Patent ID: 7787448

Claim:
A method for transparent transport of optical channel transmission unit (OTU) signals via an optical transport network (OTN), the method comprising: reserving an OTUj control overhead of OTUj signals entering an OTN network; converting said OTUj signals mapping into OTUk signals of the current OTN network for transmission, when said OTUk signals arriving at a boundary of the current OTN network, wherein said converting of said OTUj signals mapping into OTUk signals of the current OTN network for transmission includes: extending an ODUj signal of OTUj signals, extending the reserved OTUj overhead as a part of the ODUj signal, asynchronously mapping the extended ODUj signal to optical channel data branch unit signals, multiplexing the multiple optical channel data branch unit signals to a payload area, generating an OTUk control overhead and an OTUk forward error correction (FEC) code, and assembling said OTUk signals; demapping said OTUk signals and converting them to the OTUj signals; continuously using said reserved OTUj control overhead as the OTUj control overhead for OTUj signals; and sending out OTUj signals from the OTN network, wherein j and k represent a rate rank of said OTN signals, respectively, and the value of j is smaller than the value of k.