The British phone company says, in its US-filed lawsuit, that Google has infringed on these patents in the Android operating system, apps on the Android Market, Google Maps, Docs, Music and Offers, various location-based services and most of its advertising empire.

An example patent is “Service provision system for communications networks,” which BT was awarded in the 1990s. It essentially boils down to an app figuring out whether a phone is connected to the web via Wi-Fi or 3G, and choosing to stream at a different bandwidth. Google infringes this in Google Music and the Android Market, BT alleges.

The other patents cover navigation systems (Google Maps is the culprit here), location-based information (infringed just about everywhere) and digital rights management (Android Market is fingered).

If BT is successful in court it could force Google and Android handset makers to pay royalties on each Android handset that’s in use. That’s a lot of devices — this summer, Google Mobile president Andy Rubin took to Twitter to announce that “there are now over 500,000 Android devices activated every day.”

BT joins a pantheon of disgruntled patent-holders, who are all fighting similar legal battles against Google. In terms of large publicly-traded companies, Apple, Oracle, Microsoft, Gemalto and eBay are all at the search titan’s throat.

Microsoft and Samsung reached a deal earlier this year, where Microsoft will receive royalties for every Android smartphone that Samsung sells. Following similar deals with HTC, Acer and various other manufacturers, Microsoft now gets paid for almost every Android phone and tablet that’s ever sold.

Spurred on by its need to defend itself in this hotly-contested market, Google made a $12.5 billion acquisition of Motorola Mobility in August — a move that would, in its own words, “strengthen Google’s patent portfolio, which will enable us to better protect Android from anti-competitive threats from Microsoft, Apple and other companies.”

In a statement, passed to Wired.co.uk, a Google spokesperson said of BT’s lawsuit: “We believe these claims are groundless and we will vigorously defend ourselves against them.”

Originally published by Wired.Co.UK