Abstract: A novel mechanism for sharing filter taps across a plurality of interference cancellers. Each interference canceller may be directed to impairment, such as Ethernet impairments, including Ethernet 1000Base-T impairments. Various interference impairments include echo cancellation, NEXT cancellation and/or other interference detection or cancellation, etc. The hardware requirements of the interference impairment cancellers are reduced by sharing filter taps among the cancellers. In a first embodiment, the taps from a unified filter tap bank are shared across all the interference impairment cancellers for all four channels and over all ports. In a second embodiment, a portion of the taps of each filter are shared wherein each canceller comprises a fixed filter tap portion and a shared filter tap portion. A tap allocation algorithm assigns taps to those cancellers that need them the most. A canceller configuration is selected that yields maximal interference mitigation and the taps are allocated accordingly.

Abstract: A novel mechanism for 1000BASE-T network adapters to detect and resolve connections for cables that are either fully aligned, fully crossed or semi-crossed. The mechanism is applicable to adapters in either master or slave modes, and operates with cables that either have channels A and B aligned with channels C and D crossed or channels A and B crossed and channels C and D aligned. Cables of different configurations can be switched at any time without impacting network operation. In addition, a mechanism for 1000BASE-T adapters to support multiple scrambling methods between the adapter and its link partner is described.

Abstract: A novel mechanism for detecting the presence of powered devices over a network. A unique, infinite pseudo-random sequence of pulses are generated and transmitted over the network to the link partner attached to the other end of the cable. At each time unit, the PSE decides whether or not to transmit a pulse at that time. Thus, the pulses generated have pseudo-random inter-pulse delays between them. In addition, each pulse is pseudo-randomly selected to have either positive or negative polarity. If the link partner is a powered device it will be in loopback mode and the transmitted pulses will be looped back to the transmitter (i.e. the PSE). The PSE, at each time unit regardless of whether or not a pulse was transmitted, opens a search window in which it listens to the RX line for the appropriate expected behavior. If a pulse was transmitted, the PSE expects to see a pulse looped back. Similarly, if no pulse was transmitted, the PSE does not expect to receive a signal during the search window.

Abstract: A novel mechanism for sharing filter taps across a plurality of interference cancellers. Each interference canceller may be directed to impairment, such as Ethernet impairments, including Ethernet 1000Base-T impairments. Various interference impairments include echo cancellation, NEXT cancellation and/or other interference detection or cancellation, etc. The hardware requirements of the interference impairment cancellers are reduced by sharing filter taps among the cancellers. In a first embodiment, the taps from a unified filter tap bank are shared across all the interference impairment cancellers for all four channels and over all ports. In a second embodiment, a portion of the taps of each filter are shared wherein each canceller comprises a fixed filter tap portion and a shared filter tap portion. A tap allocation algorithm assigns taps to those cancellers that need them the most. A canceller configuration is selected that yields maximal interference mitigation and the taps are allocated accordingly.

Abstract: A novel mechanism for detecting the presence of powered devices over a network. A unique, infinite pseudo-random sequence of pulses are generated and transmitted over the network to the link partner attached to the other end of the cable. At each time unit, the PSE decides whether or not to transmit a pulse at that time. Thus, the pulses generated have pseudo-random inter-pulse delays between them. In addition, each pulse is pseudo-randomly selected to have either positive or negative polarity. If the link partner is a powered device it will be in loopback mode and the transmitted pulses will be looped back to the transmitter (i.e. the PSE). The PSE, at each time unit regardless of whether or not a pulse was transmitted, opens a search window in which it listens to the RX line for the appropriate expected behavior. If a pulse was transmitted, the PSE expects to see a pulse looped back. Similarly, if no pulse was transmitted, the PSE does not expect to receive a signal during the search window.