US Patent 7836208 Dedicated redundant links in a communicaton system

The invention relates to active star coupler based network handling of redundancy in the physical layer by transmitting a message to both regular and redundant links. In an error free case, the message is forwarded by the regular interface, while the redundant link, is blocked. Each interface is equipped with link failure detection logic. If a link failure is detected, an incoming message is blocked and the affected interface controls the interface connected to the redundant link to take over message forwarding. If the link recovers, the regular interface takes over forwarding responsibility and the redundant link is disabled.