Although most of the TV products are delicately designed to receive digital and analogsignals, the error rate can still appeared to be high when put the TV into actual test atdifferent countries and regions. For example, we put the same TV in Germany and Spain that the TV works fine in Germany but is having EPG issue in Spain. This is most likely caused by the variation of the broadcasting system in each country. Different carriers use different stream formats and often lead to different results. All these issues can bring TV manufacturers extra challenges in sustaining the claim of product quality. Although field test may be able to eliminate potential error, but it is rather time and cost consuming to most of manufacturers. One big task for the TV makers is to plan a feasible and effective way to validate the RF signal from each and every country for their product.
A new way of RF stream recording technology is introduced to the TV manufacturers, and it is proven to be the revolutionary method to solve the problems. Signal collected from cities of all over the world are systematically centralized and integrated in the labs. These RF signals enable users to test their TV in an intended simulation experience as if they are in the local cities. We have chosen three branded TVs from the market and test against the RF signals recorded from different cities. Errors observed indicate that
different RF streams will cause different results in the same TV. Here is the test result summary.
1. TV Signals Collection & RF Surfing Technology: Through this new technology, TV RF signals can be fully recorded and saved as the IQ format (TV RF raw data). Compare to the TS (Transport Stream) format, IQ format contains not only the environmental factors, but also retain complete parameter. The TS format is the signal re-structured by demodulator, some of the related features are lost during the process. In this test, Allion uses the signals collected from eleven cities in the USA.
2. Selecting TV Device (DUT): We selected TVs which are sold in North America that
support ATSC system. The goal is to verify if the TV can work with selected
3. Testing: Send the TV signal to TV, and perform the following checks after TV
receives the stream.
- Tuner Performance Test
We used auto scan and/or manual scan function to scan through all TV
streams to verify if the DUT can recognize the TV streams we collected. We
also adjusted the intensity of the signals to check the sensitivity of DUT.
- A/V Performance Test
To verify the audio and video quality of DUT and to assure that audio
synchronizes with video.
- Stream Data Performance
To verify the displaying functions of DUT, such as Channel Title, Program Title,
Program Description, Program Duration, Caption Service, Aspect Ratio and
Below statistical analyses show the pass rate of the DUT when connecting to different
streams from specific city. From the test result we can see that Sony KDL-32L4000 has
better performance than Samsung LN-T3253H and Sharp LC-32GP1U.
Across three tested TVs, we found that the tests on the streams of Philadelphia have more failure than the streams from other cities. We summarize the issues for your information.
In this case study, we realize that even the well known branded TV can have the compatibility issues when receiving signal in different countries or regions. To thoroughly locate all possible issues, we need a complete set of signal source data pool.
The testing result in one region does not guarantee that the TV will function properly in ther regions.
Copyright by Allion
The Copyright of this report belongs to Allion Test Labs and permission should be obtained from Allion Test Labs prior to any prohibited reproduction, quotation. Judgment or opinion concerning the results of this test is left to the convenience of the reader and Allion Test Labs do not bear any responsibility in case of secondary damage occurred by using this report.
* The purpose of this report is for marketing research and information sharing only; all DUT models used herein were selected and purchased from the consumer market.