Method and apparatus for LDPC transmission over a channel bonded link
View Patent ↗A particular overall architecture for transmission over a bonded channel system consisting of two interconnected MoCA (Multimedia over Coax Alliance) 2.0 SoCs (“Systems on a Chip) and a method and apparatus for the case of a “bonded” channel network. With a bonded channel network, the data is divided into two segments, the first of which is transported over a primary channel and the second of which is transported over a secondary channel.
1. A method for bonding a first and second channels of a home network comprising:
a) determining that a transmitting node has an aggregated packet data unit (A-PDU) to be transmitted, the A-PDU comprised of M bytes;
b) if both the transmitting node and a receiving node are capable of operating with channel bonding, and the A-PDU is to have either a unicast profile in channel bonding or a VLPER (very low packet error rate) unicast profile in channel bonding, then calculating a number of symbols (Nsym) required to transmit the M bytes of the A-PDU by;
i) calculating an approximate maximum number of payload bits per OFDM symbol for each channel (MBAS,i) by multiplying a number of bits per Orthogonal Frequency Division Multiplexing (OFDM) symbol for the first channel (NBAS,i) with a quotient of the maximum LDPC codeword payload sizes from EVM reports for the first channel (kLDPCmax,1) divided by a sum of the maximum LDPC codeword payload sizes from EVM reports for the first channel (kLDPCmax,1) and a number of parity bits per LDPC codeword (Nparity);
ii) calculating a ratio of a payload that can be carried by a primary channel with respect to an extension channel with 16 bit precision (pi);
iii) if a product of the ratio pi times a sum of a number of bytes M in the A-PDU plus a number of bytes M OH in a bonded channel frame splitting overhead minus 18 is a multiple of 4, then calculating a number of bytes M 1 to be transmitted by the transmitting node in the primary channel as a product of the ratio pi times the sum of the number of bytes in the A-PDU M plus the number of bytes in the bonded channel frame splitting overhead M OH
iv) if the product of the ratio pi times the sum of the number of bytes M in the A-PDU plus the number of bytes M OH in the bonded channel frame splitting overhead minus 18 is not a multiple of 4, then calculating the number of bytes M 1 to be transmitted by the transmitting node in the primary channel by extending a primary channel fragment (minus the MoCA header of 18 bytes) to the nearest 4 byte boundary, but not exceeding M;
v) calculating a payload of a secondary channel M 2 as the sum of Mbytes plus the number of bytes M OH in the bonded channel frame splitting overhead minus the number of bytes M 1 to be transmitted by the transmitting node in the primary channel; and
vi) calculating the number of symbols required to transmit the M bytes of the A-PDU based on the number of bytes M 1 to be transmitted by the transmitting node in the primary channel and the number of bytes M 2 to be transmitted by the transmitting node in the secondary channel.
2. The method of claim 1 , wherein the step of iv) comprises calculating M 1 as a minimum of:
a) M; and
b) a difference of pi times a sum of the number of bytes M in the A-PDU plus the number of bytes M OH , in the bonded channel frame splitting overhead, that product plus four and modulo four of the difference of the product of the sum of number of bytes M in the A-PDU plus the number of bytes M OH , in the bonded channel frame splitting overhead and 18.