US Patent 12132672 Time alignment timer information

A base station distributed unit may transmit a timing advance command for a timing advance group to a wireless device. The base station distributed unit may start a time alignment timer for the timing advance group of the wireless device in response to the transmission of the timing advance command. The base station distributed unit may determine expiration of the time alignment timer. The base station distributed unit may transmit a first message to a base station central unit. The first message may indicate the expiration of the time alignment timer for the timing advance group of the wireless device.