CATV NETWORK INTERFACE UNIT WITH BANDPLAN DETECTION ON DOWNSTREAM SIGNALS

摘要

One exemplary embodiment is directed to a network interface unit (NIU) that comprises a network connector configured to receive signals from and send signals to a cable television (CATV) headend. The NIU further comprises a first diplexer comprising a first high pass filter configured for a first downstream radio frequency (RF) band and a first low pass filter configured for a corresponding first upstream RF band. The NIU further comprises a second diplexer comprising a second high pass filter configured for a second downstream RF band and a second low pass filter configured for a corresponding second upstream RF band. The NIU further comprises a cable modem port configured to output downstream RF signals to a cable modem and to receive upstream signals from the cable modem. The NR7 further comprises a coupling device configured to couple at least one of the first diplexer or the second diplexer to the cable modem port. The NIU further comprises a switch configured to switch between a first state and a second state, the first state coupling the network connector to the first diplexer and the second state coupling the network connector to the second diplexer. The NIU further comprises a control circuit coupled to the network connector and the switch, the control circuit configured to detect when a broadband trigger signal is present at a predetermined frequency spectrum within the first downstream RF band. When the broadband trigger signal is not detected, the detection circuit causes the switch to switch from the first state to the second state. Other embodiments are disclosed.