Overhead handling method and system for high order data streams

The method according to any one of the preceding claims, wherein the step. (a) comprises defining a basic data stream of the component data stream wherein the basic data stream with its payload portion and its overhead portion is a building block of the component data stream.

The method according to any one of the preceding claims, further comprising providing a set of N sample buffers SB and a set of N insert buffers IB respectively corresponding to the N component data streams.

The method according to any one of the preceding claims, wherein the step (d) of processing each of said overhead bytes in the COHPU is performed at the bit rate of said component data stream, and comprises:

• creating and keeping a complete ID information including the number of component data stream to which each particular OH byte belongs,
• successively forwarding each particular received OH byte to an operator block corresponding to the type of said particular overhead byte and the kind of processing required for the byte, said operator blocks forming part of said common processing unit,
• obtaining results of the processing of each particular OH byte in the form of at least one instruction selected from a list comprising alarms, operations with the particular overhead byte in the outgoing high order data stream and operations with other bytes in the outgoing high order data stream.

The method according to any one of the preceding claims, wherein the step (e) of modifying the component data streams comprises the following sub-steps:

• based on results of the processing, transmitting from the COHPU at least one instruction with respect to each of said overhead bytes, wherein the transmitting being provided to N insert buffers respectively assigned to the N component data streams so that said instructions arrive in turn to the respective insert buffers according to said ID information;
• and
• executing said instructions at said N respective insert buffers, for the respective component data streams of the incoming high order data stream, thereby obtaining N component data streams of the outgoing high order data stream.

The method according to any one of the preceding claims, wherein the step (a) is performed as composing the incoming high order data stream STM-256 as 16 component data streams STM-16 transmitted in parallel, where each of the component data streams consists either of 48 basic data streams STS-1 for SONET hierarchy or 48 VC-3 for SDH hierarchy.