(LowerLayers.pdf 58页)
- (D|C)WDM = Dense/Coarse Wave Division Multiplexing
致密型 / 稀疏型波分复用 - 使用不同颜色的光在光纤中传输信息 (你也可以说是用不同的lambda波长..
- 原本相邻频道(channels)间间隔0.8nm
- 现在可以是0.4nm或0.2nm
- 相邻频道间隔20nm
(20nm difference between adjacent channels)
- 每个频道可以承载不同的traffic (ATM, ethernet, SDH, 啥都可以)
- 未来的趋势就是使用WDM承载以太网,一根WDM里面承载不同的以太网
Increasingly, ethernet straight over WDM is the way telcos are going, with the assumption that most ethernet will just be carrying IP.