| 摘要 |
When broadcast is executed in an ATM mode, a subscriber is assigned a path and a channel as information by a central controller of a switching unit, and the information is added to a cell to be transmitted to the switching unit through a subscriber line. The switching unit comprises the central controller, a tag information adder, and a self-routing switch. The self-routing switch comprises a plurality of input lines and output lines, and unit switches provided for each input line corresponding to each of the output lines. The tag information adder adds routing information for the switch to a cell to be transmitted to the self-routing switching. The routing information comprises a set of bits corresponding to each output line, and the tag information adder adds to the cell the routing information in which a bit corresponding to an output line for transmitting the cell is set to a predetermined logical value. In executing the broadcast, a plurality of bits corresponding to a plurality of output lines are set to a predetermined logical value. The self-routing switch analyzes the routing information of the cell received by each unit switch, and outputs the cell to the output line if the bit corresponding to a unit switch is set to a predetermined logical value. If a plurality of bits of routing information are set to a predetermined value, the cell is outputted from a plurality of output lines, thus enabling the broadcast. |
