The prospect of a ban on imports of components for BlackBerrys and other 3G phones began all over again on Tuesday, as chip manufacturers Qualcomm and Broadcom entered an appeals court to replenish their long-standing patent battle.

Qualcomm will now try to convince a US Court of Appeals that imported Qualcomm chipsets, to be used in some high-end cell phones, do not constitute infringement of Broadcom patents. Back in June of 2007, the US District Court in Santa Ana, CA found otherwise, citing violations by Qualcomm around a total of three patents.

Spurred in part by that judgment, the US International Trade Commission (USITC) then issued an exclusion order the following month banning the import of infringing chipsets, along with some cell phones and PDAs containing Qualcomm's silicon.

On its own, the USITC had previously found violations by Qualcomm, too -- but affecting only one Broadcom patent, as opposed to three. "The patent relates to mobile device capabilities and power management," the Commission said in a statement issued to announce the ban.

"The chips and chipsets at issue are used in handheld wireless communications devices, including cellular telephone handsets, that are capable of operating on so-called third-generation ("3G") cellular telephone networks, i.e., EV-DO ("Evolution-Data Optimized") and WCDMA ("Wideband Code Division Multiple Access") networks such as those operated by Verizon, Sprint, and AT&T," according to the USITC.

The Commission's exclusion order, however, was ultimately rescinded at the behest of Ken Starr, former US Solicitor General, now working on behalf of three major wireless service providers and a number of large cell phone/PDA manufacturers.

The companies included AT&T; Sprint Nextel; T-Mobile; BlackBerry maker Research in Motion (RIM); Motorola; Samsung; Kyocera Wireless; LG Electronics; and Palm.

In the US District Court decision reached in May 2007, a nine-person jury found Qualcomm guilty of infringing these three US patents: No. 5,657,317, "which relates generally to simultaneous participation on two networks from a single transceiver;" No. 6,847,686, "which relates generally to a chip architecture for performing video processing;" and No. 6,389,010, "which relates generally to a phone that may be used to place calls over fixed or variable bandwidth networks."

More specifically, the jury found that Qualcomm had used Broadcom's video chip architecture for providing improved video performance in its Enhanced Multimedia and Convergence chip platforms, and also that Qualcomm had violated Broadcomm's '010 patent with the "push-to-talk" feature in its QChat software.

Following a 13-day trial, the District Court in Santa Ana also awarded Broadcom $19.64 million in damages.

In an effort mounted by Qualcomm, the Appeals Court will now revisit the contentions of both Broadcom and Qualcomm in the civil suit.

Either way the appeals court rules, though, it will still be up to the USITC to reinstate the exclusion on the imported chips and cell phones -- if that, in fact, is ever going to happen.