1. A multipoint-to-point, orthogonal frequency division multiplexed (OFDM) communication system comprising:
a plurality of remote units;
a host unit that includes a demodulator;
wherein each of the remote units transmits an upstream OFDM signal using a multiple access scheme to the host unit demodulator using at least one of a plurality of orthogonal tones within an OFDM waveform;
wherein the host unit receives the upstream OFDM signals from a plurality of the remote units, the tones of the upstream signals being substantially orthogonal when received at the host unit;
wherein portions of upstream OFDM signals from at least two of the remote units arrive at the host unit at the same time;
wherein the host unit demodulator demodulates said portions; and
wherein each remote unit times its upstream signal transmission so that when multiple upstream signals arrive at the host unit, multiframes of the multiple upstream signals are aligned.
2. The OFDM communication system of claim 1 wherein the system is used in a hybrid fiber coax network.
3. The OFDM communication system of claim 1 wherein the system is used in a wireless network.
4. The OFDM communication system of claim 1 wherein at least one remote unit receives a timing adjustment command from the host unit to assist in aligning the multiframes of the upstream signals at the host unit.
5. The OFDM communication system of claim 4 wherein the timing adjustment command is transmitted from the host unit to the at least one remote unit via a control channel.
6. The OFDM communication system of claim 4 wherein the host unit repeatedly sends timing adjustment commands to the remote unit to maintain multiframe alignment of the upstream signals at the host unit.
7. A system comprising:
a host unit including a multicarrier demodulator;
a plurality of remote units using a multiple access scheme to communicate at the same time with the host unit multicarrier demodulator using orthogonal frequency division multiplexing (OFDM);
wherein each of the plurality of remote units transmits to the host unit using a multiframe pattern, each multiframe of the multiframe pattern being at least a predetermined plurality of consecutive symbols in duration;
wherein the host unit determines a timing error for at least one of the remote units; and
wherein the host unit sends a timing adjustment signal to the at least one remote unit so that multiframes received at the host unit from the plurality of remote units are aligned at the host unit.
8. The OFDM communication system of claim 7 wherein the system is used in a hybrid fiber coax network.
9. The OFDM communication system of claim 7 wherein the system is used in a wireless network.
10. The OFDM communication system of claim 7 wherein the at least one remote unit makes an adjustment to the timing of its upstream signal transmission based on the timing adjustment signal from the host unit.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A fault tolerant data processing architecture comprising:
a monolithic network of cells having array cells and spare cells interconnected in such a manner that a plurality of spare cells can directly replace functions of any given array cell of the network should that given array cell prove defective without an overhead of a plurality of dedicated replacement cells for each array cell; and
means for self-testing,
wherein said means for self testing further comprise means for array cells that test valid to vote to assassinate a defective neighbor cell by disconnecting a power supply of the defective neighbor cell.
2. A method for directly replacing defective array cells in a fault tolerant architecture, comprising steps of:
testing each array cell;
selecting a respective spare cell for each defective array cell; and
replacing the functions of the defective array cell with the respective spare cell,
wherein the step of testing each array cell comprises mapping a density of defective array cells surrounding each array cell.
3. The method as claimed in claim 2 wherein functions of defective cells are replaced in an order starting with a defective cell having a highest surrounding defect density and proceeding toward a defective cell having a lowest surrounding defect density.
4. The method as claimed in claim 2 wherein functions of defective cells are replaced in an order starting with a defective cell having a lowest number of unassigned spare cells and proceeding toward a defective cell having a highest number of unassigned spare cells.
5. A fault tolerant data processing architecture comprising:
a monolithic network of array cells and spare cells fabricated on a substrate that can be organized into a fault-free array of cells;
means for directly addressing each cell of the fault-free array of cells; and
means for each cell of the fault-free array of cells to send and receive data via a global data bus,
wherein each cell of the array of cells further comprises a plurality of memory bits addressable by word lines and bit lines, each of the memory bits comprising at least one spare bit-lines for tolerating a defective bit without requiring replacing the cell by a spare cell.
6. The architecture as claimed in claim 5 further comprising functions selected from the group consisting of BIOS (basic input output system) chips, video accelerators and inputoutput controllers fabricated on the substrate.
7. A fault tolerant data processing architecture comprising:
a monolithic network of array cells and spare cells fabricated on a substrate that can be organized into a fault-free array of cells;
means for directly addressing each cell of the fault-free array of cells; and
means for each cell of the fault-free array of cells to send and receive data via a global data bus,
wherein each cell of the array of cells further comprises a plurality of memory bits addressable by word lines and bit lines, each of the memory bits comprising at least one spare word-line for tolerating a defective bit without requiring replacing the cell by a spare cell.
8. A fault tolerant monolithic data processing architecture comprising:
a network of cells containing memory and processors that can be organized into a regular fault-free array of cells,
wherein the array of cells provides a parallel processing array, and
wherein the cells further comprise:
registers and local cache memory; and
means for using a register andor a local cache memory of an array cell as a cache memory of a processor of another array cell.
9. A fault tolerant data processing architecture comprising:
a network of cells containing memory and processors that can be organized into a fault-free array;
means for communication between neighboring cells; and
means for input and output to a global data bus,
wherein means for communication between neighboring cells comprises memory means placed between the neighboring cells and shared by the neighboring cells.
10. The architecture as claimed in claim 9 wherein means for communication between neighboring cells further comprises alignment insensitive contacts.
11. A fault tolerant data processing architecture comprising:
a network of cells containing memory and processors that can be organized into a fault-free array;
means for communication between neighboring cells;
means for input and output to a global data bus; and
means for a spare cell replacing a defective cell to copy the defective cell’s memory whereby enabling dynamic recovery from a post-manufacturing defect is enabled.
12. A fault tolerant data processing architecture comprising a network of cells containing memory, processors and a direct output element that can be organized into a fault-free array, wherein the memory and processors are capable of extracting output data for the direct output from a compressed data stream.
13. A fault tolerant data processing architecture comprising:
a redundant monolithic network of cells that can be organized into a regular fault-free array of cells,
wherein each cell has input and output means to a global data bus; means for input and output communication with neighboring cells in a plurality of dimensions; sufficient memory and processing power to decompress a data stream and to emulate at least one instruction from a microprocessor instruction set; full color direct output means; full color, capacitance touchproximity direct input means; and means to join a regional data bus.