ITU sets new 'closure' standards for fibre-optics

- Standards pave the way for less costly networks

9 May 2003 Geneva, Switzerland--The ITU reports that it has has completed work that smoothes the way for a vital component of next generation networks.

The new set of performance measurements will make it easier for service providers to deploy Sealed Fibre Optics and Passive node elements in next generation fibre optic networks. It will also mean that manufacturers will be able to speed-up their development cycles, resulting in lower prices. The standards give special attention to network stability and future adaptability, key concerns for all telecom operators.

The standards known as ITU-T Recommendations L.13 and L.51, form the first international performance standards for fibre-optic closures in the world. A fibre-optic closure is equipment that protects fibre optic components from the elements.

The standards will allow network operators to more accurately benchmark optical node products. While manufacturers, will find conformance testing simplified and the process of tendering and ordering easier, where the standards can be specified in tenders.

The globally applicable standards were conceived as a practical tool for generating performance specifications for sealed optical closures in outside plant, in response to industry demand. A complete basic test plan, together with summary checklist, make them the ultimate tool for anyone involved in the development and purchasing of optical closures.

Francesco Montalti, President of the ITU's Study Group 6, said, "In the past, several attempts were made to develop an internationally acceptable performance standard for optical closures, without success.

"ITU-T Study Group 6, leveraging the knowledge and years of experience of member operators and manufacturers around the globe, is the first organisation to do so. We also have to thank the IEC SC86B group for their close cooperation."

The use of Recommendations L.13 and L.51 in the deployment of optical networks will provide a more consistent level of quality resulting in more stable and future proof networks. Ultimately this will help maintain the standards of quality needed by the most recent transmission equipment and reduce outages at passive nodes.

ITU-T Rec. L.51 contains a summary of parameters that are relevant for the performance of optical nodes. It describes environmental classes and installation conditions, as well as circuit separation and transient losses during network maintenance activities.

It contains the basic principles and parameters to obtain consistent node performance throughout the network. In the appendices, one can find detailed descriptions of application environments, how to build optical test samples and how to test optical stability when accessing a product.

ITU-T Rec. L.13, focusing on sealed optical closures for outside plant, has been revised according to L.51. The Recommendation provides a complete performance specification and test plan.

The user has the flexibility to select the applicable installation environment, the desired level of optical stability and a level of circuit separation. It is also possible to modify the basic environmental test settings according to specific local needs by specifying additional requirements.

A similar ITU-T Recommendation on the performance of Optical Distribution frames (ODF) should be ready by the end of 2003. Amendments have also been made to Recs G.652 and G.655 on fibres and cables for compatibility with L.13.