Yes, Virginia, narrowbanding is real, and you better be operating on 12.5 kHz channels by Jan. 1, 2013.

That was the main point in the much-anticipated FCC public notice issued last week to clarify many rules around narrowbanding radio systems operating between 150 MHz and 512 MHz. Those who don’t meet the narrowband deadline should expect enforcement action, although the agency stopped short of specifying which level of enforcement — admonishment, fines or license suspension — it would use.

The bottom line is that narrowbanding is a mandate, not an option. There’s no alternative such as operating on a secondary basis; if you are operating a radio system in the affected bands that uses 25 kHz channels, you are in violation of the FCC’s rules and will face consequences.

This clear line in the sand should be helpful as communications directors try to convince their elected governing bodies — city councils, county commissions or state governments — that they need money to narrowband their systems. Almost certainly, there will be grumbling about “unfunded federal mandates,” but these elected officials should recognize that narrowbanding is something that simply has to be done, even if it’s tough to find additional money in this economy.

In addition, the fact that the FCC said it would allow current radios that have 25 kHz and 12.5 kHz modes in them to be manufactured and imported beyond 2011 — if the 25 kHz mode can be disabled via software — should be welcome news to vendors, because they won’t have to the process of essentially recertifying a bunch of existing products.

But big questions remain, most notably those brought up in the petition filed by the National Public Safety Telecommunications Council (NPSTC) asking that the FCC stay the requirement in 2011 for newly certified radios to include a 6.25 kHz channel equivalency mode, even though no standard for that channel size exists today.

To be fair, the FCC only closed the reply-comment period on the NPSTC petition less than two weeks ago, so a public notice addressing those issues could hardly be expected now. However, hopefully, the commission will address the NPSTC issues quickly, because operators and vendors both need answers quickly, so they can make the most cost-efficient business decisions possible.

But no matter what decisions the FCC makes on the NPSTC petition, the big unknown is what exactly will happen in the marketplace. Narrowbanding is not required until 2013, but no new 25 kHz products can be manufactured after 2011. What happens during the two years between 2011 and 2013 could be very intriguing.

Licensees that don’t plan to narrowband until late 2012 may feel the need to stockpile 25 kHz-capable radios, so they are assured of having replacement radios in case a radio stops working. Similarly, vendors will have to estimate how many 25 kHz-capable radios they should inventory to meet such potential demand — such radios may be sold after 2011, just not manufactured or imported.

Meanwhile, there has long been speculation in the industry that a “black market” for 25 kHz-capable radios might evolve as the licensees’ and vendors’ stockpiles of the equipment dwindle. The idea of public-safety entities buying equipment under such circumstances — presumably without warranties — is hard to imagine, but if that’s the only way to get a radio that works on a system, such entities may not have much choice.

Such talk makes for interesting conversation, but my hunch is that this concern may not be any greater than the year 2000 problems the computer industry feared a decade ago. Hopefully, vendors and licensees will be able to estimate the need for 25 kHz-capable gear accurately enough that there is not a dire circumstance for any system from 2011 to 2013, while waiting to make the transition to 12.5 kHz equivalency — and if such scenarios arise, the FCC will grant vendors the flexibility to address the situations.