Enlarge / T-Mobile advertisement in New York City's Times Square on October 15, 2020. (credit: Getty Images | SOPA Images) The Federal Communications Commission has finished investigating T-Mobile for a network outage that Chairman Ajit Pai called "unacceptable." But instead of punishing the mobile carrier, the FCC is merely issuing a public notice to "remind" phone companies of "industry-accepted best practices" that could have prevented the T-Mobile outage. After the 12-hour nationwide outage on June 15 disrupted texting and calling services, including 911 emergency calls, Pai wrote that "the T-Mobile network outage is unacceptable" and that "the FCC is launching an investigation.