Optical Communication

1. Engr. Abbas Abbasi
Fiber Optic Communications
An Introduction

2. Multiplexing
 To utilize the system capacity fully, it is necessary to transmit many channels
simultaneously through multiplexing
 There are two different types of multiplexing:
 Time Division Multiplexing (TDM)
 Frequency Division Multiplexing (FDM) or Wavelength Division Multiplexing (WDM)
 Code Division Multiplexing

3. Time Division Multiplexing (TDM)

4. Time Division Multiplexing (TDM)…
Bit slot divided into 5 minor bit slots
5 Channels multiplexed
Single channel bit rate – 64 Kb/s
5 channel composite bit rate – 320 Kb/s

5. Frequency Division Multiplexing (FDM)

6. Frequency Division Multiplexing (FDM)…
Broadcasting of radio
Television channels

7. Wavelength Division Multiplexing (WDM)

8. TDM Digital Hierarchies

9. TDM Digital Hierarchies…

10. TDM Digital Hierarchies…
64 kbps
2.048 Mbps 1.544 Mbps 1.544 Mbps
6.312 Mbps 6.312 Mbps
8.448 Mbps
34.368 Mbps
139.264
Mbps
44.736 Mbps 32.064 Mbps
97.728 Mbps
274.176 Mbps
CEPT N.A. Japan
4
3
2
1
0
level
* 30
* 24
* 24
* 4
* 4
* 4
* 4
* 7
* 6
* 4
* 5
* 3
E1
E2
E3
E4
T1
T2
T3
T4
J1
J2
J3
J4

11. SONET/SDH
 Synchronous Optical Network (SONET)
 Synchronous Digital Hierarchy (SDH)
Optical Carrier
Synchronous Transport Module Bit rate for STM-7 ?
Bit Rate for OC-180 ?

12. Modulation Formats
 Return to Zero (RZ)
 Nonreturn to Zero (NRZ)

13. Modulation Techniques
 Amplitude Shift Keying (ASK)
 Frequency Shift Keying (FSK)
 Phase Shift Keying (PSK)

14. Amplitude Shift Keying (ASK)

15. Frequency Shift Keying (FSK)

16. Phase Shift Keying (PSK)

17. Optical communication systems

18. Lightwave system components

19. Fiber Toolkits

20. End of second module
 Thank you