THE EFFECT OF DATA-EFFICIENT TRANSMISSION TECHNOLOGIES ON SUBMARINE - - PowerPoint PPT Presentation

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THE EFFECT OF DATA-EFFICIENT TRANSMISSION TECHNOLOGIES ON SUBMARINE CABLE SYSTEM OPERATING MODELS

Gavin Doyle

Cable and Wireless Worldwide

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Presenter Profile

Gavin Doyle is a Systems Engineer working for Cable & Wireless Worldwide. Gavin joined Cable & Wireless in 2005 as part of the Cable and Wireless graduate training scheme and joined the Submarine Cable Systems department in 2007. Since then he has worked

• n various cable systems including Maya-1,

DSCN, PanAm, Taino Carib, Apollo, EIG and

• WACS. He is a Prince2 Practitioner and also a

Member of the Institution of Engineering and Technology.

Gavin Doyle Email: gavin.doyle@cw.com Tel: +44 (0)1344 811874 Mobile Tel: +44 (0)7776 284991

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The evolving telecoms market

The trend in telecoms revenues over the last 10 years indicates:

Year Revenue (£bn )

• declining fixed voice

telephony use

• rising use of data

based services.

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Evolving telecoms operators

Telecoms operators are now adapting their networks to take advantage of:

• High profit margin data services
• Increasing volume of IP based traffic
• Increasing volume of consumer internet

traffic

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Design principles behind the next generation of terrestrial networks

• Based on data efficient IP-based transmission

technologies such as Ethernet.

• Incorporate network control and traffic

management at the higher levels of the network.

• Protection architecture is based on ‘mesh’

network.

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Typical design principles of submarine cable systems

• Assume traffic is mainly aggregates of traditional

voice channels and not ‘bursty’ data traffic.

• Are SDH based cable systems that need to be

capable of managing the traffic that it transports.

• Assume the SDH based cable system should

provide 1+1 protection paths to ensure high system availability.

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• Control of the submarine link is out-sourced to the
• perations and maintenance committee that own the

cable system, reducing the visibility and control that

• perators have over their own traffic.
• Capacity bottle-necks are caused by popular SDH

drop points.

• SDH protection schemes cause poor bandwidth

efficiency. The shortcomings of this approach are that:

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And even more importantly:

SDH based architectures are not an efficient way of handling data traffic.

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How can this situation be improved?

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Interim solutions

• Optical Transport Network (OTN G.872 and

G.709)

• Ethernet over SDH

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Optical Transport Network vs SDH

OTN Transponders Ethernet STM-n STM-n Ethernet Line SDH ADM SDH Transponders Line STM-n STM-n Ethernet Ethernet

OTN gives the network

• perator a greater

flexibility of client side interfaces to/from the SLTE with no need for intermediary ADMs.

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Advantages of OTN

• Can transmit various types of traffic across the

same infrastructure.

• Combines the reliability of SDH with the efficiency of

packet based transmission.

• Allows system management to be executed by the
• perator due to a transparent data channel for

network management data.

• Includes Forward Error Correction to allow users

to stretch their power budgets even further.

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OTN advantages

OTU-1 (2.7Gb/s) OPVC1-1 OTU-2 (10.7Gb/s) OPVC1-2 OPVC1-16 OPVC (155Mb/s)

OTN Multiplex Structure

• OTN also accommodates signal levels down to 155Mb/s

and also allows concatenation of these signal to form hybrid data-rate channels.

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Ethernet over SDH

Data-stream inserted into SDH layer Asynchronous Ethernet frames

1 2 3 4 1 2 3 4 5 5 1 2 3 4 5

Data transported on separate SDH channels using Virtual Concatenation. Framed into synchronous data-stream

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Assuming the trend in telecoms continues towards higher volumes of data traffic What architecture for submarine cable systems would best accommodate this traffic?

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10Gb/s Ethernet access would not be of any use to a small investor that currently requires

• nly 2 x STM-16s.

The use of IP-VPNs may be a solution to this.

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The IP-VPN model

VPN 1 VPN 2 VPN 5 VPN 1 VPN 4 VPN 6 VPN 5 VPN 6 VPN 2 VPN 3 VPN 4

Ethernet link

IP Router/Switch IP Router/Switch IP Router/Switch IP Router/Switch

Ethernet link Ethernet link Ethernet link

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IP-VPN applied to submarine cable systems

Ethernet WAN/LAN PHY or OTN Transponders Line Client Ethernet VLAN Ports

IP switch/router

Ethernet WAN/LAN PHY or OTN Transponders Line Client Ethernet VLAN Ports

IP switch/router

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IP-VPN Class of Service (CoS)

Premium Enhanced Standard Premium Enhanced Standard Enhanced Standard

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IP-VPN design in consortium system

• Each operator is assigned a separate VPN on the

network

• Minimum Investment Unit is the lowest access

bandwidth possible on the client side VPN ports.

• This VPN bandwidth is guaranteed using CoS to

prioritise traffic.

• Each VPN bandwidth can exceed the guaranteed

maximum when excess capacity exists in other VPNs.

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To summarise

• Telecoms market is evolving towards more data-

centric services.

• Terrestrial networks have evolved or are evolving to

accommodate increased levels of data.

• The submarine cable system model is still based on

data-inefficient synchronous transmission technology.

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In conclusion

• OTN and Ethernet over SDH can improve the data-

efficiency of submarine cable systems.

• OTN and Ethernet can allow terrestrial operators to

use the submarine cable system as a transparent transmission path.

• An IP-VPN (CoS) based system could be

implemented on submarine cable systems to handle predominately data based transmission.

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In conclusion

An Ethernet WAN PHY or IP-VPN based system would allow:

• Terrestrial operators to incorporate the submarine

cable link into their terrestrial ‘mesh’ networks.

• Client port bandwidth can be upgraded remotely with

no capital costs.

• MIU bandwidth can be exceeded if sufficient over

capacity is available

2010

Pacifico Convention Plaza Yokohama & InterContinental The Grand Yokohama 11 ~ 14 May 2010 www.suboptic.org

enabling the next generation of networks & services

The 7th International Conference & Convention

• n Undersea Telecommunications

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