AT&T Co has been ordered to pay Collins Licensing $34.6m following a patent infringement suit against it over its 5ESS digital telephone exchange. A Federal District Court jury in Midland, Texas, held that AT&T’s 5ESS digital telephone exchange products infringe Collins’ US Patent No 3,956,593 Time Space Time Switch With Combined and Distributed State Store and Control Store, issued May 11, 1976: it covers a switch using to basic modules, a time switching module and a space switching module. Collins Licensing Ltd Partnership is the owner of digital transmission and switching patents awarded to Arthur A Collins Inc. The late Arthur Collins was the founder of Collins Radio Co, now Collins Division of Rockwell International. The attorney for Collins Licensing, Joseph Grear of Rolf Stadheim Ltd, said that he was pleased with the findings of the jury since Arthur Collins was a pioneer in the field of digital telecommunications. AT&T has said already that it intends to fight the ruling, and it maintains that there was no patent infringement. Collins Licensing is now pursuing claims against L M Ericsson Telefon AB, Siemens-Stromberg Carlson Inc and Northern Telecom Ltd over the same patent: all three claim that they developed the digital switching technology they use independently.
