System and method for performing rate adaptation and multiplexing of constant bit rate (CBR) client data for transmission over a metro transport network (MTN)

A method for performing rate adaptation of two or more streams of client data for transmission over a Metro Transport Network (MTN), the method comprising:

• receiving two or more streams of 64B/66B-encoded blocks of constant bit rate (CBR) client data at a source node;
• defining a plurality of generic mapping procedure (GMP) thread frames, wherein respective GMP thread frames include a variable number of 64B/66B-encoded blocks of CBR client data, a variable number of pad blocks and GMP overhead for the respective stream of 64B/66B-encoded blocks of CBR client data;
• defining a plurality of pseudo-Ethernet packets, wherein respective pseudo-Ethernet packets include a plurality of data payload blocks divided into a plurality of interleaved threads and a plurality of interleaved GMP overhead data payload blocks;
• mapping the plurality of GMP thread frames into consecutive pseudo-Ethernet packets of the plurality of pseudo-Ethernet packets, by mapping the variable number of 64B/66B-encoded blocks of CBR client data and the variable number of pad blocks into respective ones of the plurality of consecutive pseudo-Ethernet packets and mapping the GMP overhead into the plurality of interleaved GMP overhead data payload blocks;
• assembling a stream of GMP multiplexing frames comprising the consecutive pseudo-Ethernet packets;
• inserting a fixed number of idle blocks between the consecutive pseudo-Ethernet packets of the stream of GMP multiplexing frames;
• inserting an MTN path overhead (POH) frame that is aligned to the stream of GMP multiplexing frames to generate a stream of GMP multiplexing rate adapted frames;
• transmitting the stream of GMP multiplexing rate adapted frames, including the fixed number of idle blocks, over the MTN;
• receiving the stream of GMP multiplexing rate adapted frames and the fixed number of idle blocks at a first intermediate node of the MTN;
• performing idle mapping procedure (IMP) rate adaptation of the stream of rate adapted GMP multiplexing rate adapted frames received at the first intermediate node to modify the fixed number of idle blocks;
• transmitting the stream of GMP multiplexing rate adapted frames and the modified fixed number of idle blocks from the intermediate node to a sink node of the MTN;
• receiving the stream of rate adapted GMP multiplexing rate adapted frames and the modified fixed number of idle blocks at the sink node;
• determining, for respective interleaved threads, a corresponding client data stream rate from the GMP overhead and a difference between the fixed number of idle blocks inserted into the stream GMP multiplexing frames by the source node and the modified number of idle blocks received at the sink node;
• and
• extracting the two or more streams of 64B/66B-encoded blocks of CBR client data from the stream of GMP multiplexing rate adapted frames using the corresponding client data stream rate for the respective interleaved thread.

A source node for transmitting a client data stream over a Metro Transport Network (MTN), the source node comprising circuitry to:

• receive two or more streams of 64B/66B-encoded blocks of constant bit rate (CBR) client data;
• define a plurality of generic mapping procedure (GMP) thread frames, wherein respective GMP thread frames include a variable number of the 64B/66B-encoded blocks of CBR client data, a variable number of pad blocks and GMP overhead for the respective stream of 64B/66B encoded blocks of CBR client data;
• define a plurality of pseudo-Ethernet packets, wherein respective pseudo-Ethernet packets include a plurality of data payload blocks divided into a plurality of interleaved threads and a plurality of interleaved generic mapping procedure GMP overhead data payload blocks;
• map the plurality of GMP thread frames into consecutive pseudo-Ethernet packets of the plurality of pseudo-Ethernet packets, by mapping the variable number of 64B/66B-encoded blocks of CBR client data and the variable number of pad blocks into respective ones of the plurality of consecutive pseudo-Ethernet packets and mapping the GMP overhead into the plurality of interleaved GMP overhead data payload blocks;
• assemble a stream of GMP multiplexing frames comprising the consecutive pseudo-Ethernet packets;
• insert a fixed number of idle blocks between the consecutive pseudo-Ethernet packets of the stream of GMP multiplexing frames;
• and
• insert an MTN path overhead (POH) frame that is aligned to the stream of GMP multiplexing frames to generate a stream of GMP multiplexing rate adapted frames.