What does cable modem SNR measure?

The measurement of SNR, or Signal-to-Noise Ratio, is critical in understanding the performance of a cable modem. SNR assesses the ratio of the desired signal (which is important for the functioning of the modem) to the background noise that can interfere with that signal. A higher SNR indicates a clearer signal with less noise interference, which is essential for good internet connectivity and speed.

In practical terms, if the SNR is too low, it may lead to issues such as intermittent connectivity, slower speeds, or even complete service disruptions. This makes measuring SNR vital for technicians who troubleshoot and optimize cable modem performance.

While the other options touch on aspects related to a cable modem's performance or installation, they do not accurately represent what SNR specifically measures. The power level of the modem, the quality of the installation, and the distance to the nearest node are important factors in overall system performance but do not directly define the relationship between the signal and background noise, which is precisely what SNR encapsulates.