AT&T is seeking regulatory approval to shut down its old-school (and, well, just old) copper networks. In a letter that the carrier wrote to the FCC at the start of this month, AT&T submitted to the agency its application to grandfather and shut down a legacy TDM (Time Division Multiplexing) based voice service in Oklahoma. AT&T wants to grandfather the network on December 15, 2024 and shut it for good on September 15, 2025.