How the Alcatel-Lucent 5530 NA works
Embedded line testing technologies
The
The Single Ended Line Test (SELT) is a reflectometric test mainly aimed at measuring line length and locating line problems. Consequently, it is used for the estimation of potential line capacity or for the location of possible line impairments.
The Dual Ended Line Testing (DELT) is based on the exploitation of DSL physical layer parameters. DELT testing identifies issues on the higher line frequencies, and enables the detection of problems such as bad contacts, interference, unbalanced loops, etc.
The
Figure 5. Comprehensive line testing technologies
| Loop not synchronized | |
SELT |
| |
(Broadband | Reflectometry | |
spectrum) | ||
| ||
DELT |
| |
(Broadband | ||
spectrum) | ||
| or loop diagnosis mode | |
| xDSL2 LT | |
NBLT | Inward | |
Outward testing: loop/phone | ||
(Narrowband | ||
spectrum) |
| |
| POTS LT |