| 摘要 |
<p>In a cable modem system a method is provided for continuously monitoring the upstream channel to assess what unused upstream channels will better support data communication in the event that an active upstream channel degrades, with monitoring of the upstream path by using passive or unused channels not impacting active data transfer. In one embodiment, a single spectrum assessment receiver (20) polls cable modems (24) at various taps (16) and has the selected modem retune itself to an unused channel and transmit a reference signal back to the spectrum assessment receiver (20). An analysis is made and an impaired active channel is identified to ascertain if it has degraded to an unacceptable level. If so, it is switched or hopped to this unused channel if by switching an improvement can be realized. Polling selects the modem at the worst performing tap and ascertaining after one or more retunes which unused channel is best.</p> |
