This presentation describes the losses in the optical fiber and how these losses are measured.

1. A New Approach for Identifying
Fiber Fault and Detecting
Failure Location
Presented by
SANKET S YAVALKAR
ME (E&TC)
Authors
M.S.AbRahman [1], Ng Boon Chuan[2],
Aswir Premadi[3],Kasmiran Jumari[4].
[1][2][3][4] University Kebangsaan, Malasysia

2. Flow of Paper :
 Abstract
 Aim
 Fault finding methods
 OTDR
 Experimental Setup
 Experimental Results
 Discussion on Results
 Conclusion

3. Abstract :
 This paper proposed and demostrate
the need of centralized failure
detection system (CFDS) with OTDR
.

4. Aim:
 Create a matlab based graphical user
interface (GUI) named as Centralized
Failure Detection System(CFDS).

5. Fiber Optic Testing
 After the cables are installed and terminated, it's time for
testing…..
 For every fiber optic cable plant, you will need to test for :
continuity
end-to-end loss
troubleshoot the problems

6. Getting Started …..
1. Have the right tools and test equipment for the
job. You will need:
 Source and power meter
 Reference test cables
 Fiber Tracer
 Cleaning materials
 OTDR and launch cable
2. Know how to use your test equipment
3. Know the network you're testing...
4. Safety first….

7.  Fiber optic testing includes three basic tests
that we will cover separately :
Optical Fiber Testing
Visual Inspection Loss testing Network Testing

8. 1.Visual Inspection [1]
1. Visual Tracing
2. Visual Fault Location
3. Visual Connector Inspection

9. 2. Loss Testing [1]
1. Power Testing

10. 2. Testing Loss
 Loss = Transmitted – Received
 Loss =>noise
Noise due to:
 Source
 Cable

11. Loss testing [1]
Loss in
Cable
single- double-
ended loss ended loss

12. 1.Single-ended loss [1]
Measures :
 the loss of the connector
mated to the launch cable
 the loss of any fiber

13. 2.Double-ended loss[1]
Measures :
 Two connectors' loses ,
one on each end
Loss of all the cable or
cables in between

14. What Loss Should You Get
When Testing Cables? [1]
 Lets take an example,
I. For each connector, figure 0.5 dB loss (0.7 max)
II. For each splice, figure 0.2 dB
III. For multimode fiber, 0.1 dB per 100 feet for 850
nm
OR
For singlemode fiber, 0.5 dB per km for 1300 nm
So for the loss of a cable plant
= (0.5 dB X # connectors) + (0.2 dB x # splices) +
fiber loss on the total length of cable

15. 3. Network Testing [2]
 OTDR Testing
 Operational Time Domain Reflectometer(OTDR).[1]

16. PRINCIPLE OF WORKING :

17. Advantages of CFDS with
OTDR:
OTDR CFDS

18. EXPERIMENTAL SETUP[3] :
PC OTDR
ONU

19. Flow Chart of Mechanism of Failure Location[3]
Start
Fiber measurement
Save it in OTDR
Transfer results into
computer
Activate the CFDS and
Display Graphs showing
results
Check
fiber’s
Status
Show faulty fiber and failure
location
End

20. Results : [3]
 Transferring files from FTB-100B into
computer :

21. Results [3]
 Execution display for test 8 in working
condition :

22. Results [3]
 Execution display for test 8 in non-working
condition :

23. Results : [3]
 Every 8 graphs displayed in Line’s Status
window for centralized monitoring :

24. Results : [3]
 Line 8 is failure at distance 15.1867
km:

25. Results : [3]
 Optical power in line 1 decreasing 0.595dB
at 15.1969km (In Line detail window):

26. Discussion
• Here Centralized failure detection
system (CFDS) is developed for the users
who are inexperianced or non-specialized
in optical fiber testing process.
• Besides, it locates the fiber break
or failure, drastically redusing
troubleshooting and repair time.

27. Conclusion

28. References
[1] http://www.LANshake.com/ fiber-optic-tutorial-testing.aspx.html
[2] EXFO, FTB-150 Optical Time Domain Reflectometer Series Instruction
Manual.
[3] R AHMAN M.S.A., NG B.C., “MATLAB-based graphical user interface
development for centralized failure detection system (CFDS) in SCAN
network”, Journal of Optical Communications 29(3), 2008, pp. 152–156.