US Supreme Court has ordered a retrial.
The US Supreme Court has ruled against Cisco Systems over its patent infringement case with Commil USA.
The case revolves around a patent held by Commil on a method to enhance the implementation of a wireless network with various access points.
In a 6-2 decision, the supreme court rejected a June 2013 ruling by the US Court of Appeals for the Federal Circuit in favour of Cisco.
This appeal was based on an April 2011 ruling which awarded Commil almost $63.8 million in damages. follwed an initialwhich awarded Commil a $63.8m judgment against Cisco.
The court has now ordered a new trial into the case.
Ruling out Cisco’s defence, the Supreme Court said: "The question the Court confronts today concerns whether a defendant’s belief regarding patent validity is a defense to a claim of induced infringement. It is not."
According to the ruling, "An accused infringer can, of course, attempt to prove that the patent in suit is invalid; if the patent is indeed invalid, and shown to be so under proper procedures, there is no liability.
"That is because invalidity is not a defence to infringement, it is a defence to liability."
One of the attorneys from Sayles Werbner, which represented Commil, said: "Today’s ruling means Cisco and other companies can’t avoid infringement liability simply by arguing that they didn’t think a patent was valid."
A Cisco spokesperson said: "The federal circuit’s ruling vacating the jury verdict in this case still stands.
"Today’s decision simply eliminates one of many strong defenses available to Cisco and we look forward to the retrial of the case."