The new operators may be moving rapidly, but AT&T is the poster child for an old-school telco which has seized the opportunity of transforming itself with digital, cloud and virtualization technologies. This long and challenging process should, it hopes, greatly enhance the range and value of services with which to ensure return on its 5G and fiber investments. As part of its transformation process, it has shaken up its supply chain and introduced new vendors alongside its traditional partners. The latest new partner is cloud platform provider Mirantis, which has won a three-year deal to help the telco build out the next generation of its Network Cloud, this one focused on 5G. AT&T has been building this Network Cloud using…