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Jan 25 2010

New RF Stream Technology Reveals Compatibility Issues

Using the new RF stream recording technology, Allion designed a test to assess the level of television compatibility in the United States. RF signals were collected from 11 cities: Baltimore, Chicago, Dallas, Elgin, Englewood, Fargo, Los Angeles, Milwaukee, Minot, Newark and Philadelphia.

We chose three major TVs sold in North America that support the ATSC system:

  • Sony LC-32GP1U
  • Samsung KDL-32L4000
  • Sharp LN-Y3253H

Allion’s RF Stream Tests
For the testing, Allion sent the variety of RF signals collected to the TVs, and once the stream was received, we performed a series of checks to assess performance. We scanned all TV streams to verify that the streams were being recognized, while adjusting the intensity of the signal to determine the TVs’ sensitivity. We verified the audio and video quality, as well as audio/video synchronization. For stream data performance, we verified the display functions, including the channel and program title, caption service, aspect ratio and EPG information.

Our  Findings
While the Sony had better overall performance than the Samsung and Sharp, we found compatibility problems across the board. The errors we found included mosaic pictures, double subtitles, scrambled text and broken images. Regarding the locales tested, Philadelphia had more failure than other cities, while Milwaukee had 100 percent performance from all three brands.

This case study demonstrates that even major TV brands can face compatibility issues. The field testing that TVs undergo prior to going to market is insufficient to guarantee consistent quality when receiving signals from different regions or countries.  By offering a data pool of signals, Allion’s Real World TV Validation testing helps locate and prevent all possible compatibility issues.