© Ciena Corporation
5
Increased Spectral Efficiency, More Capacity
Spectral efficiency: more bits, same fiber system, no forklift upgrade
Higher spectral efficiency
at 100G theoretically
possible
Spectral Efficiency
0
0.2
0.4
0.6
0.8
1
1.2
2.5G
10G
40G
100G
Bit Rate
Text Box: b/s/Hz
J. Zik
The challenge for carriers in DWDM networks is to provide more capacity over the same network for delivery of media rich services such as triple play or quadruple play, business services and the like.  This prevents or delays expensive network overbuilds.
IN order to do this, this requires single wavelength 100G networking for any network that requires transport> 40km.

Carriers will not use parallel lanes such as 10x10G or 4x25G since they offer little or no improvement in spectral efficiency (translates to network capacity) over 10G systems.   Notice that spectral efficiency improves as the bit rate increases.  This leads to more capacity over existing infrastructure to prevent overbuilds.  High spectral efficiency is one of the predominate tools that carriers need to deliver low revenue data traffic cost effectively.

NEIL,
Jim hands back to Neil: So what does a typical carrier installation look like today?

End slide 14:30