Thanks to the advanced science and technology, modern information sector, or specifically the internet, has transformed the huge global into a small “global village”. Network information technology emerge itself in the limelight of the public. As the modern information technology progresses, the traditional voice and video services find themselves incompetent to fulfill the demand of people. And the network has come a long way in the comprehensive application of multimedia technologies, such as data, graphics, audio, video. Although traditional telephone networks, cable television networks and computer networks have their own strengths in network resources, information resources and access technologies, they all specialize on certain business: telecommunication network is voice-oriented; TV network is video-centered; computer network is data-focused. Users can only obtain all kinds of services from different service providers, and at the same time, the network resources will overlap just because of the absence of intercommunication between different networks. Against such context, the conception of "three networks in one" is put forward.
The so-called "three networks in one" refers to the integration of computer networks, telecommunications networks, and CATV networks, that is, traditional telecommunication networks, computer networks and cable television networks will tend to infiltrate and merge with each other, or the technology that covers three services, including video, voice and data, built on a network platform. It is an extension of the concept of ISDN, and is also a prerequisite for breaking the monopoly of the industry and unified planning and management of the three major network construction.
Characteristics of three networks in one
As an unified network system, three networks in one, built in full-digital network facilities, back up all the communication services, including data, voice and video. Therefore, such a network system should have the following essential characteristics :
1. "Transparency" between networks
The network is interoperable on the physical layer, that is, when the signals of one network can be transmitted directly or through organization, transformation, transmission to another network, and then transmitted to the terminals of other users through another network without alternation of the original information. That is, the network should be transparent to each other.
2. Sharing of network resources
Connecting to only one physical network, users can use the resources of other networks or exchange data with users on other networks to make voice.
3. Independence of the network
In the application layer, although the networks infiltrate and intersect with each other, they can be independent of each other, and they can develop their new business independently as before in their respective networks.
4. Compatibility of network
Protocol compatibility between networks means that because each network has its own protocol, information must be transferred from one network to another to meet the protocol requirements of the network.
In order to truly integrate the three networks, realize the one-network transmission of all kinds of information, such as voice, video, data, and provide better quality of service, we must have broadband for transmission, exchange, and access at the same time. Only when all kinds of information are processed uniformly in each link of the network, can the technical premise of the three networks exist in one.
This article comes from Jiangsu Hansheng Cable Technology Co., Ltd., http://www.jshansheng.com. Please reprint with the source indicated!