Google has been working to augment its defensive patent portfolio with the intent of deflecting the litigation that has targeted its embattled Android mobile operating system. To this end, the company purchased over a thousand patents from IBM in a major deal last year. The search giant followed that up with a smaller deal this week, in which it has purchased approximately 200 patents and pending patent applications.

The Android platform has faced a barrage of attacks from patent trolls and rival players in the smartphone market. Some of those attacks have targeted Android hardware partners, such as HTC; Google gave that company a handful of patents from the previous IBM deal in order to help the company bolster its defenses. In addition to fending off threats from rivals, Google is also battling Oracle, which contends that Android's custom Java runtime environment and compiler both infringe on Java-related patents.

Google has historically had little interest in patents, but has been forced to spend billions of dollars accumulating a robust defensive portfolio over the past year due to the treacherous litigation landscape that plagues the smartphone industry. The most notable development in this regard was Google's $12.5 billion bid to acquire Motorola, a purchase that could net Google an additional 17,000 patents. The acquisition of Motorola is still pending and expected to complete this year, but met some delays during the regulatory approval process.

Oracle's dispute with Google is heading for a jury trial in March, according to a pretrial order filed Wednesday by Judge William Alsup, who has been hearing the case. Alsup expressed frustration with both parties over their unrealistic damages estimates, which suggests the trial could be long and contentious.