Another patent battle between Motorola and Microsoft went before the International Trade Commission (ITC) today as Microsoft began arguing its case that Android-based smartphones made by Motorola Mobility infringed on seven of Microsoft’s patents.

Motorola Mobility is Google’s latest acquisition, and is the maker of some of the most popular and successful Android phones to date.  Microsoft is now alleging the infringement of seven of its patents, and is asking the International Trade Commission for an injunction on the importation of Droid 2, Droid X, Cliq XT, Devour, Backflip and Charm mobile devices to the U.S.

The case is the first smartphone dispute to be heard by the agency since Google announced  its plans to buy Motorola for $12.5 billion, a move done in order to obtain patents that could be used as a bulwark against a surge of lawsuits targeting handsets and tablet computers that use Google’s Android operating system.

Today’s suit from Microsoft has a provenance that precedes the existence of Motorola Mobility as a separate entity.  Microsoft first launched a roundabout Android attack via a Motorola patent suit back in the fall of 2010.  At that time, Microsoft’s deputy general counsel Horacio Gutierrez said the patents relate to features and functions in Motorola’s Android phones that were “essential to the smartphone user experience.” The specific features included scheduling meetings, maintaining calendars and contacts, synchronizing email, and reporting battery life and signal strength changes.  Around the same time, Microsoft also sued Motorola for inflating royalties for some of its Xbox-related technologies.

Moreover, Microsoft fires a legal shot over Motorola’s bow and asks the ITC to ban handset imports into the US.   According to Bloomberg, Microsoft is “confident that the ITC will rule in [its] favor.” Meanwhile, Motorola spokeswoman Jennifer Erickson said in an email to Bloomberg that Motorola is “vigorously defending [itself] against Microsoft’s patent attack business strategy.” And a business strategy is exactly what it is.

However, Android smartphone market share rise up to 52 percent in second quarter while Motorola declines market according to a recent NPD report.  Its report emphasized that Google could play a big role in “revitalizing” the ailing Motorola, whose market share dropped from 15 percent to 12 percent in Q2.

Motorola has also lost over half of their share in the Android OS market, going from 44 percent in 2010 down to 22 percent in 2011 thanks to Samsung and HTC, who have effectively taken that market share.

Ross Rubin, NPD’s executive director on industry analysis, claims that, “much as it did in the feature phone market in the RAZR era, Motorola is experiencing increased competition from Samsung and LG in the smartphone market.” He added that “closer ties to the heart of Android can help inspire new paths to differentiation.”