Viavi HST-3000 Stücklistenhandbuch

Revision 9.0

March 2012

Technical Assistance: 1-866-228-3762 TAC@jdsu.com

HST-3000 VDSL QUICK CARD

WIDEBAND ,038/6(NOISE

Revision 9.0

February 2012

2Technical Assistance: 1-866-228-3762 TAC@jdsu.com

VDSL2 QUICK CARD

Wideband Testing - Wideband Noise

Wideband Testing Deﬁnitions

Before beginning description of the Wideband test feature found on the HST-3000 it is important the techni-

cian has a basic understanding of two main principles.

• Frequency

• Noise

Frequency: Many technicians are surprised to learn the XDSL signals while on the cable are a series of analog

tones. is is an oversimplication of the technology but a very good explanation from a repair standpoint.

XDSL technologies occupy groups or “spectrums” of frequency according to the technology.

For example, ADSL1 utilizes frequencies between roughly 20 kHz (20000 Hz) to 1.1 MHz (1.1000000 Hz).

ADSL2+ doubles the frequency range to 2.2 MHz and VDSL2 is capable, depending on prole, of going to

30 MHz

Ideally, these spectrums of frequencies would travel from end to end on the circuit all at the same “loudness”

or amplitude. However, in reality, frequency loses amplitude at a linear rate. is means that as frequencies

increase, they lose signal strength faster over the same distance.

Consider the following table, which shows loss per kilometer for three frequencies, 1000 Hz, 300kHz, and

772kHz -- as the frequencies increased their corresponding amplitude decreases.

Table: 1 - Frequency vs Loss per Kilometer

Frequency Loss per Kilometer

1000 Hz 1.27 dB

300,000 Hz 17.87 dB

772,000 Hz 22.56 dB

HST-3000 Test Interface

Connect dual tip & ring + ground leads to the mini-banana connectors on the top of the HST as shown be-

low.

Plug in mini-banana

connectors as shown

Revision 9.0

February 2012

Technical Assistance: 1-866-228-3762 TAC@jdsu.com

VDSL2 QUICK CARD

Wideband Testing - Wideband Impulse Noise

Purpose

 e purpose of this test is to identify the presence of intermittent wideband noise that could cause loss of

synch or degrade the performance of the VDSL circuit. is is the same measurement provided in the VDSL

Good Pair Check except that it is performed manually allowing for continuous analysis of noise level. If the

VDSL Good Pair Check fails for Impulse Noise, it is recommended that the manual Impulse Noise test (be-

low) be run for at least 15 minutes for further troubleshooting.

is test is typically run from the SAI / cross box towards the customer premises. Typically, this test is per-

formed with the pair terminated to the same impendence that will be present when the VDSL2 circuit is in-

stalled (100 Ohms). Because impulse noise is intermittent in nature, this test is typically run over a period of

time – again, usually at least 15 minutes or more if an Impulse Noise problem is suspected and requires further

troubleshooting.

Procedure

1. Connect the Tip and Ring test leads from the HST-3000 to the

desired pair. Connect the ground lead to a valid earth ground

reference (connected to HST as shown in the gure on Page 1).

2. Press the Home navigation key, press the Copper soft key and then

selected Wideband TIMS from the menu and press OK.

3. Press the Display soft key on the lower left of the display; select

WB2 TIMS from the pop-up menu and then Impulse Noise from

the cascaded menu as shown to the right.

4. e Wideband Noise measurement screen should now be displayed

(Stopped indication shown at the top of the screen). Before starting

the measurement, follow the next 3 steps.

5. For VDSL loops, the Filter should be J-20K8. To change the lter

selection, press the Actions soft key, select Filter from the pop-up

menu and choose J-20K8 from the cascaded menu.

6. For VDSL loops, the Termination should be 100 Ohms. To change

the termination, press the Actions soft key, select Termination from

the pop-up menu and choose 100 Ohms from the cascaded menu.

7. For VDSL loops, the reshold should be 52 dBr n (-38 dBm). To

raise or lower the reshold, use the Up / Down arrow keys. To

change from viewing the reshold in dBr n to dBm (or visa versa),

press the Action soft key and select Set reshold in dBm (or dBr

n as applicable). e equivalent reshold in mV will always be dis-

played on the screen.

Revision 9.0

February 2012

4Technical Assistance: 1-866-228-3762 TAC@jdsu.com

VDSL2 QUICK CARD

Wideband Testing - Wideband Impulse Noise

Procedure (continued)

8. Press the Start soft key to begin the test the test will run continuously

until the Stop soft key is pressed.

9. e measurement will count the number of hits against the resh-

old recorded in the window directly to the left of the programmed

threshold. It will also count the number of hits 3 dB above and 3

dB below the threshold.

10. If enabled, an audible “Beep” will sound with each hit counted. is

feature can be turned on / o by pressing the Action soft key and

selecting Enable / Mute Sound Eects. e status of this feature is

shown by the speaker icon on the screen.

11. e elapsed time of the test is shown in the window in the upper left

hand of the display.

Run for 15 minutes against a reshold of 52 dBr n (-38 dBm), there

should be < 3 hits. If a greater number of hits occur, a problem exists.

e display of hits 3 dB above and below the programmed threshold

assist in further diagnosis of the problem by giving additional clues as

to the relative magnitude of the hits in reference to the programmed

threshold. For example, if only 3 hits occurred against the 52 dBr n

threshold but there was 1 hit at the 3 dB point above the threshold and

a signicant number of hits at the 3 dB below point, strong consider-

ation should be given to assessing the pair as marginal and investigating

further.

Unwanted impulse noise “spikes” typically come from external sources such as AC power equipment (trans-

formers, generators, etc.) but plant related issues like pair imbalance or potential bonding & grounding prob-

lems are often the root causal factors behind unacceptably high levels of impulse noise. For further trouble-

shooting, the Impulse Capture and Spectral Analysis functions should be used.

Wideband Testing - Wideband Impulse Noise

Revision 9.0

February 2012

Technical Assistance: 1-866-228-3762 TAC@jdsu.com

VDSL2 QUICK CARD

Understanding and Testing Impulse Noise

Impulse Noise can be dened as any burst of noise that exceeds the RMS (Root Mean Squared) level of the

background noise by 12dB (4 times the voltage). A typical noise impulse is much larger than the data signal,

and can destroy successive bits of data. More data is destroyed in a high speed data stream than a low speed

one.

An impulse noise measurement is made by counting the number of impulses exceeding a preset threshold.

Often it is desirable to measure the amplitude distribution of the noise impulses. is is done by counting the

impulses exceeding three dierent thresholds.

Impulse Noise resholds can be measured with either a dBm or dBrn scale

• dBm measures absolute power

• 0 dBm equals 1 mW to the appropriate load

• If the dB power level is doubled the resulting

• reading on the dB scale goes up 3dB

• If the dB power level is halved the resulting

• reading goes down 3dB

• dBr n measures dB above reference noise:

• Reference noise 0 dBr n = -90 dBm

• Scale shows the relationship between dBm and dBrn

e HST-3000 WB2 SIM can measure Impulse Noise resholds by using either a dBm or a dBrn scale.

Either scale is congured for a

• Center reshold - Metallic Standard is -38 dBm or 52 dBr n

• +3/-3 dB above and below center resholds

• Termination - 100 or 135 Ohms - Metallic Standard lter is 100 Ohms

• Filter Types - G or J Filters - Metallic Standard lter is J-20K8

Andere Handbücher für HST-3000

Inhaltsverzeichnis

Andere Viavi Prüfgeräte Handbücher

Viavi

Viavi T-BERD MTS 5800 Bedienungsanleitung

Viavi

Viavi OLP-88 Bedienungsanleitung

Viavi

Viavi OneAdvisor ONA-1000 400G Technisches Handbuch

Viavi

Viavi T-BERD/MTS 5800 Bedienungsanleitung

Viavi

Viavi OSA-4100 Bedienungsanleitung

Viavi

Viavi SmartClass Fiber OLTS-85 Bedienungsanleitung

Viavi

Viavi OTU-8000 Stücklistenhandbuch

Viavi

Viavi T-BERD MTS 5800 Stücklistenhandbuch

Viavi

Viavi OneAdvisor-800 Bedienungsanleitung

Viavi

Viavi SmartClass OLP-85 Series Bedienungsanleitung

Viavi

Viavi T-BERD/MTS 8000 Stücklistenhandbuch

Viavi

Viavi P5000i Bedienungsanleitung

Viavi

Viavi T-BERD/MTS 2000 Bedienungsanleitung

Viavi

Viavi 8100 V2 Series Bedienungsanleitung

Viavi

Viavi FCOMP/-PRO T-BERD/MTS-2000V2 Bedienungsanleitung

Viavi

Viavi T-BERD MTS 5800 Stücklistenhandbuch

Viavi

Viavi T-BERD/MTS 8000 Bedienungsanleitung

Viavi

Viavi Smart Class 4800 Bedienungsanleitung

Viavi

Viavi SmartClass FBP-OLP-82 Bedienungsanleitung

Viavi

Viavi T-BERD/MTS 5800 Bedienungsanleitung

Viavi

Viavi T-BERD/MTS-4000 v2 Stücklistenhandbuch

Viavi

Viavi SmartOTDR Stücklistenhandbuch

Viavi

Viavi OneAdvisor ONA-800 Stücklistenhandbuch

Viavi

Viavi OneAdvisor 1000 Bedienungsanleitung

Beliebte Prüfgeräte Handbücher anderer Marken

SMART

SMART KANAAD SBT XTREME 3G Series Bedienungsanleitung

Agilent Technologies

Agilent Technologies BERT Serial Bedienungsanleitung

Agilent Technologies

Agilent Technologies N3280A Bedienungsanleitung

Lifeloc

Lifeloc R.A.D.A.R. Bedienungsanleitung

Fluke

Fluke T5-600 Bedienungs- und Montageanleitung

Mercury

Mercury TSL01 Bedienungsanleitung

MAHA

MAHA MBT Series Bedienungsanleitung

Fuji Electric

Fuji Electric P-61 Bedienungsanleitung

ETC

ETC SealerAtor Bedienungsanleitung

Skyfine

Skyfine ETHYWAY V2 Bedienungsanleitung

Appion

Appion G5 Twin Bedienungsanleitung

PCB Piezotronics

PCB Piezotronics 8159-0112A Bedienungsanleitung

BW Technologies

BW Technologies MicroDock II Bedienungsanleitung

Sun Nuclear

Sun Nuclear 1027 Bedienungsanleitung

Biomark

Biomark HPR LITE READER Bedienungsanleitung

Hioki

Hioki 3169-20 Bedienungsanleitung

Ashcroft

Ashcroft ATE-100 Bedienungsanleitung

Rohde & Schwarz

Rohde & Schwarz RTA4000 Bedienungsanleitung