Abstract: Downstream synchronous multichannel (DSSM) communications are provided among a plurality of carriers, each being a completely DOCSIS™ 2.0-compliant downstream. The synchronous multichannels support communications with both DSSM-capable communications nodes and non-DSSM-capable communications nodes (e.g., legacy cable modems). Non-DSSM packets are transmitted on a single channel. DSSM packets are split into multiple pieces, which are transmitted simultaneously on all available channels. Since the physical delay variation (e.g., group delay change) across the adjacent carriers is small (on the order of a symbol time), the multiple pieces arrive at the receiving communications nodes at nearly the same time and can be reassembled with minimal buffering and no packet ordering problems. To avoid causing trouble for the non-DSSM-capable communications nodes, the packet pieces are encapsulated with a header that causes the non-DSSM-capable communications nodes to silently discard them.

Abstract: A system, method and computer program product is provided for mitigating the effects of burst noise on packets transmitted in a communications system. A transmitting device applies an outer code, which may include, for example, a block code, an exclusive OR (XOR) code, or a repetition code, to one or more packets prior to adaptation of the packets for transmission over the physical (PHY) layer of the communications system, wherein the PHY layer adaptation may include FEC encoding of individual packets. The outer coded packets are then separately transmitted over a channel of the communications system. A receiving device receives the outer coded packets, performs PHY level demodulation and optional FEC decoding of the packets, and then applies outer code decoding to the outer coded packets in order to restore packets that were erased during transmission due to burst noise or other impairments on the channel.