Splitters Comply with TR-127 for VDSL2 Triple Play Applications
Pulse, a Technitrol Company and a leader in electronic component and subassembly design and manufacturing, announced that its SmartER series of splitters has been tested and meet the new TR-127 standard for VDSL2 applications. TR-127 is a technical report developed by the Broadband Forum to ensure the highest quality delivery of voice, data, and video services (triple play) by maximizing the interoperability of splitters and in-line filters with digital subscriber line access multiplexers(DSLAMs) and modems.
Telephone companies are now able to offer triple-play services to their customers. The signals for all three are brought to the home through the phone company's twisted-pair copper telephone line. However, answering a ringing telephone can interfere with VDSL2 signals carrying High Definition Video (HDV) to the consumer's television, causing the television picture to pixelate or degrade. Pulse's high-performance video-grade splitters counteract this ring-trip video degradation and protect the quality of the video service.*
Pulse has implemented a complete test set-up for TR-127 to ensure that its products are fully in compliance with the new standard and has verified that its SmartER ADSL/VDSL splitter modules are fully compliant with the TR-127 standard for VDSL2 applications. Without TR-127 testing during the design phase there is no way to ensure that the splitters are immune to interruptions caused by the telephone ringing, an on- or off-hook receiver, or answering the telephone while ringing. Splitter performance has a big influence on the quality of the video services. Some low-grade splitters can saturate in the presence of high voltages and currents, which means that they no longer prevent noise from interfering with the data packets sent at the same time. This causes data corruption and packet loss. High-grade splitters, like those in Pulse's SmartER line, do not saturate since they meet TR-127.
Under TR-127, central office (CO) and customer premises equipment (CPE) splitters are tested with DSLAMs and modems as part of a full system test as opposed to being tested in isolation. Until the TR-127 standard was published there was no defined or accepted method of testing the quality of video-grade splitters. The TR-127 standard is a 78-page document which has taken more than three years for industry experts to develop.
"By testing the system under real-life conditions, the splitters can be designed to ensure high-quality video service without interruption from the telephone that uses that same line," explained Ronan Kelly, Pulse product engineer. "Splitters are the solution for the ring-trip problem, but only if they are of a high enough quality to meet the TR-127 standards."
Pulse has a chart detailing its Central Office splitter modules, their application, and the level of TR-127 compliance. It can be accessed at: http://www.pulseeng.com/file.php?3677.
The white paper TR-127 Ensures Quality of Service for IPTV can be downloaded from the Pulse website at: http://www.pulseeng.com/file.php?3675.
* Note: Additional technical information and background on the ring-trip issue can be found in the article Tripping the Video Fantastic - Video Splitters May Prevent the Ring Trip Problem, by Greg Gough (Aug 2007), located at http://www.ospmag.com/issue/article/082007-Tripping.