- •For course design
- •3 Selection of route, type of cable and transmission systems
- •3.1 Short characteristic of terminal points
- •3.2 The choice of fiber optic transmission lines route
- •3.3 Selection and justification of optic fiber type
- •3.4 Selection and justification the construction and type of optical cable
- •3.5 Selection and justification of fiber optic transmission system
- •3.6 Control questions
- •4.3 Choice and substantiation of the optical cable
- •4.2 Choice and substantiation of the type of optical fibers
- •4.2 Choice and substantiation of the Fiber optic transmission system (fots)
- •5 Calculation of optical properties of fibers and parameters of cable transfer
- •5.1 Determination of optical fiber parameters
- •5.2 Determination of losses in optical fiber
- •5.3 Calculation of running dispersion of the signal in single mode optical fiber
- •6 Calculation of regeneration length of optical fiber transmission lines, chart of energy levels
- •6.1 Calculation of the length of the regeneration section by attenuation
- •6.2 Calculate the length of the regeneration section by dispersion
- •6.3 Placement regeneration points along the route of focl
- •6.4 Constructing a chart levels of energy potential fots at the length of one area of regeneration
- •7 Protection of optical cable from the influence of external electromagnetic fields
- •Protection of optical cables from lightning strikes
- •Calculation of the dangerous effects of magnetic influences
- •Calculation of reliability of linear structures fots
- •9 Organization of works on construction and installation project lines. Budget and financial calculation of linear structures of focl
- •9.1 Organization of construction works
- •9.2 Budget and financial calculations
4.2 Choice and substantiation of the Fiber optic transmission system (fots)
The type and characteristics of FOTS are selected according to Table. 4.5, depending on the required amount of information transfer, which is given by the number of basic (primary) digital streams (BDS), operating wavelength of the equipment, the distance between the end points and towns along the route FOTL and the principles of construction of communication networks, which solves the problem of a given line transmission.
Specifications of FOTS synchronous digital hierarchy, according to [8] are presented in Table. 4.5.
Table 4.5 - Specifications of synchronous FOTS
ЕКД |
Shortened |
Standard |
||||||
Wavelength, mkm |
1,31 |
1,55 |
1,31 |
1,55 |
||||
STM-1 |
||||||||
Number of digital streams E1 |
63 |
|||||||
Speed of optical compression, Mbit / s |
155 |
|||||||
Average output power, dBm |
-8 |
2 |
2 |
2 |
||||
Minimum receiver sensitivity, dBm |
-34 |
|||||||
The width of the spectral line radiation , nm |
<0,4 |
<0,4 |
<0,25 |
<0,25 |
||||
Maximum chromatic dispersion , ps/nm, на ЕКД |
55000 |
|||||||
STM-4 |
||||||||
Number of digital streams E1 |
252 |
|||||||
Speed of optical compression, Mbit / s |
622 |
|||||||
Average output power, dBm |
-11 |
-0,5 |
-0,5 |
4,5 |
||||
Minimum receiver sensitivity, dBm |
-34 |
-36 |
-39 |
-45 |
||||
The width of the spectral line radiation , nm |
<2,5 |
<1,7 |
<0,5 |
<0,5 |
||||
Maximum chromatic dispersion , ps/nm, на ЕКД |
15000 |
|||||||
STM-16 |
||||||||
Number of digital streams E1 |
1008 |
|||||||
Speed of optical compression, Mbit / s |
2500 |
|||||||
Average output power, dBm |
-3 |
0 |
2 |
2 |
||||
Minimum receiver sensitivity, dBm |
-27 |
-28 |
-27 |
-29.5 |
||||
The width of the spectral line radiation , nm |
<1 |
<0,6 |
<1 |
<0,6 |
||||
Maximum chromatic dispersion , ps/nm, на ЕКД |
10500 |
|||||||
STM-64 |
||||||||
Number of digital streams E1 |
4032 |
|||||||
Speed of optical compression, Mbit / s |
10000 |
|||||||
Average output power, dBm |
2 |
2 |
10 |
13 |
||||
Minimum receiver sensitivity, dBm |
-18 |
-18,5 |
-14 |
-21 |
||||
The width of the spectral line radiation , nm |
<0,1 |
|||||||
Maximum chromatic dispersion , ps/nm, на ЕКД |
10500 |
|||||||
Note. When you need to work on extended EKD on the transmitter output multiplexer optical amplifier (buster) is installed, thus increasing the energy potential of 7 - 15 dBm.