Characterisation of central office main distribution frame for ADSL-DMT services

This work presents a study for characterisation of the central offices main distribution frame (MDF) to provide services via the Internet, through asymmetric digital subscriber line ADSL technology, using DMT - discrete multitone modulation. The study is focused on the channel´s loss of transmission capacity as a result of noise level, length of metallic wire cables, the wires´ gauge and the number of bridge taps. These parameters are analysed through mathematical models, simulations carried out within a laboratory environment, and later, in a real network in the city of Sa˜o Paulo, Brazil. The results obtained present a relevant contribution for Internet service providers, offering elements for the dimensioning of equipment in the selection of proper lines, selection of service areas and restriction of maximum rates offered, recovery of existing lines for provision of the service and economic feasibility studies.