TIA- 876 Questions and Answers Jack Douglass Chair TIA TR30.3 Phil Kyees, Paradyne Vice Chair TIA TR30.3 dsl January 2003

What is TIA-876? ANSI TIA-876, North American Network Access Transmission Model for Evaluating xDSL Modem Performance Statistically accurate portrait of the North American access network Contains all the key elements of the network Compare performance of different models or manufacturers of DSL systems (DSLAMs and modems) or different DSL technologies. –Implement using Hardware Simulator –Implement using Mathematical Simulations

TIA-876 Key Elements of an Accurate Network Model

Performance Comparison of Different DSL Products or Systems Best Performing ADSL System (CO and Remote) Poorest Performing ADSL System (CO and Remote) Won’t operate with RFI All DSL Systems illustrated in this chart are commercially available and will most likely pass TR48. However their real world performance varies widely. TIA-876 brings out these performance differences

Performance Comparison of Different Technologies Operates over about 98% of the Network Model Operates over about 75% of the Network Model Operates at lower line rate for about 72% of the Network Model Operates at higher line rate for about 72% of the Network Model

Why do we need TIA-876 when we have many other DSL testing standards, such as TR48? TR48 is a Go-No-Go test to ensure that a DSL product/system meets certain minimum requirements TIA-876 uses statistically based line (loop and noise impairment) conditions to bring out real world performance differences between DSL products/systems –These performance difference may not be found using the current DSL tests. –TIA-876 goes beyond the tests that are performed in TR48 –TIA-876 includes many real world line conditions that significantly affect DSL performance that are not included in any other test standard

How does TIA-876 enhance DSL experience for the Customer (Home or Business User)? Long term TIA-876 will help improve that over all performance of DSL products/system and the customer experience –Designers, Venders and Manufacturers focus on improving network performance Statistically based loop (14 million loops) and impairment conditions –Competition to perform better on TIA-876 line condition drives industry toward better performing products –The user experience improves and the overall quality of DSL service improves because of better performing products

How can Service Providers use TIA-876? Service Providers can use TIA-876 as a tool to: –Statistically predict field performance –Compare the network performance of a different brands/models DSL Modems, DSLAMs and/or Systems, before deploying them in the field –Select the appropriate DSL technology for line conditions –Determine DSL deployment strategies –Set reasonable tariff expectations –Improve customer satisfaction by selecting the right DSL system or technology the first time Vehicle to provide product engineers with statistical loop and impairment characteristics, so that they can design better performing DSL products/systems

How can designers, venders and chip manufactures use TIA-876? Optimize product design to operate over statistically based line conditions –Focus on real world line conditions Find weakness in design (e.g., susceptibility to RFI, bridge taps, crosstalk from other xDSL technologies, dynamic impairments) Isolate and resolve field problems Use a basis for regression tests for new products and revisions of existing products

The DLSF is focused on TR48. We don’t want to do anything to derail it. TIA-876 is a released standard and requires no additional work on the part of the DLSF TIA-876 should not distract the T&I WG from their work on TR48, since it serves a totally different purpose –TR48 is a go-no-go test –TIA-876 is performance comparison test –TIA-876 Complements TR48 –TIA-876 goes beyond TR48

How can the DSLF use TIA-876? When appropriate TIA-876 can be referenced by the DSLF as the standard method for comparison performance testing of DSL products/systems in a manner similar to the methods for referencing DSL testing standards from other standards bodies (e.g., ITU, ETSI) TIA-876 can be used along with other DSL tests as part of a certification program –Minimum performance criteria can be specified TIA-876 can be used to help drive improved product performance, which will result in an improved customer experience TIA-876 statistically based Loop and Impairment conditions can be used in future DSLF testing standards