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ABBREVIATIONS & TECHNICAL TERMS
• APID (Audio Packet Identifier): Audio reception parameters in the MPEG data stream.
• aBER (Bit Error Rate after Viterbi): Ratio of the transmitted bits to the erroneous bits after Reed
Solomon (Viterbi).
• BCH (Bose Chaudhuri Hocquenghem): External error protection decoder.
• BER (Bit Error Rate): The bit error rate shows the quality of the DVB signals. It displays the number of
erroneous bits in relation to all the transmitted bits.
• bBER (Bit Error Rate before Viterbi): Ratio of the received bits relative to bits that have errors before
Reed Solomon (Viterbi).
• CBR (Constant Bit Rate): Is used for MPTS measurements, cf. VBR.
• C/N (Carrier to Noise): Difference between the carrier signal and noise level in dB; see also S/N.
• EVM (Error Vector Magnitude): Measures deviation of the transmitted symbols to the ideal
constellation, measured in dB.
• FEC (Forward Error Correction): Forward Error Correction, e.g. in case of the code rate ¾, ¾ of the
information is user data, ¼ of the data come from the Viterbi correction.
• Guard Interval: Guard interval by extending the symbol through a gap. Due to this, good reception
is possible even in case of strong reflections.
• LCN (Logical Channel Numbering): Logical channel sorting performed by the provider.
• LDPC (Low Density Parity Check): A new error protection method applied in DBV-S2 (Gallager
codes). Inner error protection; code rates from 1/2 to 9/10.
• MER (Modulation Error Rate): MER is the ratio of the average signal power to the average error
power in dB. It is a kind of a C/N measurement which gives information whether the receiver is able
to demodulate the received signal.
• MPTS (Multiple Program Transport Stream).
• NID (Network Identification): Network ID or channel identification number between 0 and 8191.
• NIT (Network Information Table): Contains, for example, information about all available
transponders, PIDs, downlink frequency, polarisation, next transponder for the scan; transmitted in
the multiplexer transport stream.
• NsMargin (Noise Margin): Signal to Noise Ratio margin.
• OMI (Optical modulation index).
• PER (Packet Error Ratio): The Packet Error Ratio displays the number of incorrectly received data
packets relative to the total number of transmitted packets (after Viterbi).
• QEF (Quasi Error Free): Bit error rate equals 2.00e-4.
• Noise Level: Sum of noise factor and thermal noise floors. Noise is created by physically caused
molecular motion in electrical conductors.
• RMS (Root Mean Square): Method of a square mean value determination.
• S/N (Signal to Noise): Difference between the wanted signal and the noise level in dB; S/N ≈ C/N +
1,5; see also C/N.
• SPTS (Single Program Transport Stream).
• TSID (Transport Stream ID): Transponder/multiplex ID.
• VBR (Variable Bit Rate): Is used for MPTS measurements, cf. CBR.
• VPID (Video Packet Identifier): Video reception parameters in the MPEG data stream.