Hybrid photonic-electronic subscriber access unit for connecting optical subscriber lines to an asynchronous transfer mode telecommunication network

Claim 1

A hybrid photonic-electronic subscriber access unit for connecting subscriber lines to an asynchronous transfer mode telecommunication network comprising a plurality of hybrid photonic-electronic subscriber access units, said subscriber lines conveying data in the form of cells including a header containing routing information, said access unit comprising: an asynchronous transfer mode switching network (5); a plurality of subscriber line interface circuits (1, 6) connected to respective subscriber lines; at least one concentrator (2, 7) connecting the switching network (5) to the subscriber line interface circuits (1, 6); and said subscriber access unit being characterized in that each of the subscriber line interface circuits (1, 6) comprises: electronic means (23) for discriminating between empty cells, signalling cells and maintenance cells in a stream of cells from the subscriber lines; electronic means (24) for translating routing information contained in the headers of the cells from the subscriber lines and writing tile translated information into said headers; electronic means (25) for adding a routing label to the cells from the subscriber lines; and electronic means (26) for monitoring the bit rate of the cells from the subscriber lines; and in that said concentrator (2, 7) comprises: electronic means (34) for statistically time-division multiplexing the cells from the subscriber line interface circuits (1); photonic means (38) for wavelength-division multiplexing the cells output by the electronic statistical time-division multiplexing means, and for multiplying the bit rate of the cells that have been wavelength-division multiplexed; and photonic means (40) for time-division multiplexing the cells whose bit rate has been multiplied.