Optical line systems

This online course describes the capabilities, components and operation of the high capacity optical links that provide interconnections in telecommunications networks.

Topics covered by the course include the principles and applications of optical amplifiers, the characteristics and capabilities of various line interfaces (including SDH and Ethernet) and the principles and applications of wavelength division multiplexing (WDM). The principles and benefits of coherent detection and its role in 100 Gbit/s links are also discussed.

By the end of this course you will be able to:

• describe the role of Optical Line Terminal Equipment (OLTE).
• describe the principles and applications of optical amplifiers as repeaters, power boosters and pre-amplifiers.
• describe the characteristics of STM-1 to STM-64 optical interfaces as recommended by the ITU for SDH networks.
• describe the characteristics and applications of various types of singlemode optical fibre.
• describe and compare the capabilities of the Ethernet interfaces specified by the IEEE for long-haul optical links.
• compare the facilities, capabilities and applications of ITU recommended SDH links and IEEE Ethernet links.
• describe the principles and applications of the various forms of wavelength division multiplexing (WDM) inc. wideband WDM, narrowband WDM, Coarse WDM (CWDM) and Dense WDM (DWDM).
• describe and compare the advantages of the various methods of increasing the capacity of a link with reference to SDM, TDM and WDM.
• describe methods of reducing the effects of dispersion on high bit rate optical links.
• explain the limitations of on-off keying and direct detection
• describe the principles and benefits of phase shift keying and polarisation multiplexing.
• describe the principles and benefits of coherent detection and its role in 100 Gbit/s links.