The development of fiber-optic network

Abstract: The optical fiber communication based on light as the carrier, the use of high purity made of very fine glass optical fiber drawing as a transmission medium through photoelectric conversion, use light to transmit Information communication system. From the national backbone communications network to the metro and access network to the user, are basically means used to achieve optical fiber communications.

Keywords:: ultra-high speed fiber optic network transmission capacity of ultra-long haul DWDM optical network Automatically Switched Optical Network

1 status and development needs of the development of optical fiber communication based on light
the carrier, the use of high purity made of very fine glass optical fiber drawing as a transmission medium through photoelectric conversion, use light to transmit Information communication system. From the national backbone communications network to the metro and access network to the user, are basically means used to achieve optical fiber communications. Optical fiber communication technology and computer technology are the two core pillars of Information, the computer is responsible for digital Information, the input to the network; fiber is responsible for the Information transmission task. At present, China's total fiber optic cable laying nearly 400 million km, the cumulative amount of nearly 80 million km fiber. With the contemporary social and economic development, increasing the information surge capacity, to improve the information transmission speed and capacity, optical fiber communication technology, a breakthrough development, microelectronics, after becoming the important field of information technology.

With the online office, 3G mobile communications, remote mobile storage and other new business applications, people are fiber-optic network transmission speed and capacity demand growth and even some areas of the single-user access speeds required to achieve 1Gb / s, Therefore we must build faster, larger capacity fiber-optic network to meet the growing communications needs. In order to meet the higher quality of service requirements of users, an update on the primary transport protocol is also very important. Another fast-growing fiber optic network applications are grid computing and cloud computing commercialization in the next few years, such calculations will no longer be limited to scientific computing, and will be further extended to the commercial sector and military applications. Such as the successful application of military sensor grid and a cost of billions of dollars the U.S. Defense Department's "Global Information Grid" program, is the application of grid computing.


2 fiber-optic network technology
2.1 high-speed optical fiber transmission technology
people need high-speed fiber-optic network, large capacity, but so far we can use the transmission medium is still the best light. Because only the use of spectrum can give us plenty of bandwidth. High-speed optical fiber transmission technology are expanding along the transmission capacity of a single wavelength, ultra-long haul transmission and Dense Wavelength Division Multiplexing (DWDM) system in the development of three directions. Single-fiber data transmission capacity improved in more than 20 years times; ultra-long haul to achieve a 1.28T (128x10G) without regeneration send 8000Km; WDM laboratory has achieved the highest level of 273 wavelengths, each wavelength 40Gb.

2.2
fiber broadband access network must have the support of a variety of broadband services and applications can be carried out together, the potential of network capacity can really play. Wide variety of broadband access technologies, mainly in the following four: one is based on high-speed digital subscriber line (VDSL); the second is based on Ethernet Passive Optical Network (EPON) of the fiber to the home (FTTH); third, free-space optical system ( FSO); Fourth, wireless local area network (WLAN).

2.3
passive optical network passive optical network (PON) concept of a long time, it has to save fiber resources and reduce lines and external equipment failure rate and improve system reliability, maintenance cost savings on network protocol transparency features in the optical access network, playing an increasingly important role. At the same time, Ethernet (Ethernet) technology for its simple and practical, low cost, easy maintenance, scalability, standardization and a wide range of commercial hardware and software support features, almost completely dominated the local area network, with the IP business in the metro and trunk transmission rising proportion, also through the transfer rate Ethernet, manageability, and other improvements, and gradually to the access, metro or backbone network penetration. The combination of Ethernet and PON, they have an Ethernet passive optical network (EPON). It also has the advantages of Ethernet and PON is considered the major next-generation broadband access network technology. It is through a single optical access systems, data, voice and video integrated service access, and has a good economy. Industry generally believe that, FTTH is the ultimate broadband access solutions, and EPON will become a mainstream broadband access technology. The characteristics of the EPON network structure, the special advantages of broadband households, making the world's experts agreed that the passive optical network is to achieve "triple play" and address information superhighway "last mile" of the optimal transmission medium.

2.4
ASON optical network based on next-generation softswitch technology as the core, the use of large high-capacity dense wavelength sub-systems, with automatic configuration of large-capacity optical switch, a new generation of optical router, the species suitable for different occasions using the low-end optical systems (such as MSTP and RPR), composed of intelligent optical network. As early as 2002, AT & T in the OFC on the "intelligent optical networking has now become a reality." Building efficient and flexible important ASON optical cross-connect device node device (OXC) and optical add-drop multiplexers (OADM), along with the development of these devices, intelligent optical network with new development, which is automatically switched optical Network (ASON), its most prominent feature is introduced in the optical transmission network of independent intelligent control plane, control plane used to complete the auto-discovery route, the call connection management, protection and restoration, etc., to implement dynamic call connection to the network management.

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