Kathrein UFD 520 manual Short technical lexicon, AC3

Short technical lexicon

AC3	Audio coding MPEG 2/layer 3 - The scrambled digital sound signal for Dolby Digi-
	tal. It transmits 5 sound channels and one reduced sound channel for the sub-
DiSEqC	woofer.
	DiSEqC (Digital Satellite Equipment Control) is a communication system between
	the Sat receiver (master) and the peripheral Sat components (slaves), such as
	LNBs, multi-switch, motorised antenna systems.
	This is a single master/multi-slave system, i.e. there is always only one master in
	the Sat system. All activities emanate from the master.
DiSEqC components	When DiSEqC switchover matrices are cascaded, the master receiver must send
	out the DiSEqC signal several times so that all DiSEqC multi-switches in the cas-
	cade receive their commands.
	Nowadays, DiSEqC components (slaves) must be retrocompatible, i.e. they must
	also respond to the analogue switching criteria of receivers which are only
	equipped with the control signals H/V and 22 kHz.
	A DiSEqC switchover matrix operates with analogue switching criteria until the
	DiSEqC command is received from the master. All analogue switching criteria are
	then ignored.
DVB MPEG-2	DVB is the abbreviation for digital video broadcasting. DVB-S refers to the type of
	transmission (S=satellite). MPEG is the abbreviation for Moving Picture Experts
	Group, a working group which draws up internationally valid standards for the digi-
	tal compression of video together with audio. MPEG-2 has been promoted to the
	standard for the compression of digital TV signals. MPEG-2 operates at a data rate
	of up to 100 MBit/s.
Eb/No ratio	The Eb/No ratio is a measure for the signal-to-noise ratio of the digital signal. This
	value is not identical to the C/N value as known from analogue reception technol-
	ogy. As a rule, reception is no longer possible at Eb/No levels below 5 dB.
FEC	FEC is the abbreviation for Forward Error Correction. The FEC error rate corre-
	sponds to the viterbirate.
PID	The PID number (Package Identification) is an identification number for video sig-
	nals and audio signals in the digital data stream of DVB MPEG-2 signals. The re-
	ceiver uses the PID number to establish distinct allocation of the video and audio
	data transmission. PID-PCR is the identification number for the synchronisation
	signal. PID-PCR is normally identical to PID video. In the case of multi-language
	channel transmissions, by means of manual entry of the audio PID, it is possible to
	allocate another language to the TV broadcast. After entering the PID, the digital
	receiver automatically selects audio data from the data stream identified by the PID
	number and allocates these data to the video signal.
Programme package	The programme package of a digital transponder mostly contains several TV and
	radio channels. Each channel package has a fixed allocation with regard to the
	transponder transmit frequency, the polarisation (horizontal or vertical), the symbol
	rate and the viterbirate or error rate.

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