User`s manual

Unity 4650 User’s Manual
wegener.com 21 800034-01 Rev. A
Extended windows Where decompression of 4:2:2 chroma sampled MPEG video is supported, the original
encoder may be set to compress Vertical Blanking Interval (VBI) data in the same manner
as the video in the active picture area. This mode where extra vertical resolution is sup-
plied, is called Extended Windows by Wegener. The term Standard Windows designates
systems where only the active picture area is compressed and the VBI must be trans-
ported by some other method.
Fade Generic term used to describe loss of RF carrier and subsequent loss of transport stream.
The loss of the carrier is inferred when carrier tracking in the receiver card ceases. If the
transport input comes from a terrestrial interface (e.g. ASI), the loss of the transport is
still termed a fade. Fade is also assumed if either (1) the errored second rate or (2) the
continuity count rate exceeds alarm thresholds.
Flash memory A type of non-volatile memory characterized by block erasures, special block writing
techniques, and random-access reads. Generally, semi-permanent objects such as applica-
tion software code are stored to flash. However, because the reads are slow relative to
standard SDRAM, the software must be relocated to SDRAM before execution.
Genlock The process of aligning the presentation timing of the IRD’s video output to the timing
reference in the station plant. This allows for seamless switching between the IRD’s
video output and other "genlocked" videos.
Ghost PID PIDs which do not convey well-known ISO/DVB/ATSC tables and which are not refer-
enced by any program's PMT.
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 4650 is an IRD.
Keep-alives
(COMPEL)
Simple COMPEL network messages, addressed to "all", bearing date and time.These are
transmitted regularly (every 5 seconds, for example) so that IRDs may quickly and con-
tinuously verify their network connection.
KMS Key Management System. The sub-system within the Wegener Conditional Access sys-
tem 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 U4650 may be connected to an Ethernet LAN.
LCD Liquid crystal display. The front-panel screen on your U4650 is a liquid crystal display.
LED Light-emitting diode. The front-panel indicator lights on your U4650 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 4650 utilizes the MPEG2 format for video.)
Table 3: Glossary of Terms
Term Definition