Cingular Wireless has been named as a defendant in a patent infringement lawsuit centering on ringback tones that was filed by Ring Plus.

Representatives from Ring Plus did not return calls seeking additional details on the patent infringement claim, but in a press release the company said the suit covered ringback tone patent infringement. The suit was filed in a U.S. federal court.

Cingular was unfamiliar with the lawsuit. "I have not seen the suit, so it would be inappropriate for us to comment on it," according to Cingular spokesman Mark Siegel.

Cingular offers its Answer Tones ringback tone service for a monthly subscription fee of 99 cents. Individual Answer Tones can be purchased for $1.99. The carrier launched the service i...
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