Just when it appeared Qualcomm finally had a fight on its hands after winning one round last month against Nokia, a judge has invalidated a good chunk of Qualcomm's original injunction request against the handset maker.

In an initial determination handed down yesterday, a US International Trade Commission judge has denied Qualcomm's request for an injunction against the import of Nokia's GSM and EDGE handsets into the US, on the grounds that they infringed upon three of Qualcomm's patents. In so doing, Judge Paul J. Luckern declared one of the three patents in question invalid.

The basis of that invalidity claim, the judge determined, was the portion of US Code recently strengthened by a Supreme Court decision: Specifically, it's the part that says if a previous invention makes the need for the new one obvious to just anyone, it's not a patentable idea.

35 U.S.C. 103 designates that a patent may not be obtained "if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains."

The patent in question, a USITC spokesperson confirmed for BetaNews, is #5,452,473, "Reverse link, transmit power correction and limitation in a radiotelephone system." The patent applies to both FDMA and CDMA cell phones, and relates to a way in which a handset can avoid elevating its own power emissions to the point where it interferes with its own 800 MHz network. So it's a way of detecting how much power a handset is emanating based on the frequency its own output is generating, and correcting those emissions using a table of corrective measures that apply to different detected frequencies.

On the surface, that doesn't seem like an obvious invention. But the sealed portion of the judge's ruling -- the part which the public is not allowed to see in order to protect trade secrets -- may have handed Qualcomm a loss on its own account: Another invention to which the '473 patent directly refers, and which is attributed to Qualcomm, may have been the invention that made the power corrector too obviously necessary.

This latest ruling may balance the stakes between the two warring companies, after a different USITC judge threw out some of Nokia's claims against Qualcomm last month.

"The judge's initial determination is subject to review and possible modification by the Commission," a USITC spokesperson told BetaNews this afternoon. "The target date by which the Commission must complete its action in this case is April 14, 2008."