text stringlengths 0 1.99k |
|---|
The basics of LMOS have been covered in part I. Part II will take a |
closer look at the Mechanized Loop Testing process and its relation with LMOS. |
As mentioned previously, the equipment for the MLT system is located in |
or near the Central Office or End Office in which the customer loops |
terminate. The MLT equipment (being a third generation of automated testing |
system) is connected by test trunks through the switching system to customer |
loops. The MLT controller located in the Repair Service Bureau enables tests |
to be made on up to 12 local loops simultaneously, sets up the testing |
sequence, and controls the connection of test equipment to the loops. To make |
the appropriate tests, information in the LMOS data base(s) about the customer |
loop and station equipment is transmitted to the MLT controller when the test |
request is initiated. This information controls certain phases of each test |
and is used to analyze and decipher test results. |
On command from the MLT controller, which will now be referred to as |
simply 'the Controller', the MLT system dials the number to be tested. If the |
line is busy, the cause is automatically determined (a conversation, phone |
off-hook, or a fault), and further tests are not made until the line is free. |
If the line is idle, the MLT system proceeds to make tests for purposes of |
maintenance and detection of faults in the loop. |
MLT test specifics |
* AC and DC (Alternating Current and Direct Current) measurements to determine |
if the loop is proper for the customer's station equipment, to determine the |
type and the extent of any electrical leakage through cable insulation, and to |
detect broken cable pairs and the location of the break in terms of distance |
from the CO where MLT is being used. |
* A 'Soak Test' to see if leakage will disappear after a high voltage is |
applied from the Central Office battery. The voltage dries up moisture, which |
is a frequent cause of leakage. |
* A Balance Check to reveal how susceptible the loop is to noise causing |
voltage, which would impair conversation over the line. |
* A measurement to tell whether CO battery voltage (voltage drops when the |
phone goes to an off-hook condition) and dial tone can be placed on the loop. |
All MLT test measurements are converted by the MLT hardware to digital |
form and returned to the Controller for analysis. The analysis is based on the |
test results and the line-record info from LMOS. |
Here is an example of how the Automated Repair Service Bureau (ARSB) |
works with the repair service attendants. A customer can't get a dial tone, so |
he calls the repair service from a neighbor's phone. An attendant who answers |
the call types the customer's phone number into a computer terminal. In |
response to this, LMOS displays the customer's name, address, class of service |
(in this case, it would be residential service), and information about any |
recent trouble on that loop. At the same time, LMOS causes the MLT system to |
test the loop. The CRSAB Attendant types in a description of the reported |
trouble. The MLT system returns the results of the tests on the line within a |
few seconds. Say, for example, the fault in question was a cable fault. This |
information would be displayed on the screen. The attendant would tell the |
customer that a visit is not needed, and that line will be repaired by a |
certain time. The data on the screen is automatically added to the LMOS |
database. A BOR is printed in the RSB serving the customer, and is screened to |
decide if it should be given to a dispatcher or a tester. The content of a BOR |
is explained in part one, and a diagram of a BOR is included below. |
**** BASIC OUTPUT REPORT ***** PAGE- 01 |
UNIT-99900000 10-08-86 0300P TTN-0000110 |
TN-999 5557009 CAT-CD |
SC-1FR CS-RES PUB CPE-NO SWC- WKNG -0- |
SMITH, JOHN |
1000 NOWHERE LN. |
--RMKR-- |
--TRBL--NDT-CCO-CBC-ALL CALLS |
--RCH-- REACH NBR- |
COMM-10-09-86 0700P VER-4 CALLED NBR- OVER- |
STATUS-PS 10-09-77 0400P |
--STATUS NAR-- |
SO DATE 03-27-85 SO# N0901 |
--S/E-- |
QTY-0001 USOC-1FRBC KS-0000 LTD- REF- |
--ASGM-- |
OE-000B-010-09 VT-0146 RT-0500 NSTA-0001 BRG-N NSV-N |
WC-999 F1 NPA-999 CA- TT101 PR-109 PRU- BP-10 |
TEA-R1304 NOWHERE LN. |
--HIST-- |
NO REPORT SUBS CLEARED TH-KEY TST RPM O/S } T } D } C } |
1 10-01-85 205P 0 10-02-77 0130P 10-02-77 620P 110 111 * }330}320}320} |
REPLACED INSIDE WIRE |
------------------------------------------------------------------------------ |
MLT RESULTS SUMMARY: OPEN OUT, DISTANCE TO OPEN=39,200 FT |
OPEN OUT |
OPEN TIP |
DISTANCE TO OPEN |
39,200 FT (FROM C.O.) |
VALID DC RESISTANCE AND VOLT |
VALID LINE CKT CONFIGURATION |
CAN DRAW AND BREAK DIAL TONE |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.