Patent ID: 7409566
Filing Date: 2008-08-05
Classification: G06F

Abstract:
1. A method of terminating power supplied to a remote device through a network cable, the method comprising: monitoring a hardware-level signal received from the remote device over the network cable; detecting that the remote device has been disconnected from the network cable by failing to sense voltage transitions in the hardware-level signal received from the remote device; and in response to detecting that the remote device has been disconnected from the network cable, terminating power supplied through the network cable, wherein: the monitoring comprises continually monitoring the network cable for the presence of a data communications signal sent by the remote device when attached to the network cable, the communications signal being present on the network cable even when the remote device is not actively transmitting data on the network cable; and further comprising: detecting, after terminating power supplied to the remote device through the network cable, that the remote device has been re-connected to the network cable by detecting the presence of the data communications signal sent by the remote device; and in response to detecting that the remote device has been re-connected to the network cable, supplying power to the remote device through the network cable, and wherein the data communications signal is encoded according to a code such that a detectable voltage transition of the coded data communications signal is guaranteed to occur over no more than a small number of signaling intervals even when the remote device is not transmitting data.