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US 2002/0176432 A1Published application
Hitless protection switching
AssigneeNortel Networks Limited
InventorsJohn Courtney, David M. Goodman, Mark Carson
Life of this patent
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AssigneeNortel Networks Limited
InventorsJohn Courtney, David M. Goodman, Mark Carson
Estimating the term…
The invention provides a method and apparatus for providing hitless protection switching in a synchronous transmission system. A switching apparatus is arranged to receive data signals on at least two transmission paths and to output data from a selected one of said transmission paths. The apparatus is arranged to align the respective received data signals so that a selector mechanism can select between corresponding elements of the received data signals. This arrangement allows hitless switching to be performed since there is no loss or repetition of signal elements when switching occurs. In a preferred embodiment, data in respect of each frame of each data signal is stored and the selector mechanism selects between paths on a frame-by-frame basis by comparing quality information carried by the data signals. This arrangement offers a very low end to end Bit Error Rate (BER) performance.
A switching apparatus arranged to receive data signals on at least two transmission paths and to output data from a selected one of said transmission paths, the apparatus including a selector mechanism for selecting between transmission paths, wherein the apparatus is arranged to align the respective data signals received on said transmission paths so that said selector mechanism is able to select between corresponding elements of said received data signals.
In a switching apparatus arranged to receive data signals on at least two transmission paths and to output data from a selected one of said transmission paths, a method of switching between transmission paths, the method comprising aligning the respective data signals received on said transmission paths;
In a synchronous transmission system comprising a first synchronous transmission apparatus arranged to transmit data signals across a network on at least two transmission paths;
Dependencies are inferred from the claim text.