likely in 2020, potentially setting the stage for Cox and others to purchase exclusive use of portions of the 3.5GHz band.

Regardless, the developments help shed light on a privately held company that has mostly kept its strategic ambitions to itself. So far Cox has not indicated that it will follow its fellow cable providers into the wireless industry via an MVNO relationship. The market's three other major cable players have either already done so or are soon planning to do so soon -- Altice plans to launch Altice Mobile via an MVNO with Sprint sometime this year, while Comcast and Charter have already launched MVNOs via Verizon. These cable companies are entering the wireless space for several reasons, including to freshen flagging video businesses, to tighten their hold over their existing customers and to potentially attract new customers.

Cox is undoubtedly facing similar issues, but so far it has refrained from heading directly into the wireless market. But that's not to say that Cox is a stranger to the wireless business. For example, Sprint has an agreement with Cox whereby the cable company is installing small cells on its cable network that are essentially densifying and improving Sprint's mobile network.

And Cox at one time had major wireless ambitions: The company constructed a full-blown 3G network roughly a decade ago in its cable footprint, but by 2012 the company decided to shut down that entire network and discontinue its mobile services.

— Mike Dano, Editorial Director, 5G & Mobile Strategies, Light Reading | @mikeddano