Patent ID: 7246368

Claim:
A method of testing a cable network, using one or more cable modems on the cable network, while allowing live data traffic at an original frequency, the method comprising: (a) identifying a group of time increments, associated with live data transmission, during which cable modems on the network are not scheduled to transmit data; (b) instructing a first one of the one or more cable modems (i) to send a first test signal of a first frequency at a first power during a first one of the time increments, and (ii) to send the first test signal while the first cable modem is on line and engaged in live data transmission at the original frequency; (c) measuring the power of the first test signal received at a specified location on the cable network; (d) instructing the first cable modem (i) to send a second test signal of a second frequency during an available time increment, and (ii) to send the second test signal while the first cable modem is on line and engaged in live data transmission at the original frequency; (e) measuring the power of the second test signal received at the specified location on the cable network; and (f) recording a power versus frequency spectrum of the first modem at at least the first and second frequencies, wherein the first and second frequencies belong to different transmission channels.