Abstract: A method and system for determining a data communication frequency plan. Some exemplary embodiments include an iterative method used in a data communication system, comprising: selecting a target data rate and a target loop length (rate/reach target) from a plurality of rate/reach targets; defining a frequency plan that supports the selected rate/reach target; and aggregating the defined frequency plan into an overall frequency plan. The selecting, defining and aggregating are performed in each of multiple iterations within a cycle. At the end of an iteration the overall frequency plan permits transmission of data at the target data rate stored in the rate/reach target selected in the iteration.

Abstract: The present invention provides, in one embodiment, a method of simplifying filtering with respect to a band plan. The method includes selecting a reflection point relative to the band plan and designating subchannels as unusable within a filterable separation of the reflection point that would otherwise introduce an asymmetry within the filterable separation. The present invention also provides a filtering simplifier for use with a DSL system having a band plan. The filtering simplifier includes a reflection point selector configured to select a reflection point relative to the band plan. The filtering simplifier also includes a subchannel designator coupled to the reflection point selector and configured to designate subchannels as unusable within a filterable separation of the reflection point that would otherwise introduce an asymmetry within the filterable separation.

Abstract: A variety of methods of initializing a connection between a remote modem and a central unit in a communication system that utilizes a multi-carrier modulation scheme are described. In one aspect of the invention, a relatively long duration single frequency activation signal that ramps up and ramps down in intensity is utilized. In a preferred embodiment, the activation signal is transmitted on a sub-carrier that is outside a range of sub-channels used for data transmission in the multi-carrier modulation scheme. In a separate aspect of the invention, an initialization sequence that includes central synchronization signal, a remote synchronization signal, a central setup signal, a remote setup signal, a central setup complete signal a remote message and a central message. The central unit transmits a central setup complete signal when it has completed a central setup procedure.

Abstract: A superatmospheric combustion apparatus and a method of operating such an apparatus include providing a superatmospheric combustion device having a lean gas chamber, a combustor, a heat recovery section, and an exhaust, feeding lean gas to the lean gas chamber, providing a heat sink/pressure equalization chamber and a preheated air chamber within the combustion device, feeding pressurized ambient air to the heat sink/pressure equalization chamber, feeding preheated air to the preheated air chamber, exchanging heat from the lean gas chamber, the preheated air chamber, and the combustor to the pressurized ambient air in the heat sink/pressure equalization chamber, feeding the lean gas from the lean gas chamber to the combustor, feeding the preheated air from the preheated air chamber to the combustor, and combusting the lean gas and the preheated air in the combustor at superatmospheric pressure.