Microsoft has filed a patent infringement lawsuit against Motorola, accusing it of using its technology in Android phones.
Microsoft says the infringements cover nine different features and functions including contacts, calendar, email synchronisation, scheduling meetings and notofication of changes in signal strength and battery power.
It says that Motorola licensed the technology between 2003 and 2007, but has continued to use it since.
"We have a responsibility to our customers, partners, and shareholders to safeguard the billions of dollars we invest each year in bringing innovative software products and services to market," says Horacio Gutierrez, corporate vice president and deputy general counsel of Intellectual Property and Licensing.
"Motorola needs to stop its infringement of our patented inventions in its Android smartphones."
Microsoft has filed a lawsuit in the US District Court for the Western District of Washington, as well as a patent infringement claim with the International Trade Commission.
"The Microsoft innovations at issue in this case help make smartphones 'smart'. Indeed, our patents relate to key features that users have come to expect from every smartphone," says Gutierrez.
"That Microsoft has important patents in this area should not surprise anyone – we’ve spent over 30 years developing cutting-edge computer software... Our action today merely seeks to ensure respect for our intellectual property rights infringed by Android devices; and judging by the recent actions by Apple and Oracle, we are not alone in this respect."
A decision in Microsoft's favor would, to say the least, be a bit of a blow for Android, as one of its main advantages is its open source nature, which has helped keep the price of Android phones down.
And Microsoft's obviously picked its timing with some care, as it now looks likely to release Windows Phone 7 handsets in about a week's time.