The nation's top two carriers — Verizon and AT&T — are keen to remind federal regulators of their spectrum constraints at every opportunity. To that end, Verizon took to a joint filing to the FCC with SpectrumCo last Friday in defense of their proposed sale of AWS spectrum, a transaction that T-Mobile has publicly opposed. In the filing, Verizon goes over why and how its existing 700MHz LTE deployment will be out of breathing room "in some areas" by next year with wider-scale exhaustion by 2015; it says that it'll be able to alleviate a bit of the strain through future LTE femtocell rollouts and "piecemeal" refarming of existing CDMA 1x spectrum, but that neither technique will be sufficient to meet the need.

As with many FCC filings, Verizon's is of limited use to the public because much of it is redacted — hard numbers about the carrier's existing deployment and plans for expansion are intentionally left out, which makes it unclear just how the 2013 timeline is being arrived upon. Also unclear is why Verizon continues to offer a double data promotion on 4G data plans when it allegedly knows of an impending exhaustion. Of course, Verizon intends to use these AWS acquisitions for LTE deployment — hence the doomsday language in the filing — but T-Mobile has already made clear that it won't let the deal slide past regulatory approval without a challenge.