| 摘要 |
<p>A method and apparatus for selecting time slots on selected lines on a network has particular utility for selecting idle time slots for a signal path between selected input and output highways in a network of highways in a telephone system. In the method a status list of selectable, idle time slots on a selected output highway is successively examined to identify each of the output highway idle time slots. A crosspoint between the highways is then closed during the time slot identified as idle to establish a signal path between the selected highways. Each selectable, idle time slot on only the input highway has an encoded signal or illegal word. If the input highway time slot during which the signal path is established as idle, the illegal ???d is carried from the input highway through the crosspoint to the output highway. An illegal word detector on the output highway detects the illegal word for selecting the idle time slots. In the apparatus a memory device successively identifies the busy or idle status of time slots on the selected output highway. A crosspoint closes a signal path between the input and output highways during the output highway time slot identified as idle. An illegal word detector on the output highway looks for an illegal word carried from an idle input highway time slot through the crosspoint to the output highway. When an illegal word is detected, the idle time slot and thus an idle path through the time division multiplexed network has been found.</p> |
