Ericsson has launched a countersuit against Apple, just days after the iPhone-maker filed a lawsuit against the Swedish telecoms equipment manufacturer in a dispute over royalty payments for patents.
On Wednesday, Ericsson filed its complaint in the United States District Court for the Eastern District of Texas regarding whether Apple's global licensing offer for use of Ericsson technology was "fair, reasonable, and non-discriminatory".
In a statement, Ericsson said that Apple's license to use its high-speed wireless technology has expired, and that no new agreement has been reached despite two years of negotiations.
"Our goal is to reach a mutually beneficial resolution with Apple. They have been a valued partner for years and we hope to continue that partnership," Kasim Alfalahi, chief intellectual property officer at Ericsson, said in a press release.
The technology concerned is used in Apple's phones and tablets. It is known as "Long Term Evolution" or LTE technology and is used for 4G mobile internet.
, which claimed that Ericsson was demanding excessive royalties for its LTE patents. Apple also said that the patents concerns were inessential for meeting cellular industry standards for this high-speed mobile internet.
Apple denies infringing Ericsson's patents, but asked that if the court found that an infringement had occurred, that subsequent royalty payments be "reasonable". The Cupertino, CA-based technology giant's lawsuit was filed in the U.S. District Court for Northern California on Monday.
Patent infringement cases are not unusual in the mobile industry. A court ordered Chinese smartphone maker Xiaomi to stop selling phones in India last month, after Ericsson accused it of infringing patents.
And In 2011, Apple agreed to pay Finnish telecoms equipment maker Nokia an undisclosed fee over a patent dispute.