Patent ID: 6487223
Filing Date: 2002-11-26
Classification: H04J,H04Q

Abstract:
An SDH transmission apparatus which multiplexes transmission signals according to a multiplexing hierarchy, comprising:a mounting rack having a plurality of module slots and a backplane providing electrical interconnection among functional modules installed in the plurality of module slots; a cross-connect unit, installed in dedicated cross-connect unit slots on said mounting rack, which comprises high-order group ports and low-order group ports; at least one high-order group transmission unit, installed in dedicated high-order group slots on said mounting rack to handle high-order digital bitstreams to communicate with equipment outside the SDH transmission apparatus, which sends and receives multiplexed signals at a predetermined level of the multiplexing hierarchy to/from the high-order group ports of said cross-connect unit; and a plurality of low-order group transmission units, installed in dedicated low-order group slots on said mounting rack to handle low-order digital bitstreams to communicate with equipment outside the SDH transmission apparatus, which sends and receives the multiplexed signals at the predetermined level of the multiplexing hierarchy to/from the low-order group ports of said cross-connect unit wherein the predetermined level of the multiplexing hierarchy is fixed regardless of the bitrates of the high-order digital bitstreams or low-order digital bitstreams.