| 摘要 |
A system for the bi-directional routing of data messages over a CATV network is disclosed. In the CATV network, subscribers are coupled through taps (20) to service lines (18) extending from a service site (16). Data messages generated by a subscriber, which do not have a destination address corresponding to one of the service lines (18) extending from the service site (16) for the message generating subscriber, are provided to the next higher level of the CATV network over a receive cable (30). Each service site (16) has its own receive cable (30) which may be coupled to a distribution hub (14) or a headend (12). The receive cables (30) isolate the data messages of each service site (16) from the data messages sent by the other service sites (16). At the distribution hub (14) and headend (12), a switch is provided for each receive cable (30) and the switches are coupled to one another. At a distribution hub (14), data messages having a destination address corresponding to one of the other switches at the hub (14) are routed to the corresponding switch. Messages so received by a switch at a distribution hub (14) are provided through transmission cable (28) to the next lower network level coupled to the switch. Destination addresses in data messages not recognized by a switch at a distribution hub (14) are coupled to a receive cable (30) for transmission to the next higher level in the network. At the highest level of the network, a headend (12) is provided which includes a switch for each receive cable (30) coupled to the headend (12) and each switch at the headend (12) is coupled to the other switches for the routing of data messages as performed at the distribution hub (14). The system preferably includes frequency stackers and destackers so data messages from each service (18) line may be placed on separate data channels to further enhance message isolation and reduce message traffic in the spectrum of a transmission or receive cable.
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