Polarisation Mode Dispersion (PMD) is an effect in optical fibres that can limit their ability to support very high data rate (10Gb/s+) transmission over long distances. Understanding the PMD characteristics of fibres in the network is important to many network operators, especially when it comes to providing dark fibres to other service providers. Often the only way to determine the PMD characteristics, particularly of older fibres, is to measure them. There may not have been PMD specifications in place when the original cables were installed. However there are some issues involved in testing the PMD of fibres in aerial cables that may move during the measurement. During recent discussions on PMD measurement standardisation in the TIA (as well as in IEC & ITU), OTT offered to organise a PMD measurement intercomparison.
In August a team of engineers from Mobily, a Saudi Arabian mobile network operator, travelled to the UK to take the Certified Optical Network Engineer course.
In commemoration of the Centenary of the IEC (International Electrotechnical Commission) the 1906 Awards were set up to recognise individuals who have made exceptional contributions to the development of International Standards. Each year, up to five 1906 awards can be made by each Technical Committee. Richard Ednay is one of those nominated this year for his work on IEC TC86 that deals with fibre optics.
OTT are giving you the opportunity to prove that you really understand Next Generation Optical Networks, by becoming a Certified Optical Network Engineer (CONE).
The new 5-day CONE training and certification has developed from the heritage of OTT's popular "Understanding Next Generation Optical Networks" programme, first launched in the early stages of telecoms boom time, which had a unique complete systems perspective. That programme has been updated regularly and run as a company course for various telecoms companies and end users. The new extended CONE certification which is focussed on long haul core networks will now be available as a public course from January 2008. It is rigorously assessed by a closed book examination as well as a practical assignment based on real case study material, and is destined to set the standard for the professional optical network engineer.
The Nato Allied Joint Force Command in Brunssum is the home of some of Nato's top communications infrastructure experts. In September a team of engineers all successfully completed the Certified Fibre Characterisation Engineer (CFCE) training programme at OTT in Skipton.
Optical Technology Training Ltd. is extending its range of world leading training courses to include a technician level certification scheme for fibre characterisation. Building on the success of the more advanced CFCE (Certified Fibre Characterisation Engineer) programme this technician level course is very practical with lots of hands-on experience on actually performing fibre characterisation tasks, including insertion loss, return loss & OTDR testing, as well as carrying out chromatic dispersion, polarisation mode dispersion and spectral attenuation measurements.
OTT has extended its standards activities by joining ITU-T as an Associate Member. The ITU (International Telecommunications Union) is the world's authority on all aspects of telecommunication systems standardisation and its recommendations ensure that the world's communications systems can all interoperate.
The Optical Networking Lab at JDSU's facility in Eatontown, New Jersey provided the latest Certified Fiber Characterization Engineer (CFCE) training program. This world-leading certification program provides the knowledge and skills needed to carry out comprehensive characterization of optical fiber links and to analyze the results to assess the quality of the infrastructure and the ability of the link to support new high speed applications including 10 & 40Gb/s OTN, 10Gb/s Ethernet, extended wavelength DWDM and CWDM systems.
By Richard Ednay
One of the biggest myths surrounding polarization mode dispersion (PMD) is that it is only an issue with old fibers installed more than about 10 years ago. However, experience shows that there can be problems with cables that were installed during the optical boom when the established, reputable fiber manufacturers were unable to meet the demand for quality fiber. Poor-quality fiber that would otherwise have been scrapped found its way onto the market; fiber was also procured from other sources around the world whose fiber manufacturing processes and procedures were not as well controlled as those of the major vendors. In fact, the record for the worst fiber this writer has ever tested comes from this era: Can anyone beat a figure of 27 psec/√km for the PMD coefficient of an installed fiber link?