The EM environment and xDSL

The onset of the 'datawave' has seen an explosion in data traffic over the access network (primarily arising from Internet use). This growth has been matched by the demand for progressively higher data rate services. To meet this objective cost effectively, it is necessary to exploit sophisticated and innovative broadband digital transmission schemes that utilise the existing local loop (e.g. xDSL). These involve the use of signalling at frequencies above the traditional voice band services that extend into the LF, MF and HF radio bands. This paper has demonstrated that wire line systems operating at these frequencies have the potential to cause limited interference to radio communication and to broadcast services at the fringe of service area locations. It has been practically demonstrated that ADSL can be deployed in BT's access network, without necessarily causing interference to broadcast reception. MPT1570, a UK standard that would define test methods and limits for measuring radiated emissions from wire line transmission systems, is currently in development.