Patent ID: 7412167

Claim:
A system for limiting a data transmission capacity on a data transmission path on at least one glass fiber line, comprising: at least one transmitting unit; at least one receiving unit, wherein the data transmission path is arranged between the at least one transmitting unit and the at least one receiving unit for interchanging an optical transmission signal, at least one limiting unit, inserted between the at least one transmitting unit and the at least one receiving unit analyzing the optical transmission signal and limiting the transmission capacity on a user-related basis; the limiting unit comprising: a coupling unit for outputting a part of the optical transmission signal, which is carried on the glass fiber line; an optical receiver for converting the outputted part of the optical transmission signal into an electrical transmission signal; a bit rate determining device for detecting a bit rate of the electrical transmission signal, wherein the bit rate determining device is one of an edge counter and clock recovery circuit; a comparator for comparing the bit rate with a predetermined maximum bit rate; and a module, which interrupts or disturbs the optical transmission signal being transmitted to the receiving unit by said optical transmission signal in accordance with a result outputted from the comparator if the bit rate exceeds the predetermined maximum value.