1. Submarine Cable System - Focusing on the Link between China & Korea -
Lecture on
Submarine Cable System
- Focusing on the Link between China & Korea -

2. Submarine Cable Systems between Korea and China
Beijing
Seoul
CKC
Taean
0.56Gbit/s x 1WDM x 2FP
Qingdao
Pusan
APCN2
10Gbit/s x 64WDM x 4FP
Chongming
C2C
10Gbit/s x 96WDM x 8FP
As you may know, many submarine cable systems have already instolled all over the world, of course including the link between Korea and China.
These days, most submarine cable systems are used for data transmission than voice communication.
And some of you are interested in thesubmarine cable system itself.
So today, I would like to talk about key technologies to realize the cable system between K&C.
KJCN
10Gbit/s x 24WDM x 12FP

3. Outline 1. Introduction 2. Configuration of Submarine Cable System
3. Transmission Technologies
- Experimental Results
4. How to realize the cable system between Korea and China ?
- Network configuration
- Cost
5. Conclusion

4. Outline 1. Introduction 2. Configuration of Submarine Cable System
3. Transmission Technologies
- Experimental Results
4. How to realize the cable system between Korea and China ?
- Network configuration
- Cost
5. Conclusion

5. Repeaterless system and Repeater system
SLTE
SLTE
Cable MC MC
Repeaterless System
SLTE : Submarine Line Terminating Equipment
MC : Maintenance Controller
LME : Line Monitoring Equipment
PFE : Power Feeding Equipment
SLTE
SLTE
Repeater
There are two kinds of submarine cable system.
One is Repeaterless system, the other is Repeater system.
As you can see in this figure, the configuration of Repeaterless system is very simple.
Repeaterless system consists of SLTE and MC.
On the other hand
LME
PFE
Cable
PFE
LME MC MC
Repeater System

6. What is “WDM” ? Wavelength Division Multiplexing Total capacity
10Gbit/s
x n WDM
Wavelength
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Optical Fiber
Multiplexer
Demultiplexer

7. Advantage of WDM : Upgrade
- Small initial investment
- Increase the system capacity when you need
without changing the wet plant
- After upgrade
- Initial
Cable capacity : 10Gbit/s
x N
Trans-mitter
Recei-ver
Repeater
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver

8. What is Maximum Number of Wavelength?
10Gbit/s per wavelength
Maximum Number of Wavelength
Repeater System
KJCN
Repeaterless
System
System Length [km]

9. Why is the Number of l Limited in Repeaterless System?
Trans-mitter
Recei-ver
Optical Fiber
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Loss (0.2dB/km)
Power
Transmitter
Receiver
Threshold of receiver
distance

10. > 3T bit/s / cable Upgrade Strategy - Repeater system
- Repeaterless system
Cable l
Increasing the # FP
(Use the dark fibers)
Increasing the # wavelength
> 3T bit/s / cable

11. Outline 1. Introduction 2. Configuration of Submarine Cable System
3. Transmission Technologies
- Experimental Results
4. How to realize the cable system between Korea and China ?
- Network configuration
- Cost
5. Conclusion

12. Key Technologies for Repeaterless System
Number of wavelengths :
~16 (Capacity : ~160Gbit/s /fiber)
1~2 (Capacity : 10~20Gbit/s /fiber)
- Optical Booster and Preamplifier
Optical Booster
Optical Pre-amplifier
- Raman Amplifier
- Remote EDFA Amplifier
Remote Pump Source
FEC
- FEC (Forward Error Correction)
Trans-mitter
Recei-ver

13. Repeaterless System - 10Gbit/s x 100WDM, 200km -
Trans-mitter
Recei-ver
Optical Fiber
Multiplexer
Demultiplexer
100WDM
200km
BER : 10-9
Spectrum after 200km transmission
Transmission characteristics

14. Key Technologies for Repeater System
Fiber (~100km)
FEC
Recei-ver
Trans-mitter
How to transmit a large number of wavelength……..
1. By making the signal bandwidth wider
2. By making the wavelength spacing narrower

15. Repeater System - 10Gbit/s x 200WDM, 9200km -
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Trans-mitter
Recei-ver
Repeater
Fiber (~45km)
BER
BER : with super FEC
Output of Transmitter
After 9,200km Transmission

16. Outline 1. Introduction 2. Configuration of Submarine Cable System
3. Transmission Technologies
- Experimental Results
4. How to realize the cable system between Korea and China ?
- Network configuration
- Cost
5. Conclusion

17. Key Factors to Realize the System
- Demand
- Feasibility of transmission technologies
- Location of cable landing station
- Network configuration
- Cost

18. Comparison of New and Existing Cable Landing Station
Using the Existing Stations is preferable !

19. Network Configuration
Plan the optical cable system between Korea and China
using the Existing cable landing stations.
Taean (泰安) - Qingdao (青島)
Distance : ~ 560km
Taean : Exist.
Qingdao : Exist.
560km
3 options of Network configuration

20. Network Configuration
Repeater System
Option 1
Repeaterless System
Option 2
New Station
Taean : Exist.
Repeaterless System +
Backhaul System
Option 3
Qingdao : Exist.

21. Conditions for Cost Estimation
Initial
After Upgrade
Note: 5 Repeaters are assumed in Repeater system (Option 1).

22. Cost for Initial Investment
Price(M$)
Initial

23. Cost for Upgrade After Upgrade (Ultimate)
Price(M$)
After Upgrade
(Ultimate)
Initial

24. Terminal Equipment Bay
Repeaterless System
EDF for remote amplification
LTU with FEC
for undersea
cable system
WTU
Up-stream
Remote EDF Pump Source
Down-stream
1FP
LTU : Line Terminating Unit
WTU : Wavelength Terminating Unit
Repeater System
LTU
(compatible with
terrestrial LTU)
WTU
Down-stream
1FP
Up-stream
Repeater

25. The Number of Terminal Bay
Repeater System
LTU Bay
Cable
Qingdao
Taean
Repeaterless System
Twice !
Quigdao
Taean
New Station

26. Conclusion - Configuration for Repeater system and Repeaterless system
were presented.
- The three options of system
between Korea and China were shown.
- From the standpoint of the cable capacity and cost,
Repeater system is more attractive for the system
between Korea and China.