updated 05:50 pm EST, Tue December 20, 2011
Claims infringement on 12 VoIP patents
Sprint has filed lawsuits Monday against Time Warner, Comcast, Cox, and Cable One. The complaints against the four were filed separately in a Kansas City federal court. The US' third largest wireless carrier alleges that each cable provider infringed on 12 patents that it holds for digital voice calls sent over landlines.
Sprint's patents center around sending voice calls as packetized digital information over data networks instead of the traditional circuit based PSTN networks operated by long distance and local voice carriers. The technology has evolved to what is now referred to as VoIP (Voice over IP). Sprint's patents also covered the transfer of the voice calls between the data and voice networks.
Sprint claims that the voice-over-cable plans each of the four companies uses are violating the patents.
This was not the first time that Sprint has pursued providers using VoIP technology. In 2007, the carrier won a $84 million judgement against Vonage. The patents infringed upon were a subset of the 12 patents involved in the current cases.
All four cable companies have indicated that they won't comment on pending lawsuits. The Vonage precedent might push them to settle rather than risk the costs of a trial and the risk of a ban.