US 6,650,697 B1 · Wireline communication system and method of frequency allocation therein

Abstract

To alleviate the requirement to back-off all up-link performance, such as by limiting power spectral density, to overcome far-end cross-talk problems otherwise associated with relatively short loop-length wireline links, the present invention partitions the frequency spectrum based on an estimate of the loop length of a subscriber unit (CPE) modem from an exchange (LTE) modem. Up to a threshold frequency (fmax) at which received transmissions from a subscriber having a longest loop length (115) become indistinguishable by the LTE modem from a noise floor (102), up-link performance on all loop lengths is limited to correspond to that of the longest loop. At frequencies above the threshold frequency (fmax), subsets of subscribers (152-154) having relatively short loop lengths (116-119) use high frequency carriers that have signal to noise ratios sufficient to support information transmission in these elevated frequency bands.

Claims19

Dependent claims

A method of allocating frequency bandwidth in a wireline communication network maintaining a plurality of wireline links between a line termination node containing a plurality of collocated modems and a plurality of subscriber-associated modems located at differing loop lengths from the line termination node, the method comprising the steps of:

for each of said plurality of wireline links, estimating a loop length of said wireline link;
arranging said wireline links into at least two subsets of wireline links based on said estimated wireline link loop lengths;
and
partitioning bandwidth on a frequency basis and allocating said partitioned bandwidth to said subsets of wireline links.

1 more element

A method of allocating frequency bandwidth for communication in a wireline system supporting transmissions between a plurality of subscribers and a central node, said transmissions limited to a predetermined maximum power level for the wireline system and wherein the wireline system has a theoretical interference floor, the method comprising:

having regard to the theoretical interference floor, identifying a maximum frequency at which reliable communication is deemed occur between a selected subscriber at a first distance and the central node and transmitting information at the predetermined maximum power level;
attenuating the predetermined maximum power level for transmissions at said maximum frequency between at least a second subscriber at a second distance and the central node when the second distance is shorter than the first distance, thereby to limit interference;
in relation to a second frequency higher than said maximum frequency at the first distance, transmitting information at the predetermined maximum power level;
and
at frequencies intermediate between the first frequency and the second frequency and for subscribers at nominally constant distance from the central node increasing transmit power levels towards the predetermined maximum power level.

2 more elements

Dependencies are inferred from the claim text.

Wireline communication system and method of frequency allocation therein

Life of this patent

Wireline communication system and method of frequency allocation therein

Life of this patent

Abstract

Claims19