Digital vs Analogue
- Offer better reception of TV services than the analogue system;
- Deliver higher quality picture and sound than analogue, it has no effects of ghosting or distorted pictures;
- Offer enhanced features such as closed captions, electronic program guides, and data services and even selected radio services.
Benefits of DTTB ( Digital Terrestrial Television Broadcasting)
Wide screen Television Picture is a format that allows television networks to broadcast television programs that offer a more natural, panorama view compared to the earlier formats.
Wide screen is sometimes known as “16:9”, this refers to the aspect ratio (the ratio of width to height) of a wide screen picture.
Most new Australian programs, especially sport events and overseas sourced programs, are now produced for widescreen formats.
Minimum Recommended Signal Levels
MER (Modulation Error Ratio)
When measuring digital signals the MER should be one of the main parameters to be measured. Terrestrial MER >32dB.
The reason for this measurement rather than measuring BER, is that BER can be influenced by the forward error correction method incorporated in the digital demodulator. While MER has the advantage that this measurement is before forward error correction, so it gives us a better idea of how the signal and hence how the installation is performing.
BER (Bit Error Ratio)
C/N ( Carrier to Noise Ratio )
The Carrier to Noise Ratio is defined as the ratio between the vision carrier signal level and the RMS noise level.
The carrier to noise ratio for any analogue channel shall not be less than 45dB at any point in the system.
The carrier to noise ratio or SNR (signal to noise) for any digital channel shall not be less than 32dB at any point in the system.
The decibel (dB) logarithmic unit that indicates power or intensity and dBμV/mreferenced to micro volts per metre for radio frequency signal strength.
SNR (Signal-to-noise ratio) is a measure used in science and engineering to quantify how much a signal has been corrupted by noise.
analogue reception 66dBµV C/ N >45dB
digital TV reception 66dBµV SNR >32dB MER >32dB
satellite installation 63dBµV MER>12B
DVB-T (Digital Video Broadcasting — Terrestrial )
DVB-S (Digital Video Broadcasting — Satellite )