Submarine Cable System - Focusing on the Link between China & Korea - Noriyuki Takeda and Junji Matsuda KDDI Submarine Cable Systems Inc. (KDDI-SCS) May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

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 May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

Use Pursuant to Company Instructions 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 May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

Use Pursuant to Company Instructions 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 May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

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 May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

Use Pursuant to Company Instructions 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 May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

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 May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

Use Pursuant to Company Instructions What is Maximum Number of Wavelength? 10Gbit/s per wavelength Maximum Number of Wavelength Repeater System KJCN Repeaterless System System Length [km] May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

Use Pursuant to Company Instructions Why is the Number of l Limited in Repeaterless System? Repeater 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 May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

Use Pursuant to Company Instructions Upgrade Strategy - Repeater system - Repeaterless system Cable l Increasing the # FP (Use the dark fibers) Increasing the # wavelength > 3T bit/s / cable May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

Use Pursuant to Company Instructions 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 May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

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 May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

Use Pursuant to Company Instructions 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 May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

Use Pursuant to Company Instructions Key Technologies for Repeater System Repeater 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 May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

Use Pursuant to Company Instructions Repeater System - 10Gbit/s x 200WDM, 9200km - 200WDM 9,200km 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 : 10-9 with super FEC Output of Transmitter After 9,200km Transmission May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

Use Pursuant to Company Instructions 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 May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

Key Factors to Realize the System - Demand - Feasibility of transmission technologies - Location of cable landing station - Network configuration - Cost May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

Comparison of New and Existing Cable Landing Station Using the Existing Stations is preferable ! May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

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 May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

Network Configuration Repeater System Option 1 Repeaterless System Option 2 New Station Taean : Exist. Repeaterless System + Backhaul System Option 3 Qingdao : Exist. May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

Use Pursuant to Company Instructions Conditions for Cost Estimation Initial After Upgrade Note: 5 Repeaters are assumed in Repeater system (Option 1). May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

Cost for Initial Investment Price(M$) Initial May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

Use Pursuant to Company Instructions Cost for Upgrade Price(M$) After Upgrade (Ultimate) Initial May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

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 May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

The Number of Terminal Bay Repeater System LTU Bay Cable Qingdao Taean Repeaterless System Twice ! Quigdao Taean New Station May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

Use Pursuant to Company Instructions 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. May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions

Use Pursuant to Company Instructions Please visit out web site! KDDI-SCS Home page : http//www.kddiscs.co.jp N.Takeda (Technical) : ntakeda@kddiscs.co.jp J.Matsuda (Commercial) : matsuda@kddiscs.co.jp Thank you! May 25, 2002 KDDI-SCS Proprietary Use Pursuant to Company Instructions