EMC considerations for telecommunications switching centres

The authors address the increasing impact of electromagnetic compatibility (EMC) requirements on the design of modern telecommunications switching equipment. Following a review of the environmental factors which have given rise to the increase of work on EMC, the impending European EMC Directive is introduced and compared with the legislative requirements in the US. The specific problems associated with the EMC characterization and formal testing of large distributed telecommunications installations are discussed, drawing on examples of various system configurations to illustrate particular aspects. A proposed method of testing is presented which offers a controlled and repeatable approach to RF emission and immunity testing within a total quality environment, enabling system-level emission characteristics to be determined, and the effect of subsequent product updates and enhancements to be predicted over a normal installation life of 20 years