With a little more than a day before the iPhone 5’s expected debut, Samsung has decided to sue Apple for patent infringement over its reported use of long-term evolution (LTE) connectivity in the next-generation smartphones.

Expected to be unveiled at a press event in San Francisco on Wednesday, the iPhone 5 will reportedly feature the speedier fourth-generation wireless networking, for which Samsung holds numerous patents. Samsung, which has been locked in a series of high-stakes patent trials with Apple, had previously threatened to sue the iPhone maker if it were to release LTE-enabled products.

After Monday’s reports of LTE capability on the iPhone 5, the South Korean electronics giant “has decided to take immediate legal action,” an industry source tells the Korea Times. Europe and the United States “are our primary targets,” the source said.