了解G-G的DWDM-OTN.ppt

This shows why and how IEC interpolation fails. * * * * * * Lets start our PMD discussion with some PMD description. What is exactly PMD. Mainly, PMD is due to delays that will experiment the different Polarization mode traveling in the fibers. These delay are due to a speed difference that origins from the fiber birefringence. For those of you that are less familiar with fiber design, fiber birefringence is the representation of the index of refraction changes within the core and along the fiber. To well understand PMD there is a couple of key concept that needs to be understand. These concept are the DGD, the PSP and the SOP. We will try to image these concept with practical example in the next few slides * * * * * This slide presents a regional mesh network. The use case is to proof test all the unused fiber in existing cable in preparation of 10Gbps upgrades that will happens at all sites and 40Gbps upgrades that will happen in three major sites on the periphery of the mesh network. This mesh network is built around 9 nodes connected by 15 fiber-optic cable spans with many fiber-optic strands inside those cables. The question is ‘’what is the most productive CD/PMD testing method possible’’. The answer is that all the unused fiber-optic strands in these 15 cables spans can be tested from only 4 testing points, using the FTB-5500B and the FTB-5800 at one point and the FTB-5700 at 3 testing points. * * FTB-5600 allows to locate fiber section that are large contributors to the total PMD of a link and enables isolating and repairing only the worst PMD sections. This scenario represents the most cost-effective upgrade of a fiber network. * THIS RS-POTDR was used in a field trial to measure the distributed PMD of buried fibers in the network of Deutsche Telekom Presentation is focused on the results * * * * * The function of the receiver is to provide the demodulator with the cleanest electrical signal it can extract from the optical signal it receives. Therefor