Wegener Communications 4600 manual Ird, Compel, Kms, Lan, Lcd, Led, Mpeg, Ntsc, Pal, Pat, Pcr

		Unity 4600 User’s Manual
	Term	Definition
	Ethernet	The widely-used LAN technology specified by IEEE standard 802.3
	IRD	Integrated Receiver-Decoder. A product which features a "receiver" to extract transport
		streams from satellite-borne carriers and a companion "decoder" to decompress MPEG
		elementary streams (from within said transport streams) in order to recreate the original
		audio/video/data signals. The Unity 4600 is an IRD.
	Keep-alives	Simple COMPEL network messages, addressed to "all", bearing date and time.These are
	(COMPEL)	transmitted regularly (every 5 seconds, for example) so that IRDs may quickly and
		continuously verify their network connection.
	KMS	Key Management System. The sub-system within the Wegener Conditional Access system
		that creates and ciphers the scrambling keys and then distributes them to the uplink
		UMX5010 and all downlinked IRDs conveyed in a special PID within the transport stream.
	LAN	Local area network. Your Unity 4600 may be connected to an Ethernet LAN.
	LCD	Liquid crystal display. The front-panel screen on your Unity 4600 is a liquid crystal display.
	LED	Light-emitting diode. The front-panel indicator lights on your Unity 4600 are LEDs
	Mbps, kbps or Msps	Units of data transport rate - Megabits per second (1 million bits per second), kilobits per
		second (1 thousand bits per second), or million symbols per second (1 million symbols per
		second)
	MPEG	Moving Picture Experts Group - refers to the method of video compression established by
		this group. (The Unity 4600 utilizes the MPEG2 format for video.)
	Network Protection	A non-volatile setup parameter whose value is “Shared” or “Protected” (or “not Shared”).
	Mode	Similarly, each network control stream has a “Share” status field as part of the COMPEL
		packet framing. A network control stream is considered “invalid” to the Unity 4600 if the
		network ID in the stream differs from that of the IRD and if either the network stream or the
		Unity 4600 are set to be “Protected”. For test purposes only, there is a generic network ID
		that the COMPEL system may transmit which is always considered to be “valid” by all IRDs.
	NTSC	National Television System Committee. The composite color video standard used
		domestically (and in a few countries outside US) based on 525-line 59.97 Hz field rate (with
		2:1 interlace).
	PAL	Phase-Alternating-Line. A set of composite color video standards used worldwide (outside
		US) which implements a line-by-line reversal of phase of one of the orthogonal color
		components. For our use, all PAL signals are assumed to be 625-line 50 Hz field-rate
		systems with varying chroma and luma bandwidths and color subcarrier frequencies.
	PAT	Program Allocation Table. A PSI table within an MPEG transport stream which cross-
		references all available programs to a PID for its PMT. This table is always present in legal
		transport streams and must always be in the clear (not scrambled) even when Conditional
		Access scrambling is used.
	PCR	Program Clock Reference. A time-base signal used to synchronize the IRDs internal timing
		to the same timing in the MPEG encoder for the received program. Multiple programs may
		share a PCR, depending on the multiplexer used to create the final transport stream.
	PES Stream	Packetized Elementary Stream. The MPEG designation for a compressed component of a
		Program (such as audio or video) which includes the timing information necessary for
		synchronization (e.g. - synchronizing audio to video).
	PID (or Packet ID)	The unique transport stream packet identifier assigned to each constituent data stream
		within the transport stream. Also, in this document, “PID” is used to designate the stream
		itself.
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