1, communication optical fiber cable development brief history
In 1966, the ethnic Chinese scientist Dr Charles kao, published a landmark paper surface with Yu Guangpin optical fiber waveguide, theoretically predict fiber will become the communication transmission medium; In 1970, corning, produced the first optical fiber attenuation is less than 20 db/km; In 1976, the United States launched the world's first practical optical fiber communication system, marks the beginning of the development of optical communication.
For more than thirty years, optical communication and optical fiber cable technology has experienced four stages of development, now entering the fifth phase. The first stage is from 1976 to the early 1976 s, the system work in 0.8 mu m wavelength, the multimode optical fiber, restricted by mode between dispersion, transmission rate under 100 MB/s, about 10 km relay distance; The second stage is the 1980 s, the system work in 1.3 mu m wavelength, single-mode fiber began to appear, transmission rate, extended to Gb/s level, relay distance expanded to about 50 km, 1984, ITU - T made the g. 652 standard single-mode optical fiber (SSMF); The third stage from 1980 s to the mid - 1990 - s, the system work in 1.5 mu m wavelength, relay distance expanded to 100 km, with the rate to the 10 gb/s ascension, in order to overcome the influence of dispersion, ITU - T made the g. 653 dispersion-shifted fiber (DSF) standards; Fourth stage from the mid - 1990 - s to mid - 2000 - s, logo is wavelength division multiplexing (WDM) system and the application of erbium-doped fiber amplifier (EDFA), greatly expanded the regeneration distance and system capacity, the DSF fiber cannot support WDM system, ITU - T in 1996 formulated the g. 655 a non-zero dispersion-shifted fiber (NZDSF) standard, then to g. 652 and g. 655 standard repeated modifications.
The current development of optical communication and optical fiber cable in the fifth stage, characterized by optical communication technology penetrated into all aspects of telecom network, the demand for fiber optic cable tend to diversification. ITU - T in 2004 formulated the g. 656 standard, satisfy the backbone network and metropolitan area network available to extend the WDM transmission wavelength range of requirements; In 2006 formulated the g. 657 standard, satisfy the requirement of the cloth of FTTx fiber to bring reduce bending loss. This article will be discussed in more detail in chapter 3 telecom network construction in the new period requirement for optical fiber cable.
§ 2, fiber optic cable application status in our country
The development of optical fiber cable industry in China is synchronous with the world, from 1978 to 1978, just after thirty years. Beginning in the 1980 s in China communication optical fiber cable laying, large-scale construction is after 1990, after 20 years of construction, has completed a some of the best in the world of large-scale optical fiber cable network, covering the national urban and rural areas. According to the ministry of information industry issued the 2006 statistics bulletin of the telecommunication industry, 2006 to 4.259 million kilometers, the total length of the fiber optic cable line the country to the total length of 88.934 million kilometers of fiber optical fiber core.
Now in our country network optical fiber type to g. 652 and g. 655 is given priority to, including g. 652 majority. The vast majority of local networks optical fiber are g. 652 optical fiber, the backbone of g. 655 optical fiber has certain proportion, provincial trunk line of China telecom, for example, g. 652 and g. 655 ratio is about 2:1, the total length of the fiber core of g. 655 optical fiber laying s are mainly in the late 1990 s to the early 2000 s, with large effective area fiber (LEAF) class. Trunk cable have loose tube gysts and center pipe type two kinds of structure, give priority to with the former. Main cable is given priority to with directly buried installation way, the individual area using aerial or pipe.
S relatively late due to construction, the fiber optic cable performance condition overall is good, but some early cable ageing phenomenon began to appear. Unlike other communication system, in the construction of backbone fiber optic cable, for the high cost of construction project, fiber optic cable with low proportion of purchase cost, but also in the shrinking, so operators most concern is the quality and long-term stability, once laying, requires that its normal running long enough.
§ 3, telecom network construction in the new period requirement for optical fiber cable
The changes in the business environment and the development of optical communication technology puts forward new requirements for fiber optic cable, this chapter will according to the backbone network, metropolitan area and access to different levels of business, and the characteristics of the communication technology, optical fiber cable is analyzed through the telecom network construction in the new period of requirements.
§ 3.1, backbone requirements for fiber optic cable
The current IP business remain high speed growth, such as China telecom ChinaNet, in the predictable future will be more than 30% of the annual growth rate. And rate of router interface is from 10 gb/s to 40 gb/s development, 100 gb/s interface also has emerged. In order to adapt to the changes in the business environment, the development trend of backbone network is less higher channel rate, channel spacing, greater system capacity, flexible light domain networking, etc., specific include the following several aspects to the requirement of optical fiber cable.
First, the smaller the PMD (polarization mode dispersion) parameters. High-speed WDM systems require lower coefficient of optical fiber PMD, such as 40 gb/s WDM systems have been unable to the PMD coefficient over 0.5 ps/SQRT (km) on the optical fiber carrying, only less than 0.1 ps/SQRT (km) is a new optical fiber can ensure its performance. G. 652 b/D, g. 655 c/D/E, g. has 656 standard cabling PMDQ parameters must be better than 0.1 ps/SQRT (km), mainstream manufacturers products parameters can be less than 0.05 ps/SQRT (km).
Second, the proper dispersion coefficient and the effective area. With the improvement of transmission rate, the decrease of the channel spacing, the extension of distance relay, various nonlinear effect is more serious, high speed (40 gb/s and above) within the channel WDM system also exists serious nonlinear. Studies have shown that appropriate increased fiber dispersion coefficient, effective area, is helpful to suppress nonlinear effect. Therefore, reasonable dispersion coefficient and the effective area is an important characteristic of future backbone fiber.
Third, loss coefficient and available wavelength range is also need to consider factors. The optical attenuation coefficient is close to theoretical limits. Extension available wavelength range from growing bandwidth pressure, our backbone WDM system, the work is currently in the C band, the future is likely to expand to the l-band even s-band, require backbone fiber such as C + S + L band has a reasonable dispersion coefficient and attenuation coefficient, can support the WDM transmission.
Above all, the future backbone of the requirements of fiber optic cable is reasonable and lower coefficient of PMD dispersion coefficient and the effective area and expand the available band more stable, lower transmission loss, etc. G. 652 d optical fiber is the best choice of the backbone, the future should focus on g. 656, etc. The development of new type of optical fiber.
§ 3.2, metropolitan area network requirements for fiber optic cable
Is different from the backbone network, metropolitan area network is characterized by short transmission distance, low transmission capacity, business type and rate of diversification, metropolitan area network cable also presents the overall amount of large, high cost sensitivity, etc. Metropolitan area transport technology diversification, existing work in 1310 nm band of PDH and SDH system at low speed, there is also a work in the 1550 nm band high-speed SDH system and DWDM systems, there are CWDM system, difficult to use a kind of optical fiber to achieve to meet all requirements. In addition, the man also has a hierarchical structure, different levels have different requirements on the performance of fiber optic cable, this section is the core of the metropolitan area network and convergence layer and access layer will be discussed in the next section.
Aiming at 1310 nm band application, g. 652 optical fiber natural is preferred, but with the progress of technology, g. 655 e and g. 656 optical fiber can also work in the 1310 nm band; In DWDM applications, the performance requirements for fiber optic cable is in line with the backbone, g. 652 d optical fiber is the best choice; Based on CWDM, g. 652 c/D and g. 656 optical fiber can support the whole band of CWDM transmission, especially g. 656 optical fiber, not only can be used wide wavelength range, and the parameters such as dispersion, loss is moderate, is the best choice to support CWDM system.
Above all, comprehensive consider price factors, the g. 652 d optical fiber is the best choice for metropolitan area network, the future should focus on g. 655 e, g. 656 new type of optical fiber, etc.
§ 3.3, access to the requirements of fiber optic cable
Optical fiber access network equipment connected directly to the customer, there is no guarantee that good/cloth fiber laying conditions. And the principle of optical fiber transmission determines not arbitrary curved like wire, must ensure that the bending radius can be big enough to ensure that the appropriate signal loss (traditional g. 652 optical fiber smallest bending radius is generally greater than 25 mm), this feature increases the difficulty of construction, raise the cost of the fabric fibers.
In line with the business promotion, FTTx fiber access network is proposed to reduce Macro bending Loss (Macro - bending Loss), optical fiber manufacturers launched some products, in the g. 652 standard at the same time, Macro bending Loss is orders of magnitude range reduced. A new type of any individual product, such as NTT bend light jump line (Free Bending Optical Fiber Cord), not only can achieve 90 - degree bend, can bind, knot, cloth Fiber convenience close to power lines. ITU - T released at the end of 2006 g. 657 standard, defines the characteristic parameters of this kind of fiber optic cable.
Longitudinal, determine the costs of access network is the most important factors on the selection of optical fiber bend loss and macro, currently from g. 652 optical fiber bending performance more excellent product selection, at the same time actively tracking the new g. 657 optical fiber development, when conditions are ripe to introduce web application now.
§ 4, optical fiber cable industry outlook
First, with the steady growth of broadband, "light into the copper retreat" is the consensus of operators, including China telecom, FTTx over the next few years will inevitably become the focus of network construction. The extension of local networks optical fiber to the last mile will be in the next few years to promote the development of optical fiber cable demand.
Second, as the backbone of DWDM transmission system at high speed, large capacity and the optical domain network evolution, and performance of optical cable network topology, optical fiber cable are put forward new requirements, operators such as mending their nets fiber optic cable, fiber core optimization construction requirements. Not only bring certain demand of fiber optic cable, but also will promote the further development of the optical fiber cable technology.
In conclusion, analysis of business developing trend and network construction in the new period needs, the status of optical communication in the network will continue to strengthen, the prospects of optical fiber cable industry is a good thing. Each manufacturer shall conform to the needs of the development of the business and technical research and development and production meet the demand of network construction, cost-effective advantage of optical fiber cable products at the same time, actively promote industry into the benign development track.
In 1966, the ethnic Chinese scientist Dr Charles kao, published a landmark paper surface with Yu Guangpin optical fiber waveguide, theoretically predict fiber will become the communication transmission medium; In 1970, corning, produced the first optical fiber attenuation is less than 20 db/km; In 1976, the United States launched the world's first practical optical fiber communication system, marks the beginning of the development of optical communication.
For more than thirty years, optical communication and optical fiber cable technology has experienced four stages of development, now entering the fifth phase. The first stage is from 1976 to the early 1976 s, the system work in 0.8 mu m wavelength, the multimode optical fiber, restricted by mode between dispersion, transmission rate under 100 MB/s, about 10 km relay distance; The second stage is the 1980 s, the system work in 1.3 mu m wavelength, single-mode fiber began to appear, transmission rate, extended to Gb/s level, relay distance expanded to about 50 km, 1984, ITU - T made the g. 652 standard single-mode optical fiber (SSMF); The third stage from 1980 s to the mid - 1990 - s, the system work in 1.5 mu m wavelength, relay distance expanded to 100 km, with the rate to the 10 gb/s ascension, in order to overcome the influence of dispersion, ITU - T made the g. 653 dispersion-shifted fiber (DSF) standards; Fourth stage from the mid - 1990 - s to mid - 2000 - s, logo is wavelength division multiplexing (WDM) system and the application of erbium-doped fiber amplifier (EDFA), greatly expanded the regeneration distance and system capacity, the DSF fiber cannot support WDM system, ITU - T in 1996 formulated the g. 655 a non-zero dispersion-shifted fiber (NZDSF) standard, then to g. 652 and g. 655 standard repeated modifications.
The current development of optical communication and optical fiber cable in the fifth stage, characterized by optical communication technology penetrated into all aspects of telecom network, the demand for fiber optic cable tend to diversification. ITU - T in 2004 formulated the g. 656 standard, satisfy the backbone network and metropolitan area network available to extend the WDM transmission wavelength range of requirements; In 2006 formulated the g. 657 standard, satisfy the requirement of the cloth of FTTx fiber to bring reduce bending loss. This article will be discussed in more detail in chapter 3 telecom network construction in the new period requirement for optical fiber cable.
§ 2, fiber optic cable application status in our country
The development of optical fiber cable industry in China is synchronous with the world, from 1978 to 1978, just after thirty years. Beginning in the 1980 s in China communication optical fiber cable laying, large-scale construction is after 1990, after 20 years of construction, has completed a some of the best in the world of large-scale optical fiber cable network, covering the national urban and rural areas. According to the ministry of information industry issued the 2006 statistics bulletin of the telecommunication industry, 2006 to 4.259 million kilometers, the total length of the fiber optic cable line the country to the total length of 88.934 million kilometers of fiber optical fiber core.
Now in our country network optical fiber type to g. 652 and g. 655 is given priority to, including g. 652 majority. The vast majority of local networks optical fiber are g. 652 optical fiber, the backbone of g. 655 optical fiber has certain proportion, provincial trunk line of China telecom, for example, g. 652 and g. 655 ratio is about 2:1, the total length of the fiber core of g. 655 optical fiber laying s are mainly in the late 1990 s to the early 2000 s, with large effective area fiber (LEAF) class. Trunk cable have loose tube gysts and center pipe type two kinds of structure, give priority to with the former. Main cable is given priority to with directly buried installation way, the individual area using aerial or pipe.
S relatively late due to construction, the fiber optic cable performance condition overall is good, but some early cable ageing phenomenon began to appear. Unlike other communication system, in the construction of backbone fiber optic cable, for the high cost of construction project, fiber optic cable with low proportion of purchase cost, but also in the shrinking, so operators most concern is the quality and long-term stability, once laying, requires that its normal running long enough.
§ 3, telecom network construction in the new period requirement for optical fiber cable
The changes in the business environment and the development of optical communication technology puts forward new requirements for fiber optic cable, this chapter will according to the backbone network, metropolitan area and access to different levels of business, and the characteristics of the communication technology, optical fiber cable is analyzed through the telecom network construction in the new period of requirements.
§ 3.1, backbone requirements for fiber optic cable
The current IP business remain high speed growth, such as China telecom ChinaNet, in the predictable future will be more than 30% of the annual growth rate. And rate of router interface is from 10 gb/s to 40 gb/s development, 100 gb/s interface also has emerged. In order to adapt to the changes in the business environment, the development trend of backbone network is less higher channel rate, channel spacing, greater system capacity, flexible light domain networking, etc., specific include the following several aspects to the requirement of optical fiber cable.
First, the smaller the PMD (polarization mode dispersion) parameters. High-speed WDM systems require lower coefficient of optical fiber PMD, such as 40 gb/s WDM systems have been unable to the PMD coefficient over 0.5 ps/SQRT (km) on the optical fiber carrying, only less than 0.1 ps/SQRT (km) is a new optical fiber can ensure its performance. G. 652 b/D, g. 655 c/D/E, g. has 656 standard cabling PMDQ parameters must be better than 0.1 ps/SQRT (km), mainstream manufacturers products parameters can be less than 0.05 ps/SQRT (km).
Second, the proper dispersion coefficient and the effective area. With the improvement of transmission rate, the decrease of the channel spacing, the extension of distance relay, various nonlinear effect is more serious, high speed (40 gb/s and above) within the channel WDM system also exists serious nonlinear. Studies have shown that appropriate increased fiber dispersion coefficient, effective area, is helpful to suppress nonlinear effect. Therefore, reasonable dispersion coefficient and the effective area is an important characteristic of future backbone fiber.
Third, loss coefficient and available wavelength range is also need to consider factors. The optical attenuation coefficient is close to theoretical limits. Extension available wavelength range from growing bandwidth pressure, our backbone WDM system, the work is currently in the C band, the future is likely to expand to the l-band even s-band, require backbone fiber such as C + S + L band has a reasonable dispersion coefficient and attenuation coefficient, can support the WDM transmission.
Above all, the future backbone of the requirements of fiber optic cable is reasonable and lower coefficient of PMD dispersion coefficient and the effective area and expand the available band more stable, lower transmission loss, etc. G. 652 d optical fiber is the best choice of the backbone, the future should focus on g. 656, etc. The development of new type of optical fiber.
§ 3.2, metropolitan area network requirements for fiber optic cable
Is different from the backbone network, metropolitan area network is characterized by short transmission distance, low transmission capacity, business type and rate of diversification, metropolitan area network cable also presents the overall amount of large, high cost sensitivity, etc. Metropolitan area transport technology diversification, existing work in 1310 nm band of PDH and SDH system at low speed, there is also a work in the 1550 nm band high-speed SDH system and DWDM systems, there are CWDM system, difficult to use a kind of optical fiber to achieve to meet all requirements. In addition, the man also has a hierarchical structure, different levels have different requirements on the performance of fiber optic cable, this section is the core of the metropolitan area network and convergence layer and access layer will be discussed in the next section.
Aiming at 1310 nm band application, g. 652 optical fiber natural is preferred, but with the progress of technology, g. 655 e and g. 656 optical fiber can also work in the 1310 nm band; In DWDM applications, the performance requirements for fiber optic cable is in line with the backbone, g. 652 d optical fiber is the best choice; Based on CWDM, g. 652 c/D and g. 656 optical fiber can support the whole band of CWDM transmission, especially g. 656 optical fiber, not only can be used wide wavelength range, and the parameters such as dispersion, loss is moderate, is the best choice to support CWDM system.
Above all, comprehensive consider price factors, the g. 652 d optical fiber is the best choice for metropolitan area network, the future should focus on g. 655 e, g. 656 new type of optical fiber, etc.
§ 3.3, access to the requirements of fiber optic cable
Optical fiber access network equipment connected directly to the customer, there is no guarantee that good/cloth fiber laying conditions. And the principle of optical fiber transmission determines not arbitrary curved like wire, must ensure that the bending radius can be big enough to ensure that the appropriate signal loss (traditional g. 652 optical fiber smallest bending radius is generally greater than 25 mm), this feature increases the difficulty of construction, raise the cost of the fabric fibers.
In line with the business promotion, FTTx fiber access network is proposed to reduce Macro bending Loss (Macro - bending Loss), optical fiber manufacturers launched some products, in the g. 652 standard at the same time, Macro bending Loss is orders of magnitude range reduced. A new type of any individual product, such as NTT bend light jump line (Free Bending Optical Fiber Cord), not only can achieve 90 - degree bend, can bind, knot, cloth Fiber convenience close to power lines. ITU - T released at the end of 2006 g. 657 standard, defines the characteristic parameters of this kind of fiber optic cable.
Longitudinal, determine the costs of access network is the most important factors on the selection of optical fiber bend loss and macro, currently from g. 652 optical fiber bending performance more excellent product selection, at the same time actively tracking the new g. 657 optical fiber development, when conditions are ripe to introduce web application now.
§ 4, optical fiber cable industry outlook
First, with the steady growth of broadband, "light into the copper retreat" is the consensus of operators, including China telecom, FTTx over the next few years will inevitably become the focus of network construction. The extension of local networks optical fiber to the last mile will be in the next few years to promote the development of optical fiber cable demand.
Second, as the backbone of DWDM transmission system at high speed, large capacity and the optical domain network evolution, and performance of optical cable network topology, optical fiber cable are put forward new requirements, operators such as mending their nets fiber optic cable, fiber core optimization construction requirements. Not only bring certain demand of fiber optic cable, but also will promote the further development of the optical fiber cable technology.
In conclusion, analysis of business developing trend and network construction in the new period needs, the status of optical communication in the network will continue to strengthen, the prospects of optical fiber cable industry is a good thing. Each manufacturer shall conform to the needs of the development of the business and technical research and development and production meet the demand of network construction, cost-effective advantage of optical fiber cable products at the same time, actively promote industry into the benign development track.
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