MELT: Metallic Line Testing for All-Digital Loops

Migration of current network infrastructure towards a Next Generation Network (NGN) architecture creates new opportunities to automate and expand the effectiveness of in-line diagnostics. By replacing legacy PSTN with a single IP-based network for the Voice & Data transmission using the ‘All Digital’ loop approach, the voice signal is packetized at the customer premises and transported as Voice over Internet Protocol (VoIP) packets in the DSL stream. In this new digital network, operators can implement dramatically more effective methodologies to test, diagnose and locate line impairments in the loop. The unique, extremely cost effective and reliable multichannel Metallic Line Testing (MELT) solution with built-in ‘wetting current’ and search tone functions offers sophisticated integrated loop testing features for real-time monitoring of subscriber loop parameters and CPE terminations, with test head accuracy and zero impact on the DSL performance.
The Lantiq MELT solution consists of a 128 channel Line Test Controller (VINETIC™-LTC) and a 16 channel SLIC (Smart SLIC™-T16 or MLT16). The high level of integration featured in the Lantiq MELT solution means that it has no density impact on high channel count DSL linecards.
The chipset supports all DSL technologies (ADSL, VDSL & SHDSL), matches the accuracy of external test heads, and offers an extended feature set compared to traditional PSTN line testing, including features like board production tests and search tone. The MELT solution also supplies the wetting current (small current provided to prevent line oxidation) required to ensure reliable long term operation of the local loop, and allows the operator to perform continuous line testing without requiring that the customer goes offline.
Compared with the current line testing operation, which uses a switching matrix to connect an external test head or a test card, the Lantiq MELT chipset provides a system cost advantage of up to 90 percent. Moreover, the extremely low (negligible) power consumption supports the European Code of Conduct requirements and is fully compliant to the G.LT test standard in ITU.
The MELT solution compliments Lantiq’s established SELT (Single Ended Line Testing) solution for ADSL and VDSL, which already provides loop information to the operator such as SNR, loop length estimation, data rate estimation, bridge tap detection and crosstalk analysis. Lantiq’s SELT solution also provides information on potential RFI disturbers and estimates the line location of any RFI suspected disturbance.
Lantiq’s newest xDSL products, VINAX™ V3 and GEMINAX™ V3, have the VINETIC™-LTC integrated. For migration scenarios, where POTS service is still active, MLT16 ensures high ohmic impedance that does not influence standard POTS services.


Key Features

  • Revolutionary multi-channel line testing solution suitable for "All-Digital" loops

  • PSTN-grade line testing within xDSL access equipment with no impact on the DSL performance

  • Fully compliant to the G.LT test standard of ITU

  • Extremely low (negligible) power consumption (Code of Conduct)

Diagram - DSL linecard with MELT function (based on Lantiq DSL)

Diagram - DSL linecard with MELT function (based on Lantiq DSL)

DSL linecard with MELT function (based on 3-party DSL)

Diagram - DSL linecard with MELT function (based on 3-party DSL)
Product NameSales CodeDescription
VINETIC™-LTC128PEF 39000 HL V1.1128ch Metallic Line Testing Controller for Lantiq DSL
VINETIC™-LTC128/3pPEF 38000 HL V1.1128ch Metallic Line Testing Controller for 3rd party DSL
Smart SLIC™-T16PEF 49000 EL V1.116ch Metallic Line Testing SLIC with integrated multiplexer for pure All-Digital loops
MLT-16PEF 49100 EL V1.116ch Metallic Line Testing SLIC with integrated multiplexer for compatibility POTS-MELT. In migration topologies where POTS is still active. Also suitable for pure All-Digital loops

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