Posts From the monthly archives: "December 2012"

Polarisation multiplexing is commonly used in 100Gb/s line side transmission as a method to increase the bit rate over the line without increasing the transmitted symbol rate. Using polarisation controllers it is possible to generate two perpendicular polarised optical signals on the same wavelength for transmission through a single fibre. As two separate signals…(Read More)

There are a number of challenges to achieving 100Gb/s optical transmission rates using the technologies that have been deployed at 10Gb/s and even 40Gb/s. Using traditional transmission technologies such as NRZ modulation on the line will result in very poor spectral efficiency and a 100G signal using NRZ would not fit into…(Read More)

The alignment marker is used for the identification of the PCS lanes. They allow the receiving network equipment to identify the lanes as they are received so that that they can be re-ordered. So what is an alignment marker? An alignment marker is a single 66 bit block that is inserted into the stream…(Read More)

100G testing plans must include specific attention to the physical interface. The CFP interface is no longer a single transmitter and receiver pair that can simply be checked with simple tests such as a basic optical power measurement or receiver sensitivity measurement. Utilising multiple optical lanes simultaneously makes testing the interface more complex and also…(Read More)

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