Transport of gigabit ATM cell streams over lower order SDH backbone

A technique is presented to carry asynchronous transfer mode (ATM) cell streams over a lower speed synchronous transmission network. Although focus is on transport of gigabit cell streams over a lower order synchronous digital hierarchy (SDH) network, the proposed functionality is in fact directly applicable to any ATM stream over any lower speed synchronous network. The approach is a single ATM virtual path (VP) connection supported by multipath transmission. Delay equalisation is performed through a set of first-in first-out (FIFO) queues at the receiver side, which get mutually synchronised by the initial retrieval action of their common server. After start up, all FIFOs will exhibit different filling levels, compensating the delay differences along the paths. Once operational, no further transmission overhead is imposed. The proposed actions take place in the uppermost part of the physical layer