Sprint Sues Four Cable Giants Over Voice Patents

With
Sprint’s legal battle against AT&T’s merger with T-Mobile effectively at an end, the operator is turning its attention to cable operators.

Sprint
is suing Comcast, Time Warner Cable, Cox Communications and Cable One for
violating its patents on technology that routes voice calls over a packet-based
network instead of expensive public landline networks.

The
complaints were filed separately Monday in the U.S. District Court in Kansas
City, Ka., Sprint’s home state.

The
suits allege that the four cable operators are infringing on 12 of Sprint’s
patents on its voice-over-packet technology. Sprint says late employee Joe Christie
developed a way to leverage packet-based networks for voice calls in the
1990’s, helping to build a portfolio of more than 120 issued U.S. patents on
the technology.

“Unfortunately,
many companies in the industry… have realized the great value in this
technology and have misappropriated it without
Sprint’s permission,” Sprint said in its complaint.

Sprint
is asking for unspecified damages and wants the court to ban the cable
companies from selling services it says violate its intellectual property
rights, including Time Warner’s Digital Home Phone and Comcast’s XFinity Voice.

The
cable companies named in the complaint could not be immediately reached for
comment.

The
patents at question in Sprint’s latest suit were the subject of a 2007 complaint
against Vonage. Sprint won that case after the jury found that Vonage had
violated six of its patents on the voice technology and awarded Sprint $69.5
million in damages. Vonage later paid Sprint $80 million to license its
portfolio of voice-over-packet patents.

Sprint
has successfully sued a number of other companies over the patents, and has
reached settlements with Paetec, Broadvox, Big River Telephone and Nuvox. A
number of other unnamed companies also license Sprint’s voice-over-packet
patents.