FTTD access technology is an emerging network technology, which has been applied to a certain extent in foreign countries. But because of the cost of optical fiber and optical fiber in technology, construction, environmental protection, security and other factors, FTTD in the country only in some government and security sector applications, a new transmission medium - "plastic optical fiber," the emergence of FTTD applications will be A new transmission medium - "plastic optical fiber", the application of FTTD will be more and more extensive.
The advantages of FTTD fiber
Fiber To The Desktop (Fiber To The Desktop) refers to the optical fiber instead of the traditional copper transmission medium directly to the user terminal computer, so that the user terminal throughout the optical fiber to achieve network access. Copper cable system is still dominant in the workspace subsystem due to low price and cost, simple installation and construction, easy maintenance and support for PoE Ethernet technology. However, with the development of optical communication technology, the bottleneck of copper cable system upgrade and the complexity of the application environment, etc., the advantages of optical fiber are becoming more and more obvious:
(1) Optical fiber can support longer distance and higher bandwidth transmission. A new generation of OM4 multimode fiber optic cables in the 850nm wavelength to provide at least 4700MHz-km effective mode bandwidth, 3500MHz-km injected mode bandwidth, in the 1300nm wavelength to provide at least 500MHz-km injected mode bandwidth, are to support a maximum of 550m of 10Gbps serial transmission, as well as more than 150m of 40/100Gbps transmission. Zero Water Peak OS2 single-mode fiber optic cables can even reach up to 40 kilometers in 10 Gigabit Ethernet. This is simply not possible with copper systems. When the transmission distance of the information point exceeds 100 meters, the choice of copper cable system cabling, you must increase the area management room, additional network equipment and cabling materials, which will lead to an increase in the project engineering costs, and, there may be an increase in the link failure points. However, fiber optic systems can easily solve this problem.
(2) optical fiber is a non-metallic material, data transmission on light waves, can avoid external electromagnetic interference EMI and radio frequency interference RFI, for example, in some special wiring environment: air-conditioning rooms, hospitals, medical equipment rooms, machinery manufacturing plants, etc.; and, no crosstalk between the core, the signal will not be leaked to the outside world, play a very good role in the confidentiality of the role of, for example, in some information requirements The confidentiality of the place: public prosecutors and law enforcement agencies, the military industry, high-tech R & D units, and so on.
(3) Wide range of ambient temperature; communication without electricity, can be used in flammable, explosive places, the use of safe.
(4) Chemical corrosion resistance, long service life.
(5) Different sheath materials and internal structure can cope with the harsh office environment.
(6) The development of copper cable system from Cat5 to Cat6A, in the structure of the increased cross-bone, shielding (or even double shielding), the wire diameter has become larger and larger, which invariably increase the cost of raw materials, transportation costs, installation of auxiliary materials, installation and construction costs and testing costs, etc. of copper cables. Copper cable system from Cat5 four test parameters, the development of a dozen, but also more than one external crosstalk test parameters, making the Cat6A cabling system acceptance test more cumbersome and time-consuming. However, the development of optical fiber to today, the volume and weight has not changed, the test parameters are generally only two: "attenuation" and "length". And, with the development of optical communication technology, the cost of raw materials has a tendency to decline, installation and construction also become more and more simple.
(7) The application of 10GBASE-LRM enables OM1 and OM2 fiber optic cables to reach a transmission distance of 300 meters in 10Gb Ethernet, which greatly reduces cabling costs.
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It is for these reasons that the application of fiber-to-the-desktop FTTD has turned into a future development trend, and some people even take the Cat6A system as the end of the copper era, and optical fiber will be the ultimate choice for the network.