SYSTEMS FOR CONTENTION-BASED BANDWIDTH REQUESTS IN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYSTEMS
Systems for contention-based bandwidth requests in orthogonal frequency division multiplexing (OFDM) systems are provided. In one embodiment, a bidirectional communication system comprises: a multipoint-to-point host; and a plurality of remotes communicatively coupled to the multipoint-to-point host through an OFDM waveform; wherein the multipoint-to-point host is configured to receive the OFDM waveform, the OFDM waveform comprising a plurality of tones transmitted by the plurality of remotes, wherein the plurality of tones are simultaneously received at the host from at least two of the plurality of remotes; wherein a first remote is configured to transmit a request for bandwidth to the host on a first tone of the plurality of tones, wherein access to the first tone is contention based; and wherein the multipoint-to-point host transmits information on at least one tone based on whether the host successfully receives the request for bandwidth from the first remote of the plurality of remotes.
1 . A bidirectional communication system, the system comprising:
a host unit to communicate with a plurality of remote units using orthogonal frequency division multiplexing, the plurality of remote units communicatively coupled to the host unit in a multipoint-to-point configuration;
the host unit receiving an orthogonal frequency division multiplexing waveform, the orthogonal frequency division multiplexing waveform comprising a plurality of tones transmitted by the plurality of remote units, wherein the plurality of tones are simultaneously received at the host unit from at least two of the plurality of remote units; and
wherein the host unit comprises a logic circuit configured to direct a modulator to transmit information on at least one tone of the orthogonal frequency division multiplexing waveform based on whether the host unit successfully receives a request for bandwidth from a first remote unit of the plurality of remote units via a contention based tone.
2 . A bidirectional communication system, the system comprising:
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;
wherein the multipoint-to-point host unit is configured to receive the orthogonal frequency division multiplexing waveform, the orthogonal frequency division multiplexing waveform comprising a plurality of tones transmitted by the plurality of remote units, wherein the plurality of tones are simultaneously received at the host unit from at least two of the plurality of remote units;
wherein a first remote unit of the plurality of remote units is configured to transmit a request for bandwidth to the host unit on a first tone of the plurality of tones, wherein access to the first tone is contention based; and
wherein the multipoint-to-point host unit transmits information on at least one tone of the orthogonal frequency division multiplexing waveform based at least in part on whether the host unit successfully receives the request for bandwidth from the first remote unit of the plurality of remote units.
3 . The system of claim 2 , wherein the first remote unit is further configured to retransmit the request for bandwidth in the event of a collision on the first tone.
4 . The system of claim 2 , wherein the first remote unit is further configured to retransmit the request for bandwidth using an exponential back-off procedure in the event of a collision on the first tone.
5 . The system of claim 2 , wherein the first remote unit is configured to detect a potential collision on the first tone between signals transmitted by the first remote unit and signals from another remote unit.
6 . The system of claim 2 , wherein the first remote unit is configured to detect a potential collision on the first tone based on whether the information is received from the multipoint-to-point host unit.