Three nets new trend of future network development

Three nets new developmental trend of future network with optical fiber door ( FTTH技术) Gradual popularization, the beginning of three nets technology is also widely used. Three nets is refers to the telecommunications network, cable television network and computer network of mutual penetration and mutual compatibility, and gradually integrated into the unity of the world's information and communications network, the Internet is its core part, it can provide users with a variety of services such as voice, data, and cable TV. Someone may ask: we can through the transmission medium for voice and other radio and television services, why three nets technology must be used? In fact main power to promote the development of three nets technology is that it can save resource and cost down. In simple terms, radio and television, telecommunications, the Internet each cloth mesh, each pull line will cause the infrastructure of repeated construction and resource waste, and after the three network integration, can greatly reduce the construction investment, simplify network is dealt with, lowering maintenance costs. In addition, three nets technology also benefit is currently very hot in the development of smart home network. Three nets technology can save resources, lowering costs, mainly thanks to its network infrastructure, it mainly depends on the fiber door ( FTTH技术) The passive optical network ( 彩球,无源光网络) , particularly Ethernet passive optical network ( 以太无源光网络EPON,) 。 Several common network infrastructure in addition to the three nets, there are two kinds of network also USES the Ethernet passive optical network ( EPON) , the EPON + LAN ( Ethernet passive optical network and local area network (LAN) linking) And EPON + EOC ( Ethernet passive optical network) that is associated with the copper Ethernet 。 Below is the basis of the three network architecture: figure 1 EPON + LAN EPON + EPON and local area network (LAN 局域网,局域网) Together, voice and data services by light node Ethernet passive optical network ( EPON) Optical network units ( ONU、光网络单元) To provide, and local area network ( LAN） Access is mainly used as interactive command and broadband access. In EPON + LAN, the transmission of voice and data services of the Ethernet cable must be access to the user in the home, and cable TV service requires the light receiver first and then by coaxial cable transmission to the user (in the home As shown in figure 1) 。 Obviously, EPON + LAN need to user access two different cables in the home, not enough cost savings. EPON + EOC EPON + EOC can make full use of the existing copper infrastructure, is to use fiber optic cable to send data to the optical network unit ( ONU） And then with the help of copper Ethernet ( EOC） Through the original cable TV coaxial cable and cable TV signal on the data sent to users in the home of a solution ( As shown in figure 1) 。 However, compared with three nets, EPON + EOC can service very wired, the number of end users and the installation cost is high. Three nets in the three nets network, cable television, data and voice services can be through the optical fiber cable transmission respectively to wavelength division multiplexing ( WDM) Network, and then transmitted on a single fiber, finally through the Ethernet passive optical network ( EPON) The optical network unit ( ONU） To different user home ( As shown in figure 1) 。 Three nets is the integration of business, it not only inherited the original voice, data and video service, and through the integration of network, spawned more rich value-added business types, such as the teletext, VOIP, video, E-mail and network game, etc. , greatly expand the scope of business.