What Is Noncommercial Satellite Radio Programming?

The XM-Sirius merger took another step towards actually happening today, when FCC Chairman Kevin Martin said he'd support it. The AP reports:

The deal affects millions of subscribers who pay to hear music, news, sports and talk programming, largely free from advertising, in homes and vehicles...
The thorniest part of the negotiations was over how much radio spectrum the companies would turn over to noncommercial and minority broadcasters.

"Noncommercial", in this context, clearly doesn't mean advertising-free, since that would apply to nearly all of the programming. And it doesn't mean programming which is available without a subscription, either: you'll need to pay to listen to anything on satellite radio. It doesn't even mean diverse programming: the whole satellite radio business model is based on the idea of providing a vast range of options to subscribers, thereby maximizing the number of people you're potentially appealing to.

Alex Kanous explains that "noncommercial", in this context, means something between high-minded and low-impact:

Public Knowledge has insisted that the proposed merger be conditioned on the new company providing 5% of their spectrum capacity to non-commercial programmers, like public educational broadcasters, non-profit educational institutions, and local low-power radio stations.

There's something slightly absurd about the idea of taking a local low-power radio station and broadcasting it nationally: either no one would listen to it on satellite and there would be no point to the exercise, or else people would listen to it on satellite and the station would cease to be either local or low-power.

As for the educational broadcasters, does that mean student radio? I'm sure neither Sirius nor XM would mind having a few student radio stations on their list, given the millions of people who listen to student radio nationwide; I can't imagine that negotiations there would be particularly thorny. On the other hand, if it's some kind of course-specific programming that Kanous has in mind, one does have to wonder just how much benefit it would have, given the fact that you need to pay for a satellite radio subscription in order to listen to it, and given the fact that there's going to be a finite number of these stations.

My suspicion is that the whole debate over noncommercial programming is really a fig-leaf for the FCC to use in order to justify allowing the merger to go through. But that wouldn't explain why it became such a thorny part of the negotiations. So what's really going on here?