The smartphone industry is in an arms race for patents that is hurting consumers and leaving Google to "sort through the mess" of litigation, says the company's general counsel Kent Walker.

"It's hard to find what's the best path - there's so much litigation," Walker said.

"We're exploring a variety of different things."

Google, whose Android mobile operating system has been targeted in at least six legal complaints, is seeking to buy intellectual property that could be used as a defence against litigation.

Google, the world's largest internet search company, is also seeking to curb abuses of the system, calling on Congress and the Federal Trade Commission to rein in lawsuits, and asking the US Patent and Trademark Office to take closer looks at patents being used in litigation, Walker said.

"The tech industry has a significant problem," he said. "Software patents are kind of gumming up the works of innovation."

Google's competitors have said the California-based company is critical of the patent system because it has few patents of its own and entered a smartphone market where companies had been researching and selling products for years before Android phones went on sale in 2008.

Google has been assigned 728 patents so far, according to the US Patent and Trademark Office database, mostly for search engine technology.

Apple has more than 4000 US patents, and Microsoft more than 18,000, according to the database. Patents give their owners a right to exclude others from using the invention for a set period of time.

"It is about innovation and competition," said Will Stofega, a program manager at researcher IDC.

"Doing basic research to bring new products to market is something quite distinct from their core capabilities."

The Android system is a free, open-source program that relies on some nonproprietary features Google didn't create and allows outside developers to modify the code.

That has left the company vulnerable to claims that it built Android on the backs of research done by other technology companies.

"A patent is a patent and you may not agree with it, but it's the law," Stofega said. "It's a weakness for Google and everyone's acknowledged it. The competition is so fierce and so brutal, any perceived weakness is going to be found out and you're going to pay for it, in court or wherever."

Android is the most widely used mobile operating system for smartphones, with 38.9 per cent of the worldwide market, compared with 18.2 per cent for Apple's iPhone, according to IDC.

Oracle, the world's largest supplier of database software, contends Android uses its Java programming language, in violation of patents and copyrights.

California-based Oracle sued, seeking as much as US$6.1 billion ($6.9 billion) in damages, after Google baulked at paying US$100 million for a licence to use the technology.

In ruling last week on what type of damages should be considered, US District Judge William Alsup said: "Google may have simply been brazen, preferring to roll the dice on possible litigation rather than to pay a fair price."

Alsup said US$6.1 billion in damages was too high a price for consideration based on facts of the case and set US$100 million as the starting point for discussion of damages.

Walker said Google maintains that the patents are invalid and not infringed.

Apple has patent cases before the US International Trade Commission that target Android phones made by Samsung Electronics, HTC and Motorola Mobility Holdings. Each of those companies has filed cases against Apple. Microsoft and Motorola Mobility also have patent suits against each other, and Microsoft has a pending ITC complaint against Barnes & Noble over the Android-based Nook reader.

Google has few of its own patents, while Samsung and Motorola Mobility have been able to use their patents to lodge infringement claims against Apple and Microsoft.

Walker said it's "crazy" that both HTC and Apple phones could be barred from the US market if a deal isn't reached.

"Each side can blow the other up on some level - everybody can block the other's products from coming to market," Walker said.

"You create this mutually assured destruction scenario, but it's very expensive to get all those munitions."

Google has been hesitant to use patents to file suits against other companies, he said.

"Buying patents so you can hit the other guy, it's not good form," Walker said.

The company is providing support and technical help to companies that make products for Android and are being sued, either by rival companies such as Apple and Microsoft, or by small patent owners that don't make products.

"We'll be fine," Walker said. "We have the resources to balance the scales here."

- Bloomberg