With the appearance xDSL technology, that uses the existent copper cables, became possible the high-speed data communications in the subscriber lines. The xDSL technologies offer advantages as the reduced investment, since it uses the existent metallic nets as transmission. For use of those nets, systems were developed with bandwidth that is going from some kHz to dozens of MHz.
However, as the existent metallic nets have been used mainly for voice services, with bandwidth from 0 to 4 kHz, many problems already begin to appear, as the line qualification needs for the broadband sign and minimization crosstalk interference.
Another aspect is that the existent metallic cables were projected to operate 100% in frequencies up to 1MHz, once they were for voice transmission. Therefore with the operation frequency increase, the cables are not 100% reliable. The studies show that for current transmission taxes in ADSL, only 30 to 40% of the cables can be used, and depending on the transmission net not even that.
A more important aspect than the operation frequency in the existent cables, are the factors of the system unbalance, or crosstalk (digital loops mistakes). The crosstalk is NEXT - near end crosstalk and FEXT - far end crosstalk.
Due to all those factors, we understood that current nets supporting a small density in xDSL systems, and in a brief future, with the density increase they will no more support those services, doing with that physical middle of transmission is the communications system bottle-neck. So Nexans developed product for those configurations, with similar Data production process (UTP).
These cables can be well installed at lashed underground telecom networks, supporting a wide range of enterprise or subscriber applications, such as integrated voice, data and video to the office desk or home. Nexans Brazil has developed families of "last mile" copper cable solutions, allowing capacities up to 200 pairs.