Method and Apparatus for Quick-Switch Fault Tolerant Backup Channel

In a network environment, the Quality of Service becomes an important issue particularly for applications involved with real-time multimedia streaming. Any transmission failure may cause service disruption and the failure has to be quickly recovered to minimize the impact. A unified home networking standard based on existing media in home has been developed to meet the increasing demand for bandwidth, reliability and availability. However, the fault tolerant protocol adopted by the home networking standard is based on an advanced selective ARQ (Automatic Retransmission Request) protocol which may take hundreds of millisecond to establish a backup channel. Alternatively, a hot standby backup channel has to be used to achieve quick switch without data loss at the expense of increased power consumption by the hot standby channel. The present invention discloses a quick-switch modem that can quickly switch from a primary channel to a backup channel upon detection of transmission failure. The quick-switch modem contains an additional interface between the modems for the primary channel and the secondary channel. In order to achieve quick failure detection and data re-route, the quick-switch modem relies on lower layers of the network link to facilitate failure detection and data re-route. Consequently, the switching time is substantially reduced without the need of hot standby. Alternatively, the quick-switch modem can be configured for load sharing to enhance overall available bandwidth.