The Department of Justice sued to block the AT&T/T-Mobile merger in late August on the grounds that it was anticompetitive. Sprint and C Spire, formerly know as Cellular South, filed their own suits shortly thereafter.

The two rival carriers have requested that the judge add their cases to the DOJ's suit, but that issue has not yet been decided. Instead, today's proceedings will address a September request from AT&T that the cases be tossed. The burden is on Sprint and C Spire, which have to adequately prove that their businesses would be hurt by a combined AT&T and T-Mobile.

It's not clear if U.S. District Judge Ellen Segal Huvelle will actually issue a ruling today. There are several possible scenarios: she could listen to the case and say nothing; ask a lot of questions but not issue a ruling; or rule from the bench.

Judge Huvelle will also consider a rather procedural matter this afternoon. Essentially, during the discovery process, the Department of Justice gathered some rather sensitive information from various tech firms in order to make its case. That information was made available to AT&T lawyers on a limited basis via a protective order, but Sprint and C Spire do not have access. Both carriers have requested access to the data, and the judge will hear arguments on that today.

The hearing kicks off at 2:30pm in Washington, D.C. today, so stay tuned for any news in the early evening.

The case is scheduled to go to trial on February 13.