So far one of the biggest problems for a federal judge overseeing a patent battle between the world’s largest smartphone makers isn’t about stolen ideas. It’s getting the roomful of smartphone devotees to turn off their devices.

U.S. District Judge Lucy Koh has become increasingly frustrated during the first few days of the trial pitting Apple against Samsung because the many personal Wi-Fi signals interfere with a network the judge relies on for a real-time transcript of the proceedings.