For planning wireless communication systems the noise levels outside buildings have been used. The ITU (International Telecommunication Union) man-made noise levels are based on measurements performed in the 1970s. Measurements carried out since then showed that the noise caused by ignition systems reduced, but man-made noise in business areas and city centers increased. But the interference scenario changed: from analog communication systems in relatively free space to digital systems in living areas, often semi-enclosed such as offices, industrial production areas, and even cars and trains. Measurements in these semi-enclosed environments show a much higher, up to 60dB, manmade noise level. The higher noise level is not only due to a shorter distance to the source of emission, but mainly due to mistakenly assumption that compliance with a harmonized product standard is sufficient evidence of compliance with the European EMC directive. This is an incorrect and a wrong assumption. The EMC directive gives essential requirements to comply with. The use of harmonized product standards only gives a presumption of conformity. In a court case in a dispute on EMC of an electrical wheelchair, the key reference was the essential requirements and not the harmonized product standards. Several product standards have been developed with relaxed, or sometimes even no requirements. Some allow unlimited emission levels while others restricted the frequency range. These standards, although harmonized, are not in line with the essential protection requirements of the EMC directive.
|Number of pages||6|
|Journal||IEEE Electromagnetic Compatibility Society newsletter|
|Publication status||Published - Aug 2010|