Free for a Fee

A patent war between AT&T and Cox Communications over TV and DVR technology escalated significantly this week, as Cox filed a lawsuit (PDF) against AT&T in Atlanta federal court.

AT&T sued Cox in August, and the strategy of filing a “countersuit” like the case Cox filed earlier this week is a common one in patent litigation.

Cox’s counterattack involves US patent nos. 7,992,172, 8,332,889, and 5,999,970. The first two were filed by Cox in 2000 and 2007, respectively, while the ‘970 patent belonged to a now-defunct Pennsylvania company called Worldgate Communications.