Dish Network is turning to patent litigation in its fight with Univision, as the companies’ distribution standoff continues with no end in sight after a nearly seven-month blackout.

Dish — well known in the pay-TV biz for its litigious and hardball negotiating tactics — filed a federal lawsuit against Univision on Jan. 25. The suit alleges that the Hispanic broadcaster’s products including subscription-streaming service Univision Now, the Univision app, and Univision Deportes services violate four Dish-owned patents covering adaptive bit-rate streaming.

According to Dish, the company has issued licensing requests to and initiated legal action against multiple streaming services, not just Univision. “Dish is seeking to enforce its patents related to HTTP-based adaptive bit-rate streaming technology that enables content delivery to adapt to the bandwidth available at any particular time, ensuring the highest possible quality content for the available bandwidth throughout the course of the stream,” a Dish rep said in a statement.

Dish notified Univision of the patent claims in July 2018, shortly after the programmer’s channels went dark. In August, Univision sent a response to Dish asserting that it was not infringing the patents.

“As we previously informed Dish, we deny that we are in violation of any of its patents. As such, we intend to vigorously defend ourselves against these claims,” a Univision rep said in a statement.

Univision programming was pulled from Dish Network and its Sling TV over-the-top service on June 30, 2018. Dish told investors that the removal of Univision’s channels “could become permanent.” With the blackout, Dish has urged customers to access Univision using over-the-air antennas. “We prefer that our customers pay for Univision,” Dish chairman Charlie Ergen said on the company’s Q3 earnings call. “But to the extent [Univision doesn’t] want to have a contract with us… we know that in the urban markets where most of our Latino customers are, [over-the-air antenna] is a very attractive alternative.”

Dish execs admitted that the Univision blackout contributed about half of its TV subscriber losses for the third quarter of 2018, when the provider posted its biggest quarterly net subscriber loss to date with a drop of 367,000 satellite TV customers and a gain of only 26,000 Sling TV subs. Dish also is in a contract fight with HBO, which has been unavailable on Dish satellite and Sling TV services since Oct. 31.

Dish’s lawsuit seeks a permanent injunction barring Univision from using the patents, as well as unspecified monetary damages. The complaint, filed in the U.S. District Court for the District of Delaware, assigned docket no. 1:2019-cv-00144. The original owner of the four patents cited in Dish’s lawsuit was Move Networks, an adaptive bit-rate streaming technology startup that Dish’s EchoStar acquired in 2011 for $45 million.

The patent lawsuit gambit comes after previous legal maneuvering on both sides. Dish sued Univision for distributing games from Mexico’s Liga MX for free in English on Facebook. Univision countered with a still-pending lawsuit against Dish in October, alleging that Dish owes its millions of dollars in past licensing fees and accusing Dish of trademark infringement and false advertising by claiming Univision was still available on its services.