Except for Cox Communications, all other major US cable operators plan to sit on the sidelines for the FCC's coming auction of 24 GHz and 28 GHz spectrum, a clear indication that many cable operators question the value and versatility of those millimeter wave bands for 5G services.

"Cable operators likely understand the limitations of milli-meter wave spectrum and the global attraction of using mid-band spectrum for 5G coverage," BTIG Research analyst Walter Piecyk said in emailed comments to Light Reading.

At this stage, there appears to be much more interest from cable operators in the 3.5 CBRS band, eyeing it as spectrum for a range of use cases ranging from MVNO offload and private LTE networks, with an eye toward 5G. The cable industry has also been urging the FCC to open up more spectrum for unlicensed WiFi use. (See Proposed CBRS Rules Suit Cable's Cause and Cable Makes Play for 5.9GHz Band .)

Cox Communications Inc. confirmed that it filed and completed the required application for the FCC's 24 GHz auction. But the MSO couldn't comment further, citing the Federal Communications Commission (FCC) 's auction rules.

The 28GHz auction (aka Auction 101) is set to start November 14; the 24 GHz auction (Auction 102) will be scheduled to start after the conclusion of bidding in Auction 101, according to the FCC.