Method and apparatus for coordinating multi-point to-point communications in a multi-tone data transmission system

In a bi-directional data transmission system that facilitates communications between a plurality of remote units and a central unit using a frame based discrete multi-carrier transmission scheme that has a multiplicity of discrete sub-channels provided for facilitating upstream communications between the plurality of remote units and the central unit, a method of dynamically checking sub-carrier transmission quality from the remote units to the central unit to facilitate the allocation of bandwidth to the remote units by the central unit, the method comprising the steps of:

• (a) periodically providing synchronized quiet times on the plurality of discrete sub-channels provided for facilitating upstream communications, wherein remote units that are not requested to train or retrain during a particular training time are quiet during that particular training time;
• (b) transmitting training signals from a first one of the remote units over the multiplicity of sub-channels provided for facilitating upstream communications during a selected synchronized quiet time;
• (c) monitoring the training signals transmitted during the selected training time at the central unit and determining a first set of channel characteristics indicative of the capacities of the multiplicity of sub-channels provided for facilitating upstream communications;
• (d) saving the first set of channel characteristics within a matrix of channel characteristics, wherein said matrix contains information indicative of the channel capacities of the multiplicity of discrete sub-channels between all the remote units and the central unit, whereby the central unit may use the first set of channel characteristics when determining which sub-channels to allocate to the selected first remote unit for upstream communications;
• and
• (e) adjusting the set of sub-channels allocated to the selected first remote unit based upon a set of information derived from the plurality of training signals transmitted to the central unit.

In a bi-directional data transmission system that facilitates communications between a plurality of remote units and a central unit using a frame based discrete multi-carrier transmission scheme that has a multiplicity of discrete sub-channels provided for facilitating upstream communications between the plurality of remote units and the central unit, a method of dynamically checking sub-carrier transmission quality from the remote units to the central unit to facilitate the allocation of bandwidth to the remote units by the central unit, the method comprising the steps of:

• (a) periodically providing synchronized quiet times on the plurality of discrete sub-channels provided for facilitating upstream communications, wherein remote units that are not requested to train or retrain during a particular training time are quiet during that particular training time;
• (b) transmitting training signals from a first one of the remote units over the multiplicity of sub-channels provided for facilitating upstream communications during a selected synchronized quiet time;
• (c) monitoring the training signals transmitted during the selected training time at the central unit and determining a first set of channel characteristics indicative of the capacities of the multiplicity of sub-channels provided for facilitating upstream communications, whereby the central unit may use the first set of channel characteristics when determining which sub-channels to allocate to the selected first remote unit for upstream communications;
• and
• (d) repeating the transmitting and monitoring steps for a plurality of different remote units in order to determine channel characteristics for each of the plurality of different remote units to facilitate the dynamic allocation of bandwidth to various remote units, wherein different remote units transmit their respective training signals during different quiet times.

In a bi-directional data transmission system that facilitates communications between a plurality of remote units and a central unit using a frame based discrete multi-carrier transmission scheme that has a multiplicity of discrete sub-channels provided for facilitating upstream communications between the plurality of remote units and the central unit, a method of dynamically checking sub-carrier transmission quality from the remote units to the central unit to facilitate the allocation of bandwidth to the remote units by the central unit, the method comprising the steps of:

• (a) periodically providing synchronized quiet times on the plurality of discrete sub-channels provided for facilitating upstream communications, wherein remote units that are not requested to train or retrain during a particular training time are quiet during that particular training time;
• (b) transmitting training signals from a first one of the remote units over the multiplicity of sub-channels provided for facilitating upstream communications during a selected synchronized quiet time;
• (c) monitoring the training signals transmitted during the selected training time at the central unit and determining a first set of channel characteristics indicative of the capacities of the multiplicity of sub-channels provided for facilitating upstream communications, whereby the central unit may use the first set of channel characteristics when determining which sub-channels to allocate to the selected first remote unit for upstream communications;
• and
• (d) sending a retraining signal to the selected first remote unit, wherein the selected first remote unit only transmits its training signals in response to the reception of a retraining signal.

In a bi-directional data transmission system that facilitates communications between a plurality of remote units and a central unit using a frame based discrete multi-carrier transmission scheme that has a multiplicity of discrete sub-channels provided for facilitating upstream communications between the plurality of remote units and the central unit, a method of informing the central unit of the transmission requirements of a remote unit, the method comprising the steps of:

• periodically providing synchronized quiet times on the plurality of discrete sub-channels provided for facilitating upstream communications, wherein remote units that are not authorized to transmit data request information during a particular quiet time are quiet during that particular quiet time;
• transmitting a data transmission request signal from a selected first remote to the central unit at a time other than during a quiet time interval;
• transmitting an authorization signal to the selected first remote unit allocating a first quiet time to the selected first remote unit;
• transmitting data request information from the selected first remote to the central unit over a plurality of the discrete sub-channels during the first quiet time;
• and
• allocating at least one sub-channel to the selected first remote unit in response to the data request information for facilitating upstream communications between the first remote unit and the central unit.

In a bi-directional data transmission system that facilitates communications between a plurality of remote units and a central unit using a frame based discrete multi-carrier transmission scheme that has a multiplicity of discrete sub-channels provided for facilitating upstream communications between the plurality of remote units and the central unit, a method of dynamically checking sub-carrier transmission quality from the remote units to the central unit to facilitate the allocation of bandwidth to the remote units by the central unit, the method comprising the steps of:

• (a) periodically providing synchronized quiet times on the plurality of discrete sub-channels provided for facilitating upstream communications, wherein remote units that are not requested to train or retrain during a particular training time are quiet during that particular training time;
• (b) transmitting training signals from a first one of the remote units over the multiplicity of sub-channels provided for facilitating upstream communications during a selected synchronized quiet time;
• (c) monitoring the training signals transmitted during the selected training time at the central unit and determining a first set of channel characteristics indicative of the capacities of the multiplicity of sub-channels provided for facilitating upstream communications;
• (d) saving the first set of channel characteristics within a matrix of channel characteristics, wherein said matrix contains information indicative of the channel capacities of the multiplicity of discrete sub-channels between all the remote units and the central unit, whereby the central unit may use the first set of channel characteristics when determining which sub-channels to allocate to the selected first remote unit for upstream communications;
• and
• (e) repeating the transmitting and monitoring steps for a plurality of different remote units in order to determine channel characteristics for each of the plurality of different remote units to facilitate the dynamic allocation of bandwidth to various remote units, wherein different remote units transmit their respective training signals during different quiet times.

In a bi-directional data transmission system that facilitates communications between a plurality of remote units and a central unit using a frame based discrete multi-carrier transmission scheme that has a multiplicity of discrete sub-channels provided for facilitating upstream communications between the plurality of remote units and the central unit, a method of dynamically checking sub-carrier transmission quality from the remote units to the central unit to facilitate the allocation of bandwidth to the remote units by the central unit, the method comprising the steps of:

• (a) periodically providing synchronized quiet times on the plurality of discrete sub-channels provided for facilitating upstream communications, wherein remote units that are not requested to train or retrain during a particular training time are quiet during that particular training time;
• (b) transmitting training signals from a first one of the remote units over the multiplicity of sub-channels provided for facilitating upstream communications during a selected synchronized quiet time;
• (c) monitoring the training signals transmitted during the selected training time at the central unit and determining a first set of channel characteristics indicative of the capacities of the multiplicity of sub-channels provided for facilitating upstream communications;
• (d) saving the first set of channel characteristics within a matrix of channel characteristics, wherein said matrix contains information indicative of the channel capacities of the multiplicity of discrete sub-channels between all the remote units and the central unit, whereby the central unit may use the first set of channel characteristics when determining which sub-channels to allocate to the selected first remote unit for upstream communications;
• (e) adjusting the set of sub-channels allocated to the selected first remote unit based upon a set of information derived from the plurality of training signals transmitted to the central unit;
• and
• (f) sending a retraining signal to the selected first remote unit, wherein the selected first remote unit only transmits its training signals in response to the reception of a retraining signal.

In a bi-directional data transmission system that facilitates communications between a plurality of remote units and a central unit using a frame based discrete multi-carrier transmission scheme that has a multiplicity of discrete sub-channels provided for facilitating upstream communications between the plurality of remote units and the central unit, a method of dynamically checking sub-carrier transmission quality from the remote units to the central unit to facilitate the allocation of bandwidth to the remote units by the central unit, the method comprising the steps of:

• (a) periodically providing synchronized quiet times on the plurality of discrete sub-channels provided for facilitating upstream communications, wherein remote units that are not requested to train or retrain during a particular training time are quiet during that particular training time;
• (b) transmitting training signals from a first one of the remote units over the multiplicity of sub-channels provided for facilitating upstream communications during a selected synchronized quiet time;
• (c) monitoring the training signals transmitted during the selected training time at the central unit and determining a first set of channel characteristics indicative of the capacities of the multiplicity of sub-channels provided for facilitating upstream communications;
• (d) saving the first set of channel characteristics within a matrix of channel characteristics, wherein said matrix contains information indicative of the channel capacities of the multiplicity of discrete sub-channels between all the remote units and the central unit, whereby the central unit may use the first set of channel characteristics when determining which sub-channels to allocate to the selected first remote unit for upstream communications;
• and
• (e) sending a retraining signal to the selected first remote unit, wherein the selected first remote unit only transmits its training signals in response to the reception of a retraining signal.

In a bi-directional data transmission system that facilitates communications between a plurality of remote units and a central unit using a frame based discrete multi-carrier transmission scheme that has a multiplicity of discrete sub-channels provided for facilitating upstream communications between the plurality of remote units and the central unit, a method of dynamically checking sub-carrier transmission quality from the remote units to the central unit to facilitate the allocation of bandwidth to the remote units by the central unit, the method comprising the steps of:

• (a) periodically providing synchronized quiet times on the plurality of discrete sub-channels provided for facilitating upstream communications, wherein remote units that are not requested to train or retrain during a particular training time are quiet during that particular training time;
• (b) transmitting training signals from a first one of the remote units over the multiplicity of sub-channels provided for facilitating upstream communications during a selected synchronized quiet time;
• (c) monitoring the training signals transmitted during the selected training time at the central unit and determining a first set of channel characteristics indicative of the capacities of the multiplicity of sub-channels provided for facilitating upstream communications;
• (d) saving the first set of channel characteristics within a matrix of channel characteristics, wherein said matrix contains information indicative of the channel capacities of the multiplicity of discrete sub-channels between all the remote units and the central unit, whereby the central unit may use the first set of channel characteristics when determining which sub-channels to allocate to the selected first remote unit for upstream communications;
• (e) adjusting the set of sub-channels allocated to the selected first remote unit based upon a set of information derived from the plurality of training signals transmitted to the central unit;
• and
• (f) sending a retraining signal to the selected first remote unit, wherein the selected first remote unit only transmits its training signals in response to the reception of a retraining signal.

In a bi-directional data transmission system that facilitates communications between a plurality of remote units and a central unit using a frame based discrete multi-carrier transmission scheme that has a multiplicity of discrete sub-channels provided for facilitating upstream communications between the plurality of remote units and the central unit, a method of dynamically checking sub-carrier transmission quality from the remote units to the central unit to facilitate the allocation of bandwidth to the remote units by the central unit, the method comprising the steps of:

• (a) periodically providing synchronized quiet times on the plurality of discrete sub-channels provided for facilitating upstream communications, wherein remote units that are not requested to train or retrain during a particular training time are quiet during that particular training time;
• (b) transmitting training signals from a first one of the remote units over the multiplicity of sub-channels provided for facilitating upstream communications during a selected synchronized quiet time;
• (c) monitoring the training signals transmitted during the selected training time at the central unit and determining a first set of channel characteristics indicative of the capacities of the multiplicity of sub-channels provided for facilitating upstream communications;
• (d) saving the first set of channel characteristics within a matrix of channel characteristics, wherein said matrix contains information indicative of the channel capacities of the multiplicity of discrete sub-channels between all the remote units and the central unit, whereby the central unit may use the first set of channel characteristics when determining which sub-channels to allocate to the selected first remote unit for upstream communications;
• and
• (e) sending a retraining signal to the selected first remote unit, wherein the selected first remote unit only transmits its training signals in response to the reception of a retraining signal.

In a bi-directional data transmission system that facilitates communications between a plurality of remote units and a central unit using a frame based discrete multi-carrier transmission scheme that has a multiplicity of discrete sub-channels provided for facilitating upstream communications between the plurality of remote units and the central unit, a method of dynamically checking sub-carrier transmission quality from the remote units to the central unit to facilitate the allocation of bandwidth to the remote units by the central unit, the method comprising the steps of:

• (a) periodically providing synchronized quiet times on the plurality of discrete sub-channels provided for facilitating upstream communications, wherein remote units that are not requested to train or retrain during a particular training time are quiet during that particular training time;
• (b) transmitting training signals from a first one of the remote units over the multiplicity of sub-channels provided for facilitating upstream communications during a selected synchronized quiet time;
• (c) monitoring the training signals transmitted during the selected training time at the central unit and determining a first set of channel characteristics indicative of the capacities of the multiplicity of sub-channels provided for facilitating upstream communications;
• (d) saving the first set of channel characteristics within a matrix of channel characteristics, wherein said matrix contains information indicative of the channel capacities of the multiplicity of discrete sub-channels between all the remote units and the central unit, whereby the central unit may use the first set of channel characteristics when determining which sub-channels to allocate to the selected first remote unit for upstream communications;
• (e) adjusting the set of sub-channels allocated to the selected first remote unit based upon a set of information derived from the plurality of training signals transmitted to the central unit;
• and
• (f) sending a retraining signal to the selected first remote unit, wherein the selected first remote unit only transmits its training signals in response to the reception of a retraining signal.

In a bi-directional data transmission system that facilitates communications between a plurality of remote units and a central unit using a frame based discrete multi-carrier transmission scheme that has a multiplicity of discrete sub-channels provided for facilitating upstream communications between the plurality of remote units and the central unit, a method of dynamically checking sub-carrier transmission quality from the remote units to the central unit to facilitate the allocation of bandwidth to the remote units by the central unit, the method comprising the steps of:

• (a) periodically providing synchronized quiet times on the plurality of discrete sub-channels provided for facilitating upstream communications, wherein remote units that are not requested to train or retrain during a particular training time are quiet during that particular training time;
• (b) transmitting training signals from a first one of the remote units over the multiplicity of sub-channels provided for facilitating upstream communications during a selected synchronized quiet time;
• (c) monitoring the training signals transmitted during the selected training time at the central unit and determining a first set of channel characteristics indicative of the capacities of the multiplicity of sub-channels provided for facilitating upstream communications;
• (d) saving the first set of channel characteristics within a matrix of channel characteristics, wherein said matrix contains information indicative of the channel capacities of the multiplicity of discrete sub-channels between all the remote units and the central unit, whereby the central unit may use the first set of channel characteristics when determining which sub-channels to allocate to the selected first remote unit for upstream communications;
• (e) adjusting the set of sub-channels allocated to the selected first remote unit based upon a set of information derived from the plurality of training signals transmitted to the central unit;
• (f) repeating the transmitting and monitoring steps for a plurality of different remote units in order to determine channel characteristics for each of the plurality of different remote units to facilitate the dynamic allocation of bandwidth to various remote units, wherein different remote units transmit their respective training signals during different quiet times;
• and
• (g) sending a retraining signal to the selected first remote unit, wherein the selected first remote unit only transmits its training signals in response to the reception of a retraining signal.