First, the network is uniform and ubiquitous. It links to and is compatible with mobile networks. The many kinds of networks need to become one -- distributed and point-to-point Local Area networks, private and public Wide Area Networks, proprietary terminal and cluster interconnects and protocols, and Plain Old Telephone Service, including the telephony switching fabric.
If this isn't enough, then the cable networks using broadband, broadcast technology would also adopt ATM and inter-operate with the phone and data networks. However, let me not predicate the network on having to carry switched television, although in principle it could and may. Replacing the cable and broadcast television network is a question of plant and equipment investment, and government regulation.