Smarting under a $6 billion compensation claim from Oracle on Java patent violation lawsuit, Google has said Oracle's methodology for calculating damages is based on fundamental legal errors and that Oracle has improperly inflated their estimates.

The high-voltage dispute traces back to last August when Oracle sued Google, demanding the latter pay up for the use of Java in its Android operating system for smartphones and tablets. Google disputed the claims.

Oracle's lawsuit says Android operating system has infringed on Java copyrights that Oracle acquired when it bought Sun. If Google is found to infringe, it could be required to pay Oracle a licensing fee for each handset made that uses Android. It could pass that cost on to device vendors, but that would diminish the attractiveness of Android as a free operating system, Infoworld had reported earlier.

It had reported in January that according to an intellectual property expert, there have been at least 43 instances where Google apparently copied Java code without permission in the most recent versions of the Android operating system.

The discovery process could be very fruitful for Oracle, and may become dreadful for Google, the expert, Florian Mueller, was quoted.

Google's lawyer Scott Weingaertner says Oracle has followed a flawed method for arriving at the damages. The fact that Google does not charge for Android has muddled the situation. Google adds all of Google's revenue from advertising on all Android devices worldwide ... and then proposes awarding Oracle half of that amount, says Weingaertner.

According to Oracle's damages expert Iain Cockburn, Google would have to pay Oracle between $1.4 billion and $6.1 billion if Java patent infringement is proved. Google says Oracle is trying to finance the entire takevoer of Sun this way. Oracle acquired Sun last year for $7.4 billion.