CONTENTION-BASED ACCESS TO TONES IN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM) WAVEFORM
A bi-directional communication system is provided. The system includes a multipoint-to-point host unit and a plurality of remote units communicatively coupled to the multipoint-to-point host unit through an orthogonal frequency division multiplexing waveform. A first remote unit of the plurality of remote units is configured to transmit upstream information to the multipoint-to-point host unit using one or more tones within the orthogonal frequency division multiplexing waveform. The first remote unit of the plurality of remote units is configured to detect a potential collision on one or more tones transmitted from the first remote unit and signals transmitted on one or more of the same tones within the orthogonal frequency division multiplexing waveform by another remote unit of the plurality of remote units.
1 . A remote unit for a multi-point to point communication system, the remote unit comprising:
a multi-carrier transceiver coupled to a multipoint-to-point host unit, wherein the transceiver is configured to transmit upstream information to the multipoint-to-point host unit using one or more tones within an orthogonal frequency division multiplexing waveform;
a modem coupled to the multi-carrier transceiver, the modem configured to process the upstream information for transmission onto the one or more tones based on an inverse Fourier transform algorithm; and
a logic circuit coupled to the modem, the logic circuit configured to detect a potential collision on the one or more tones between signals transmitted by the multi-carrier transceiver and signals from another multi-carrier transceiver.
2 . The remote unit of claim 1 , wherein when the logic circuit detects the potential collision, the logic circuit directs the modem to re-transmit the one or more tones via the multi-carrier transceiver.
3 . The remote unit of claim 1 , wherein when the logic circuit detects the potential collision, the logic circuit is configured to direct the modem to transmit the one or more tones based on a back-off procedure.
4 . The remote unit of claim 1 , wherein the logic circuit is configured to detect the potential collision based on a signal from the multipoint-to-point host unit.
5 . The remote unit of claim 1 , the multi-carrier transceiver is coupled to the multipoint-to-point host unit by a distribution network coupled between the multipoint-to-point host unit and a plurality of remote units.
6 . The remote unit of claim 5 , wherein the distribution network comprises one of a wireless system and a hybrid fiber/coax network.
7 . A host unit for a multi-point to point communication system, the host unit comprising:
a multi-carrier transceiver communicatively coupled to a plurality of remote units through an orthogonal frequency division multiplexing waveform;
a modem that decodes upstream information from the orthogonal frequency division multiplexing waveform based on a Fourier transform algorithm; and
a logic circuit configured to direct the modem to transmit a message on at least one tone of the orthogonal frequency division multiplexing waveform based on whether the modem successfully receives the upstream information.
8 . The host unit of claim 7 , wherein the multi-carrier transceiver is communicatively coupled to the plurality of remote units by a distribution network coupled between the multipoint-to-point host unit and the plurality of remote units.
9 . The host unit of claim 8 , wherein the distribution network comprises one of a wireless system and a hybrid fiber/coax network.
10 . A bi-directional communication system, the system comprising:
a multipoint-to-point host unit;
a plurality of remote units communicatively coupled to the multipoint-to-point host unit through an orthogonal frequency division multiplexing waveform;
wherein a first remote unit of the plurality of remote units is configured to transmit upstream information to the multipoint-to-point host unit using one or more tones within the orthogonal frequency division multiplexing waveform;
wherein the first remote unit of the plurality of remote units is configured to detect a potential collision on one or more tones transmitted from the first remote unit and signals transmitted on one or more of the same tones within the orthogonal frequency division multiplexing waveform by another remote unit of the plurality of remote units.
11 . The system of claim 10 , wherein when the first remote unit detects the potential collision, the first remote unit re-transmits the upstream information to the multipoint-to-point host unit.
12 . The system of claim 10 , wherein when the first remote unit detects the potential collision, the first remote unit is configured to transmit the upstream information based on a back-off procedure.
13 . The system of claim 10 , wherein the first remote unit is configured to detect the potential collision based on a signal from the multipoint-to-point host unit.
14 . The system of claim 10 , the first remote unit coupled to the multipoint-to-point host unit by a distribution network coupled between the multipoint-to-point host unit and a plurality of remote units.
15 . The system of claim 14 , wherein the distribution network comprises one of a wireless system and a hybrid fiber/coax network.