BERLIN -- Ericsson, the market leader in mobile phone networking equipment, filed a lawsuit Tuesday against Samsung, the biggest smartphone maker, claiming that it had infringed on 24 of Ericsson's software and hardware patents.
The suit, filed in U.S. District Court in Tyler, Texas, was the second brought by Ericsson in six years against Samsung, which climbed atop the smartphone market largely by using Google's Android operating system, the most widely used operating system, instead of relying on its own.
Like most major mobile device companies, Samsung makes phones and tablet computers that use some hardware and software developed and patented by Ericsson. Kasim Alfalahi, Ericsson's chief intellectual property officer, said the lawsuit covered a broad range of patents involving GSM, GPRS, 3G and LTE mobile phone standards.
The lawsuit involves patents that are considered essential and part of broad mobile industry standards, as well as nonessential patents covering elements of a device's user interface, Mr. Alfalahi said. One involves the software technology Ericsson uses to translate speech into digital information and back again.
Ericsson's initial agreement for mobile patents with Samsung expired in 2011, Mr. Alfalahi said. The companies have since been negotiating, but to no avail.
The lawsuit, which asks for unspecified damages, is intended to raise the pressure on Samsung to negotiate. In its suit, Ericsson also alleged that Samsung, in a bid to compel Ericsson to lower its royalty demands, had refused to license Samsung's own industry-standard patents that are essential for modern mobile telephony.
Under law, holders of essential industry standard patents are supposed to license them on fair and reasonable terms to manufacturers, even competitors.
"We have more than 100 agreements with all of the major handset makers," Mr. Alfalahi said. "Our way is usually to try to avoid filing lawsuits. We are doing this only as a last resort."
Samsung said Ericsson was asking for a substantial increase in royalty payments and vowed to fight. It said it had been committed to "fair and reasonable" negotiations with Ericsson over the past two years.
"This time Ericsson has demanded significantly higher royalty rates for the same patent portfolio," Samsung said in a statement, which did not provide specifics on the royalties being discussed. "As we cannot accept such extreme demands, we will take all necessary legal measures to protect against Ericsson's excessive claims."
Mr. Alfalahi declined to say whether Ericsson had raised its royalty demands, or by how much.
As it has grown, the smartphone industry has become increasingly litigious as devices become ever more similar and market leaders, especially Apple, Google and Samsung, fight to protect the value of key innovations that give them a fleeting, yet profitable edge in sales.
"These types of lawsuits tend to come and go in cycles, and more often than not end in settlements," said Florian Müller, a patent consultant in Germering, Germany.
Patent infringement judgments tend to be much larger in U.S. courts than in Europe or Asia. In August, a jury in California ordered Samung to pay Apple $1 billion over patents for mobile devices.
While Ericsson has not been at the center of the recent wave of litigation -- Apple, Google, Samsung, Nokia and Research In Motion have been more active -- it has not been averse to going to court. It sued Samsung for the first time in 2006 alleging patent infringement involving mobile devices. The companies reached a settlement in July 2007, Mr. Alfalahi said.
Three of the 24 claims filed in Texas were also at issue in the earlier dispute, Mr. Müller said.
In April 2011, Ericsson sued ZTE, a Chinese cellphone maker, alleging similar infringement claims involving mobile software and hardware patents. The two companies settled the dispute later that year, Mr. Alfalahi said.
Ericsson filed its latest suit in U.S. court because the United States is the world's biggest intellectual property market, he said. Ericsson's U.S. subsidiary is based in Plano, Texas, near Dallas, and the company filed its first court challenge against Samsung in the same Texas court.
Samsung is currently involved in litigation with Apple in 10 countries.
"The Samsung-Apple fight is about who is No.1 and who is No.2 in the handset industry," Mr. Müller said. "The Ericsson-Samsung fight, I think, is more about Ericsson trying to maximize its revenue from intellectual property."
This article originally appeared in The New York Times.