Furukawa Electric North America APD Inc. of Plymouth, Mich., and its subsidiary, OFS Fitel LLC of Norcross, Ga., have filed a complaint against Yangtze Optical Fibre and Cable Co. Ltd. in the US District Court for the District of Massachusetts. The companies allege that the Wuhan, China, business has infringed on several US patents. An investor in research and development with its own intellectual property portfolio, Yangtze Optical intends to defend the lawsuit.