| 摘要 |
A packet switching network (100) comprises switching nodes (220-222, 230-232, 240-242, 250-252, 260-262, and 270-272) residing on circuit packs (101-104), that are interconnected by packet signal transmission links (110-119, 140-149, 150-159, and 180-189) carrying multiplexed pulse-width modulated signals (450) each representing three bits. A link (112) incoming to a pack (101) connects to an input port (2821) of a demultiplexer (282), whose output ports (2822-2824) are coupled to packet inputs (2401, 2411, 2421) of three nodes (240-242). The incoming signal stream is demultiplexed into three serial signal substreams. Each substream is transmitted to a node for switching. A link (122) outgoing from a pack (101) connects to an output port (2871) of a multiplexer (287) whose input ports (2872-2874) are coupled to the packet outputs (2703, 2713, 2723) of three nodes (270-272). The three incoming serial signal substreams are multiplexed into a signal stream that is transmitted on the link. For multiplexed signals representing the bits of a single packet, (FIGS. 2a-c), the acknowledgment output (2405) of one node (240) coupled to a demultiplexer (282) is connected to the incoming link (112) and the acknowledgment input (2707, 2717, 2727) of each node (270-272) coupled to a multiplexer (287) is connected directly to the outgoing link (122). For multiplexed signals representing the bits of three packets, (FIGS. 3a-c), acknowledgment outputs (2405, 2415, 2425) of the nodes (240-242) that are coupled to a demultiplexer (282) are coupled through a multiplexer (294) to the incoming link (112). Acknowledgment inputs (2707, 2717, 2727) of the nodes (270-272) that are coupled to a multiplexer (287) are coupled through a demultiplexer (291) to the outgoing link (122). Coupling of a packet and acknowledgment input and output pair to a demultiplexer and a multiplexer is made by a lock (246) which alternately makes one connection while it breaks the other connection. The locks that connect to a multiplexer and demultiplexer pair operate in unison. |
