US 7,584,498 B2 · Method and apparatus for enhanced cable modem operation

Abstract

A channel search algorithm is provided for application at a receiving end of a data transmission channel. In the operation of the data transmission channel, information is transmitted by modulation of an RF carrier and the modulation includes an encoding of information bits by symbols selected from a known symbol constellation, with one or more symbol constellations being established in accordance with a known standard. The channel search algorithm is operative to recognize and select a channel carrying an information signal modulated by a symbol constellation other than that established by the standard, and that selection of a channel using a non-standard symbol constellation is made in seamless coordination with the operation of a channel search, in accordance with the standard, for signals modulated by symbol constellations established by the standard.

Claims19

Dependent claims

In a DOCSIS transmission system comprising a plurality of transmission channels wherein at least one of said plurality of channels carries a data signal thereover, a channel search method for finding a data channel available for use by a terminal located at a downstream end of said plurality of transmission channels, said method comprising the steps of:

sequentially scanning at least two selected subsets of said plurality of data channels for a channel having a data signal transmitted at a predetermined modulation protocol;
and
if the data channel scanned for in the preceding step is not found, further sequentially scanning at least one, but less than all, of the selected subsets of the plurality of channels for a channel having a data signal transmitted at other than said predetermined modulation protocol.

In a DOCSIS transmission system comprising a plurality of channels, wherein information is transmitted via one or more data transmission channels among the plurality of channels by a modulation arrangement in which information bits are encoded by symbols selected from a known symbol constellation, and further wherein the symbol constellation used for encoding the information bits is selected from a set of symbol constellations established in accordance with a known standard, a channel search method for application at a receiving end of the data transmission channel comprising the steps of:

sequentially scanning at least two selected subsets of said plurality of channels for a channel having a data signal modulated thereon in accordance with symbols from one of said symbol constellations established in accordance with said known standard (the “data channel”);
upon not finding the data channel in the sequential scanning step, scanning at least one, but less than all, of the selected subsets of the plurality of channels for a channel having a data signal modulated thereon in accordance with symbols from a symbol constellation other than one of said symbol constellations established in accordance with said known standard (the “non-standard data channel”);
and
upon not finding the data channel in the sequential scanning step or the non-standard data channel in the step of scanning at least one of the selected subsets, scanning all of said plurality of data channels for a channel having a data signal modulated thereon in accordance with symbols from one of said symbol constellations established in accordance with said known standard.

1 more element

Dependencies are inferred from the claim text.

Method and apparatus for enhanced cable modem operation

Life of this patent

Method and apparatus for enhanced cable modem operation

Life of this patent

Abstract

Claims19