Copper and Fiber Optic Cables

Transcription

1 Copper and Fiber Optic Cables Pietro Nicoletti piero[at]studioreti.it Cables-Engl - 1 P. Nicoletti: see note pag. 2

2 Copyright note These slides are protected by copyright and international treaties. The title and the copyrights concerning the slides (inclusive, but non only, every image, photograph, animation, video, audio, music and text) are the author s (see Page 1) property. The slides can be copied and used by research institutes, schools and universities affiliated to the Ministry of Public Instruction and the Ministry of University and Si Scientific Research and Technology, for institutional purpose, not for profit. In this case there is not requested any authorization. Any other complete or partial use or reproduction (inclusive, but not only, reproduction on discs, networks and printers) is forbidden without written authorization of the author in advance. The information contained in these slides are believed correct at the moment of publication. They are supplied only for didactic purpose and not to be used for installation-projects, products, networks etc. However, there might be changes without notice. The authors are not responsible for the content of the slides. In any case there can not be declared conformity with the information contained in these slides. In anycasethis note of copyright may never be removed and must be written also in case of partial use. Cables-Engl - 2 P. Nicoletti: see note pag. 2

3 Copper cables main characteristics The main characteristics of a transmission media are: Vp: Velocity of propagation of the signal expressed as c fraction (speed of the light in the empty space): values included between 0.5 and 0.8 c Z = r+ji impedance of the line conductors' dimension american AWG unit of measurement Diameter, electrical resistance Cables-Engl - 3 P. Nicoletti: see note pag. 2

4 AWG: American Wire Gage Scale to measure the copper wire dimension It is a geometrical regression with 39 values in the interval 000 gage g (0.460 diameter inch) and 36 gage (0.005 diameter inch) Every increase of a gage corresponds to a diameter relationship of: /39 1/39 ( ) 1/39 = 92 = Cables-Engl - 4 P. Nicoletti: see note pag. 2

5 Copper cables AWG 24 or 22 AWG for structured cabling system 26 AWG for patch cord AWG mm (Ø) mm 2 Kg/Km /Km Cables-Engl - 5 P. Nicoletti: see note pag. 2

6 Copper cable attenuation The attenuation is the output signal reduction with respect to the entry signal in the cable: attenuation linearly grows in db with the length of the cable and the feq frequencyenc square root to reduce the cable attenuation expanded insulators are used because improve the capacity Cables-Engl - 6 P. Nicoletti: see note pag. 2

7 Attenuation V 1 V 2 db = 20 log 10 (V 1 / V 2 2) Cables-Engl - 7 P. Nicoletti: see note pag. 2

8 Copper pair Cross-Talk Signal energy part induction on the near conductors, where a disturb becomes The phenomenon increases with increasing it by frequency It can be measured in several manners Cables-Engl - 8 P. Nicoletti: see note pag. 2

9 NEXT: Near End Cross-Talk Cross-Talk measured at the transmitter side V 1 V 3 NEXT db = 20 log 10 (V 1 / V 3 ) Cables-Engl - 9 P. Nicoletti: see note pag. 2

10 NEXT: Near End Cross-Talk The attenuation only makes the NEXT measure significant by the first mt of cable The measurement is necessary to both ends: dual NEXT V 1 V 3 Cables-Engl - 10 P. Nicoletti: see note pag. 2

11 FEXT: Far End Cross-Talk Cross-Talk measured at the receiver side V 1 V 4 FEXT db = 20 log 10 (V 1 / V 4 ) Cables-Engl - 11 P. Nicoletti: see note pag. 2

12 ACR ACR (Attenuation to Cross-Talk Ratio) Combination of attenuation and NEXT signal to noise ratio noise caused by Cross-Talk Required only by ISO and EN normative Cables-Engl - 12 P. Nicoletti: see note pag. 2

13 ELFEXT: Equal Level FEXT ~ ~ Cables-Engl - 13 P. Nicoletti: see note pag. 2

14 PSELFEXT (Power Sum ELFEXT) ~ ~ ~ ~ ~ ~ Cables-Engl - 14 P. Nicoletti: see note pag. 2

15 Velocity of propagation (Vp) The propagation p velocity of the signals on the transmission means is high, but not infinite, so the propagation time is little but not null It is necessary to ensure thatt delays do not exceed certain maximum values to ensure the protocol working V P 2/3 c (c is speed of the light in the empty space m/s) Cables-Engl - 15 P. Nicoletti: see note pag. 2

16 Delay skew Cables-Engl - 16 P. Nicoletti: see note pag. 2

17 Return loss Il return loss = reflections measurements Impedance Z 1 Z 2 Z 3 variations Cables-Engl - 17 P. Nicoletti: see note pag. 2

18 Shielded cable The shield presence can involve: bigger immunity to the electromagnetic disturb disturb radio emission reduction bigger constancy of the impedance if applied to single pair reduces the crosstalk It is necessary to make a correct screen grounding: Cables-Engl - 18 P. Nicoletti: see note pag. 2

19 Twisted pair cable Constituted by one or more twisted pair of copper conductors Used for voice, local nets, structured cabling system the electrical characteristic required for LAN are definitely higher than those for voice Lower bandwith than the coaxial one Reduced costs and simple installation Cables-Engl - 19 P. Nicoletti: see note pag. 2

20 Twisted Pair cable types UTP (Unshielded Twisted Pair): (Z = 100 ) FTP (Foiled Twisted Pair): (Z = 100 ) S-UTP o S-FTP: (Z = 100 ) STP (Shielded Twisted Pair): (Z = 150 ) Cables-Engl - 20 P. Nicoletti: see note pag. 2

21 UTP 100 pair 1 pair 2 pair 3 pair 4 Cables-Engl - 21 P. Nicoletti: see note pag. 2

22 FTP 100 Drain wire for shield continuity Foil shield pair 1 pair 2 pair 3 pair 4 Cables-Engl - 22 P. Nicoletti: see note pag. 2

23 S-UTP or S-FTP 100 Single foil shielded pair Copper braid pair 1 pair 2 pair 3 pair 4 Cables-Engl - 23 P. Nicoletti: see note pag. 2

24 STP 150 Know as Type 1IBM 22 AWG Cables-Engl - 24 P. Nicoletti: see note pag. 2

25 GLASS FIBER OPTIC Cables-Engl - 25 P. Nicoletti: see note pag. 2

26 Glass Fiber Optic It is a tiny and flexible glass material thread: an internal part called core an outside part called cladding core and cladding have different refraction indexes to border the light inside core CLADDING SECONDARY COATING CORE PRIMARY COATING Cables-Engl - 26 P. Nicoletti: see note pag. 2

27 Glass Fiber Optic characteristics The optic fibers are just suitable for point point links Total immunity to the electromagnetic troubles Characterized by two numbers n/m where: diameter n of the leading internal light part diameter m of the outside part Typical values in micron multimode 50/125, 62.5/125, 100/140 singlemode 8-10/125 Cables-Engl - 27 P. Nicoletti: see note pag. 2

28 Step-index multimode fiber Characteristics High modal dispersion Low bandwith M3 M1 M2 M4 M1 M4 M3 M2 Input signal Output signal T1 T2 Cables-Engl - 28 P. Nicoletti: see note pag. 2

29 Graded-index multimode fiber Graded-index fiber have a bandwith higher than step- index work in 1 st and 2 nd window (850 and 1300 nm) Cables-Engl - 29 P. Nicoletti: see note pag. 2

30 Singlemode fiber The fiber behaves like awaveguide admitting a single propagation mode: does not have modal dispersion the bandwith is very high, of the order of hundreds of GHz*Km work in 2 nd and 3 th window (1300 and 1500 nm) Cables-Engl - 30 P. Nicoletti: see note pag. 2

31 Wavelenght and optical components 100 Km) Attenuatio on (db X 10 5 LED\VCSEL LASER DIODE VCSEL LASER DIODE Cables-Engl - 31 P. Nicoletti: see note pag. 2

32 Fiber optic cable types Tight Break-out dual fiber patch cord Light-duty Loose Cables-Engl - 32 P. Nicoletti: see note pag. 2

33 Break-Out tight fiber optic cable Indoor installation Secondary coating External diameter 0.9 mm External diameter 2 3 mm Central Dielectric element Kevlar Fiber optic External diameter 250 m 250 m = 125 m + primary coating Sheath Toxfree or Low-smoke-fume Cables-Engl - 33 P. Nicoletti: see note pag. 2

34 Dual fiber patch cord Secondary coating External diameter 0.9 mm External diameter 2 3 mm Fiber optic External diameter 250 m 250 m m = 125 m m + primary coating Kevlar Sheath Toxfree o Low-smoke-fume Cables-Engl - 34 P. Nicoletti: see note pag. 2

35 Light-duty tight fiber optic cable Indoor/Outdoor installation Secondary coating External diameter 0.9 mm Central Dielectric element Kevlar Roditor resistant protection Fiber optic External diameter 250 m 250 m = 125 m + primary coating Sheath Toxfree o Low-smoke-fume Cables-Engl - 35 P. Nicoletti: see note pag. 2

36 Loose fiber optic cable Outdoor installation Central Dielectric element Tube Jelly filled Kevlar Roditor resistant protection Fiber optic Sheath External diameter 250 m 250 m = 125 m + primary coating Sheath Cables-Engl - 36 P. Nicoletti: see note pag. 2