System and method for selectable mask for LDSL
View Patent ↗The present invention overcomes various problems by defining two upstream masks (U 1 , U 2 ) and two downstream masks (D 1 , D 2 ) and using a mask selectable system for the long reach digital subscriber line (LDSL), in which a unique modem feature is activated during handshake to automatically check for physical layer status in terms of spectral compatibility and, thus, automatically optimize the boosted mode with the use of the mask selectable system choose the best combination of upstream/downstream masks in any physical layer noise scenario.
1. A DSL system comprising:
mask selection criteria, the criteria comprising:
a weighted ratio of upstream rates and downstream rates; and
a cost function based in part upon the weighted ratio, wherein the cost function is defined according to the relation:
cost
function
=
(
2
x
(
dsrate
(
2
)
-
dsrate
(
1
)
)
dsrate
(
1
)
)
+
(
(
usrate
(
2
)
-
usrate
(
1
)
)
usrate
(
1
)
)
,
wherein dsrate(1) is the downstream rate of a first mask,
dsrate(2) is the downstream rate of a second mask,
usrate(1) is the upstream rate of the first mask, and
usrate(2) is the upstream rate of the second mask; and
a mask-selectable operator configured to select a spectral mask based on the mask selection criteria, wherein the mask-selectable operator selects a spectral mask based in part upon a determination of whether the cost function is greater than a predetermined value.
2. The system of claim 1 , wherein the predetermined value is zero.
3. The system of claim 1 , wherein the predetermined value is zero and wherein, if the cost function is greater than zero, the second mask is selected.
4. The system of claim 1 , wherein the upstream value of the first mask is given by the following relations:
for 0 ≦f< 4 ,U 1=−101.5;
for 4 <f< 25.875 ,U 1=−96+23.4×log 2 ( f/ 4);
for 25.875 ≦f< 60.375 ,U 1=−32.9;
for 60.375 ≦f< 686 ,U 1=max{−32.9−95×log 2
(
f
60.38
)
,
10×log 10[0.05683×( f× 10 3 ) −1.5 ]−3.5};
for 686 ≦f< 1411 ,U=− 103.5;
for 1411 ≦f< 1630 ,U 1=−103.5 peak,−113.5 average in any [ f,f+ 1 MHz] window;
and
for 1630 ≦f< 12000 ,U 1=−103.5 peak,−115.5 average in any [ f,f+ 1 MHz] window.
wherein f is frequency in kHz and U 1 is measured in dBm/Hz.
5. The system of claim 1 , wherein the downstream value of the first mask is given by the following relations:
for 0 ≦f< 4 ,D 1=−101;
for 4 ≦f< 25.875 ,D 1=−96+20.79×log 2 ( f/ 4);
for 25.875 ≦f< 91 ,D 1=−40;
for 91 ≦f< 99.2 ,D 1=−44;
for 99.2 ≦f< 138 ,D 1=−52;
for 138 ≦f< 353.625 ,D 1=−40.2+0.0148×( f− 138);
for 353.625 ≦f< 552 ,D 1=−37;
for 552 ≦f< 1012 ,D 1=−37−36×log 2
(
f
552
)
;
for 1012 ≦f< 1800 ,D 1=−68.5;
for 1800 ≦f< 2290 ,D 1=−68.5−72×log 2
(
f
1800
)
;
for 2290 ≦f< 3093 ,D 1=−93.500;
for 3093 ≦f< 4545 ,D 1=−93.5 peak,average−40−36×log 2
(
f
1104
)
in any [ f,f+ 1 MHz] window; and
for 4545 ≦f< 12000 ,D 1=−93.5 peak,average−113.500 in any [ f,f +1 MHz] window,
wherein f is frequency in kHz and D 1 is measured in dBm/Hz.
6. The system of claim 1 , wherein the upstream value of the second mask is given by the following relations:
for 0 ≦f< 4 ,U 2=−101.5;
for 4 ≦f< 25.875 ,U 2=−96+21.5×log 2 ( f/ 4);
for 25.875 ≦f< 103.5 ,U 2=−36.4;
for 103.5 ≦f< 686 ,U 2=max{−36.3−95×log 2
(
f
103.5
)
,
10×log 10[0.05683×( f× 10 3 ) −1.5 ]−3.5};
for 686 ≦f< 1411 ,U 2=−103.5;
for 1411 ≦f< 1630 ,U 2=−103.5 peak,−113.5 average in any [ f,f+ 1 MHz] window;
and
for 1630 ≦f< 12000 ,U 2=−103.5 peak,−115.5 average in any [ f,f +1 MHz] window,
wherein f is frequency in kHz and U 2 is measured in dBm/Hz.
7. The system of claim 1 , wherein the downstream value of the second mask is given by the following relations:
for 0 ≦f< 4 ,D 2=−101.5;
for 4 ≦f< 80 ,D 2=−96+4.63×log 2 ( f/ 4);
for 80 ≦f< 138 ,D 2=−76+36×log 2
(
f
80
)
;
for 138 ≦f< 276.000 ;D 2=−42.95+0.0214 *f;
for 276 ≦f< 552.000 ;D 2=−37;
for 552 ≦f< 1012 ,D 2=−37−36×log 2
(
f
552
)
;
for 1012 ≦f< 1800 ,D 2=−68.5;
for 1800 ≦f≦ 2290 ,D 2=−68.5−72×log 2
(
f
1800
)
;
for 2290 ≦f< 3093 ,D 2=−93.5;
for 3093 ≦f< 4545 ,D 2=−93.5 peak,average−40−36×log 2
(
f
1104
)
in any [ f,f+ 1 MHz] window;
and
for 4545 ≦f< 12000 ,D 2−−93.5 peak,average−113.500 in any [ f,f+ 1 MHz] window,
wherein f is frequency in kHz and D 2 is measured in dBm/Hz.
8. A selectable mask system comprising:
mask selection criteria, the criteria comprising:
a weighted ratio of upstream rates and downstream rates; and
a cost function based in part upon the weighted ratio, wherein the cost function is defined according to the relation:
cost
function
=
(
2
x
(
dsrate
(
2
)
-
dsrate
(
1
)
)
dsrate
(
1
)
)
+
(
(
usrate
(
2
)
-
usrate
(
1
)
)
usrate
(
1
)
)
,
wherein dsrate(1) is the downstream rate of a first mask,
dsrate(2) is the downstream rate of a second mask,
usrate(1) is the upstream rate of the first mask, and
usrate(2) is the upstream rate of the second mask; and
a mask-selectable operator configured to select a spectral mask based on the mask selection criteria.
9. A selectable mask system comprising:
a plurality of predefined upstream spectral masks;
a plurality of predefined downstream spectral masks;
a mask-selectable operator configured to select a pair of spectral masks from the plurality of predefined upstream and downstream spectral masks based on:
a weighted ratio of upstream rates and downstream rates; and
a cost function based in part upon the weighted ratio, wherein the cost function is defined according to the relation:
cost
function
=
(
2
x
(
dsrate
(
2
)
-
dsrate
(
1
)
)
dsrate
(
1
)
)
+
(
(
usrate
(
2
)
-
usrate
(
1
)
)
usrate
(
1
)
)
,
wherein dsrate(1) is the downstream rate of a first mask,
dsrate(2) is the downstream rate of a second mask,
usrate(1) is the upstream rate of the first mask, and
usrate(2) is the upstream rate of the second mask.