EXFO CableSHARK P3 VF/DSL Cable Qualifier - Manual (Page 185)

CableSHARK P3 User Guide
173
Section 9 Spectral Detective
The CableSHARK’s Spectral Detective test allows user to bridge onto a live circuit to measure the Power
Spectral Density Noise of the line. The Spectral Detective measures up to 2.2 MHz (or optional 6 MHz) so
users will be able to characterize loops utilizing ISDN, T1 / 2 MBIT/S (E1), HDSL, HDSL2, ADSL, G.SHDSL,
etc. to determine (a) the technology that is being transmitted over the link and (b) the power associated with
the transmitted technology to ensure it is not disruptive to adjacent pairs and technologies.
+ -
CableSHA RK xD SL C able Q ual if i er
F1 F2 F3 F4 F5 F6 F7 F8
1 2 A B C 3 D E F 4 G H I 5 J K L 6 M N O 7 P R S 8 T U V 9 W X Y 0QZ * #
RU N ST OP
E F C H G
A W or ld of G o od fo r Yo u r N e two rks
S YS T EM S ET U P C A BL E T ES T S D MM T ES T S R E CA L L R E SU LT S 13 : 16: 2 0 F
Central Office
Central Office
+ -
CableSHA RK xD SL C able Q ual if i er
F1 F2 F3 F4 F5 F6 F7 F8
1 2 A B C 3 D E F 4 G H I 5 J K L 6 M N O 7 P R S 8 T U V 9 W X Y 0 QZ * #
RU N ST OP
E F C H G
A W or ld of G o od fo r Yo u r N e two rks
S YS T EM S ET U P C A BL E T ES T S D MM T ES T S R E CA L L R E SU LT S 13 : 16: 2 0 F
Customer
Customer
CableSHARK
bridges onto an
active line
CableSHARK
bridges onto an
active line
Plu s
Pl u s
F IGURE 9A – T HE C ABLE SHARK BRIDGES ONTO A L IVE C IRCUIT
The Spectral Detective provides accurate feedback on PSD shape and power. Users can verify circuits used
in line sharing applications are being properly deployed. Too much transmit power on one circuit can be
spectrally incompatible with adjacent pairs, causing unnecessary truck rolls, frustrated customers, and lost
revenue.
The Spectral Detective test is best performed at the CO or the Customer Premise, where the effects of
NEXT and FEXT can truly be analyzed. Measuring at the crossbox can be useful as well as many
technologies typically converge here before heading to the Customer Premise.