Abstract: A signaling protocol process is described for setting up and controlling end to end data link connections. An optimal data path can be selected and configured by a digital subscriber loop (DSL) user based on particular bandwidth requirements, data rate cost constraints, and/or data delay requirements. The data path can be set up to include one or more data routes, including through a regular digital public switching telephone network (PSTN), various kinds of wide area networks (WANs), and virtual permanent circuit links via digital cross-connects (DCS).

Abstract: A high speed software modem is described which uses a selectable, desirable portion of the total available bandwidth of a transmission channel. In a preferred embodiment, the invention is implemented in a personal computer connected to an upstream transceiver through a channel supporting an Asymmetric Digital Subscriber Loop (ADSL) standard. The achievable target data rate of the modem is based on the capabilities of an analog front end (AFE) used in the modem, and a host processor within such personal computer. In particular, the modem AFE contains subband filtering which causes an upstream transceiver to use only a selected number of available sub-channels for downstream data transmission. The data rate of the modem is increased by upgrading the AFE or the host processor in order to increase the number of processable transmitted downstream sub-channels.

Abstract: A process for optimizing the bit and energy configurations of data sub-channels in a multi-channel data transmission signal is disclosed. The inventive process is preferably embodied in an microcode routine executable by a high speed digital signal processor. The routine monitors, analyzes and stores sub-channel signal-to-noise characteristics, determines theoretical bit capacity loadings, evaluates power performance margins, and optimizes sub-channel configurations based on a series of iterative calculations intended to maximize the overall system power performance margin for any given target data rate. Alternatively, for a given power performance margin, the achieved data rate can be maximized. To achieve these results, a number of non-zero bit sub-channels (N.sub.CH) are remembered from iteration to iteration, which results in a more optimal loading of the sub-channels. A unique new approach is also disclosed for deciding which of the sub-channels should be disabled to have a zero bit loading.

Abstract: A circuit for optimizing the bit and energy configurations of data sub-channels in a multi-channel data transmission signal is disclosed. The circuit preferably includes a high speed memory coupled to a digital signal processor running an executable routine for analyzing sub-channel signal-to-noise characteristics, determining theoretical bit capacity loadings, evaluating power performance margins, and optimizing sub-channel configurations based on a series of iterative calculations intended to maximize the overall system power performance margin for any given target data rate. The circuit keeps track of the number of non-zero bit sub-channels (N.sub.CH) from iteration to iteration, which results in a more accurate loading of the sub-channels.

Abstract: A high speed modem is provided which uses a selectable, desirable portion of the total available bandwidth of a transmission channel. In a preferred embodiment, the invention is incorporated in a dedicated hardware circuit which is connected on one end to a data processor and on the other end to an upstream transceiver through a channel supporting an Asymmetric Digital Subscriber Loop (ADSL) standard. The achievable target data rate of the modem is based on the capabilities of an analog front end (AFE) used in the modem, and a signal processor within the dedicated hardware. In particular, the modem AFE contains subband filtering which causes an upstream transceiver to use only a selected number of available sub-channels for downstream data transmission. The data rate of the modem is increased by upgrading the AFE or the signal processor in order to increase the number of processable transmitted downstream sub-channels.

Abstract: A high speed modem is described that implements a scalable data rate ADSL link. The target data rate of the modem is scaled appropriately relative to a maximum available protocol rate by a factor M based on the signal processing capabilities available for performing DMT modulation and demodulation. An upstream transceiver is informed of the proposed scaling factor during a handshaking procedure, and thereafter the data rate of the channel is then scaled down by sending M copies of the same DMT symbol to the upstream transceiver, which effectively reduces the rate by such factor M. A self-executing calibration routine can be used for determining the appropriate scaling factor for such device, or alternatively, in some contexts a user can configure such scaling factor directly through a suitable interface.

Abstract: A circuit for optimizing and adapting the bit and energy configurations of data sub-channels in a multi-channel data transmission signal is disclosed. The circuit preferably includes a high speed memory coupled to a digital signal processor running an executable routine for analyzing sub-channel signal-to-noise characteristics, determining theoretical bit capacity loadings, evaluating power performance margins, and optimizing initial and adaptive sub-channel configurations based on a series of iterative calculations intended to maximize the overall system power performance margin for any given target data rate. The circuit keeps track of the number of non-zero bit sub-channels (N.sub.CH) from iteration to iteration, which results in a more accurate loading of the sub-channels.

Abstract: An ADSL transceiver includes a new circuit and various iterative initialization and fine tuning routines for optimizing the bit and energy configurations of data sub-channels in a multi-channel data transmission signal. The routines quickly converge to a target data rate by first estimating a power margin, and generating a bounded interval that includes the target rate. Thereafter, a binary iterative portion of the routine takes over and effectuates a final convergence to the target rate. A new mechanism for determining useful sub-channels is also disclosed. The resulting routines are extremely useful in that they maximize a data rate for a given power margin, and conversely, maximize a power margin for a given data rate. Two variants of a fine tuning process are also disclosed, and both can be used in combination to maximize system performance.

Abstract: An adaptive process for optimizing the bit and energy configurations of data sub-channels in a multi-channel data transmission signal is disclosed. The inventive process is preferably embodied in one or more microcode routines executable by a high speed digital signal processor. A first routine initializes the transmission system, while a second routine adaptively changes system parameters as necessary to accommodate channel performance changes, varying target bit rates, etc. Both of the routines monitor, analyze and store sub-channel signal-to-noise characteristics, determine theoretical bit capacity loading, evaluates power performance margin, and optimize sub-channel configurations based on a series of iterative calculations intended to maximize the overall system power performance margin for any given target data rate. Alternatively, for a given power performance margin, the achieved data rate can be maximized. To achieve these results, a number of non-zero bit sub-channels (N.sub.

Abstract: An applications program is provided for permitting a user of a host processing system to dynamically control a modem having forward compatible and expandable functionality. In a preferred embodiment, the applications program is designed to run on a personal computer running the Windows.RTM. shell, and the modem is compatible with ADSL promulgated standards. As part of such program, initialization and detection routines determine the capabilities of an ADSL modem, including whether the same has been upgraded to have enhanced data throughput. A calibration routine measures the computing power available to the host processor, and based on this information and other relevant parameters determines nominal setup parameters for the modem. These parameters are stored in a Device Parameter Table so that they can be accessed by various application programs that may make use of such modem.

Abstract: A high speed modem is provided which targets the use of a selectable, desirable portion of the total available bandwidth of a channel for achieving a data rate which nevertheless far exceeds that of conventional voice-band modems. In a preferred embodiment, the invention is implemented in an Asymmetric Digital Subscriber Loop (ADSL), and the nominal data rate is achieved using an analog front end (AFE) with subband filtering which causes an upstream transceiver to use only a selected number of available sub-channels for downstream data transmission and allows slower sampling rate for the AFE. The data rate of the modem is increased in a multiplicative fashion through modular expansion of a bank of AFEs to increase the number of transmitted downstream sub-channels.