The DSL Forum's “TR-048 ADSL Interoperability Test Plan” is a key milestone in transitioning the distribution of ADSL customer premise equipment to a retail model and bringing ADSL services to the global mass market. TR-048 defines a set of test criteria and benchmarks that an ADSL CPE or DSLAM must meet in order to be compliant to the specification. The importance of this specification is reinforced as the ITU is adopting TR-048 as a requirement for the next generation ADSL Standard, ADSL 2 (G.992.3/4).

Currently major service providers are requiring that devices pass TR-048 before considering them for deployment in their networks. In the near future Network Equipment Manufacturers (NEMs) will be required to have their products certified by an Independent Test Laboratory.

Spirent offers the only complete solution for testing an ADSL device to TR-048. Spirent's solution consists of the DLS 400IA/IAE Wireline Simulator, the DLS 5200IA Noise Generator, and the SmartBits™ SMB 200/2000 Data Generator/Analyzer and is controlled by the DLS 1400 TR-048 Automated Test Software using ScriptCenter ™. This provides the high accuracy, control, consistency, repeatability and automation that NEMs will need to prove product interoperability to ADSL Service Providers. With integrated layer 1, 2, and 3 testing tools, Spirent's solution will play a key role in helping the DSL industry in achieving its’ goals of interoperability and retail distribution.

A small variation in bit rate can mean a difference between passing and failing TR-048. Issues of noise floor, accuracy and repeatability are key technical issues that must be considered. In response to this, Spirent has developed 2 wireline simulation solutions: the DLS 400IA for Cluster A (North America) and the DLS 400IAE for Cluster A & B (North America and Europe). These solutions offer all of the loops required for testing to TR-048.

Both the DLS 400IA and the DLS 400IAE include the latest technology in wireline simulation hardware and software. A key supporting product for the DLS 400IA/IAE is the DLS 1310 Compensation and Fine Data Rate Adjustment Engine which ensures the simulator meets the accuracy, repeatability and requirements specific to TR-048.

Customers who have a DLS 400A/N/HN can upgrade to the DLS 400IA/IAE system, which includes the additional testloops and software compensation package.

Real world noise has a dramatic impact on the performance of ADSL modems and DSLAMs. TR-048 has captured many of the worst-case scenarios and specified a set of crosstalk, RFI*, impulse and white noise test requirements. TR-048 also specifies that these impairments are to be generated with a MAE of less than 0.5 dB with “fine data rate compensation” and less than 1.0 dB without this compensation.

In response to these requirements, Spirent has developed the DLS 5200IA TR-048 Noise Impairment System. The DLS 5200IA provides all of the impairments specified in TR-048 including RFI and applies them as required, within accuracy requirements, in either common* or differential mode to the wireline. Other features include “design your own noise shape” capability for both PSD and time domain noise files, a bandwidth from 12KHz to 12.5MHz, automation via Ethernet control and ETSI / ANSI compliant crest factor.

For customers not concerned about RFI or common mode noise injection and less concerned with high accuracy, the use of two DLS 5A01H Noise Impairment Generators, together with noise files from the DLS 5A17 TR-048 Noise File CD-ROM, will allow for most TR-048 tests to be performed.

* Requirement that is currently under study by TR-048.

Using the unique capabilities of the 10/100 Ethernet and ATM SmartCards, SmartBits™ allows for unparalleled end-to-end stability, frame loss, and latency measurements up to full wire rate.

In reviewing the results of TR-048 ADSL interoperability tests, the analyst is faced with the daunting task of trying to determine the effect of measurement error on their test results. Clearly, a measurement error that results in a ± 1 bin (32 Kbps) performance variation or “bias” can mean the difference between a pass or fail for the modem or DSLAM under test.

To compensate for measurement error, DSL Forum has defined in Annex A of TR-048 a “fine data rate adjustment that allows for measurement compensation of systematic errors caused by test equipment tolerances and laboratory based environmental conditions such as cable lengths and RFI.

In support of TR-048, Spirent Communications has developed the “DLS 1310 Compensation and Fine Data Rate Engine”; a simple to use software based analysis tool that compares setup test results to expected values and provides wireline length compensation data. This tool is recommended for use on a regular basis, prior to any extensive tests that must be performed.

The new TR-048 Interoperability Test Specification from DSL Forum has created a wave of demand for unprecedented accuracy in ADSL testing involving the local loop. Spirent now offers upgrade paths for its most popular ADSL Wireline Simulators to meet the testing demands as required by TR-048 Interoperability Specification. Spirent appreciates that while labs know upgrades translate into the competitive edge for new products, the time it takes to get an upgrade done can be equally critical. There are now three different ways to get upgrades depending on your needs.

Overview
The new TR-048 Interoperability Test Specification from DSL Forum has created a wave of demand for unprecedented accuracy in ADSL testing involving the local loop. Spirent now offers upgrade paths for its most popular ADSL Wireline Simulators to meet the testing demands as required by TR-048 Interoperability Specification. Spirent appreciates that while labs know upgrades translate into the competitive edge for new products, the time it takes to get an upgrade done can be equally critical. There are now three different ways to get upgrades depending on your needs.

1. On-site Upgrade Program:
To minimize testing downtime for customers, Spirent offers the DLS400IA
on-site service upgrades for qualified customers. In this service program, Spirent will send a certified Customer Service representative to a customer's site to perform the upgrade to a DLS 400IA.

Qualifying information:

• There are a minimum of two DLS 400IA upgrades required for a on-site upgrade, up to a maximum of five upgrades.
• 2.5% discount on 2-3 units, 5% discount on 4-5 units off the per unit price.
• Travel and living expenses are included in these service packages.
• Units which are over 6 months past their last valid calibration date (must have been calibrated by Spirent, or an authorized service provider) will be subject to a surcharge.
• 6 weeks lead-time is required to schedule an on-site upgrade.
• The customer needs to provide access to all units on the scheduled dates and times (Spirent Customer Service Manager will assist in preparing a "working schedule" for the visit).
• Access to units includes:
  Units disconnected from any other equipment, access to any secure areas, work bench (4’x8’), six power outlets. The customer is to provide a static free lab work environment for the on-site service work.
• Available in North America and Europe (some restrictions apply in Europe).

2. Factory Upgrade With A Loaner DLS 400IA Program:
For customers requiring immediate need of a DLS 400IA system or to reduce any downtime during the upgrade of a customers DLS 400 unit, Spirent offers DLS 400IA loaner programs. Spirent will ship a DLS 400IA system to the customer site to be used during the time that the customers unit is being upgraded.

Qualifying information:

• Please contact Spirent for a Returned Material Authorization (RMA) number.
• DLS 400IA loaners are scheduled based on availability.
• Spirent covers shipping cost of the loaner unit to and from the customer.
• Available in North America and Europe (some restrictions apply in Europe).
• The loaned DLS 400IA unit must be returned within 2 days of receipt of the newly upgraded customer's DLS 400IA system.

3. Basic Factory Upgrade Program:
A customer may simply send in a DLS 400 unit to the factory for upgrade.

Qualifying information:

• Please contact Spirent for a Returned Material Authorization (RMA) number.

Part Numbers:

On Site Upgrade Program:
DLS-9610 Upgrade From (DLS 400HN/H/N/Micro-Interrupt) to a (DLS 400IA)
DLS-9611 Upgrade From (DLS 400HN/H/N) to a (DLS 400IA)
DLS-9612 Upgrade From (DLS 400A) to a (DLS 400IA)

Factory Upgrade With A Loaner DLS 400IA Program:
DLS-9613 Upgrade From (DLS 400HN/H/N/Micro-Interrupt) to a (DLS 400IA)
DLS-9614 Upgrade From (DLS 400HN/H/N) to a (DLS 400IA)
DLS-9615 Upgrade From (DLS 400A) to a (DLS 400IA)

Basic Factory Upgrade Program:
DL4-400IA2 Upgrade From (DLS 400HN/N/Micro-Interrupt) to a (DLS 400IA)
DL4-400HN/N-IA Upgrade From (DLS 400HN/N-IA) to a (DLS 400IA)
DL4-400A-IA Upgrade From (DLS 400A ) to a (DLS 400IA)

The full range of upgrade programs are also available for the DLS 400IAE.
Please contact customer service for more information.