ADC HDSL4 Manual de usuario descargar pdf (Pagina 12)

Table 5: Definitions

Errored Second Any one-second period containing one or more bit errors.

AMI Alternate Mark Inversion is a pseudo-ternary signal conveying binary digits in

which successive "ones" (marks, pulses) are of alternating, positive (+) and negat-

ive (-) polarity, equal in amplitude and in which a "zero" (space, no pulse) is of zero

amplitude.

B8ZS Bipolar with 8-Zero Substitution is a code in which eight consecutive "zeros" are

replaced with a sequence 000+-0-+ if the preceding pulse was a positive (+) and

with the sequence 000-+0+- if the preceding pulse was a negative (-) pulse; zero

represents no pulse.

Straight-away A test configuration where the testing is performed using BERT test sets at both

ends of the circuit or portion of circuit to be tested.

5.1. DB LOSS TEST (USED ON STANDARD SPANS ONLY)

DB loss tests are only required on service orders with non-HDSL copper facilities and on maintenance cases where

non-HDSL copper facilities have been replaced.

To test the end section loss, an un-framed "all ones" 1.544Mb DS1 signal is sent (by the Central Office Technician,

SSIM through CART, or the SSTC remote access) from the serving CO and measured at the customer's Service Inter-

face by the outside Technician. An un-framed all ones signal is used because it leaves the last repeater at the required

772 KHz at 0 db toward the customer.(Loopbacks may be used by the outside field technician.)

Step 1

Send an un-framed "all ones" DS1 signal toward the customer location using a DS1 Bit Error Rate Test Set (BERT).

The Central Office (CO) technician will do this from the local Serving Office DSX-1 frame. The Special Services Test

Center technician will send this pattern when a remote test system is available.

Step 2

At the customer Service Interface, the Outside Technician must connect a BERT Test Set to the receive cable pair.

The test set should be set to measure the receive signal level in dBDsx. See the specific test set manual for setup. The

measured level must be between 0 and -16.5 db at the Service Interface.

5.2. CURRENT MEASUREMENT (also known as Milliamp test) USED

ON STANDARD SPANS ONLY FROM THE NETWORK

INTERFACE/SMARTJACK

Use a volt meter that measures voltage with at least 2 decimal point accuracy. On a smartjack or NCTE measure the

AT&T Practice ATT-TP-000-000-006

Issue 1, 08/25/06

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ADC HDSL4 Manual de usuario Pagina 12