Abstract: One embodiment of the present invention is a method for transmitting information over an AC power line. A frequency channel for transmitting the information is selected and divided into a plurality of frequency orthogonal subchannels. Each of the frequency orthogonal subchannels is tested to determine a value of a transmission characteristic, which in turn is used to determine a transmission bit density for the frequency orthogonal subchannel. The information is divided into a plurality of data subblocks. Each data subblock corresponds to one of the frequency orthogonal subchannels, and the size of each data subblock is determined based on the corresponding transmission bit density. The data of each data subblock is modulated for transmission through the corresponding frequency orthogonal subchannel. Each data subblock is transmitted approximately concurrently through the corresponding frequency orthogonal subchannel.

Abstract: Briefly, in accordance with one embodiment of the invention, a method of encoding data signals for storage to tolerate failure of a storage unit of a storage medium includes the following. For N+2 storage units, N being a positive integer, each of the storage units being divided into N storage blocks, 2N blocks of priority signals are produced from (N)(N) blocks of data signals. The N(N+2) blocks of parity and data signals are allocated over the N+2 storage units of the storage medium so that the 2N blocks of parity signals are not exclusively stored in two of the N+2 storage units.