Net refers to the three major networks of Telecom Network, Radio and Television Network and the Internet. The three networks are the existing, independent, independent traditional telecommunications networks, computer broadband networks, and limited television networks to achieve mutual penetration and unity. In the end, a variety of services are used in an independent network. The physical link is presented to the information consumption side. Therefore, the three networks and one network system have the following characteristics:

(1) Users only need a physical network connection to enjoy other network resources or communicate with users on other networks.

(2) The network is interoperable in the physical layer, which means that the signal of a network can be transmitted directly or through tissue or transformation, and it is transmitted to another network. When transmitting to the user terminal through another network, the information does not change the information. The content, that is, the network should be transparent.

(3) The business between the network penetrates and cross the application layer, but they can be independent and unhindered by each other, and they can develop their own new businesses independently on their respective networks.

(4) The agreement between the network is compatible or can be converted. This is because each network has its own protocol, so when the information is transmitted from one network to another, it should meet the requirements for the transition network.