A network isolation system may include a network interface, a power level detector, and a processor. The network interface may be configured to receive signals over channels, where the signals include at least one local network signal, e.g. a signal originating on a local network, and at least one non-local network signal, e.g. a signal originating on a non-local network. The power level detector may be configured to determine attenuation values of the received signals. The signal processor may be configured to discard a first signal and reallocate the channel over which the first signal was received, without processing the first signal in a frequency domain, when the attenuation value of the first signal fails to satisfy a signal threshold. In one or more implementations, the signal threshold may differentiate the local network signal from the non-local network signal based at least in part on the determined attenuation values.