Table of Contents
Advertisement
Term
Automated Recovery
The mechanism used when the U4600 is unable to acquire a valid transport stream, loses
(or Recovery)
network control or detects an invalid control stream, or is unable to deliver the required
services using its current settings. The unit automatically begins attempting operations
under "backup" unit settings stored in the presets table until it can return to normal opera-
tion or is stopped by local user command.
Boot loader
Software residing in non-writable zone of flash which executes at unit reset. It will verify
and load the preselected application.
CA
See "Conditional Access".
COMPEL
Wegener's network control software that may be used to manage your U4600 as well as
other hardware.
Conditional Access
Wegener's system for securing the transmitted transport stream from unauthorized
access. It features distribution of ciphered authorizing messages within a special PID.
Upon deciphering in secure processors within the IRD, these messages continuously
update the IRD with the current descrambling key.
DPI
Digital Program Insert. A special message, borne in an MPEG PID associated with a par-
ticular program, that signals the boundaries of ad avails.
DTMF
Dual-Tone Multi-Frequency. Tone signaling system used by the legacy telephone system.
Tone pairs represented each of the keyboard items 0-9, *, and #. This system may be used
to control external cueing equipment.
DVB
Digital Video Broadcast working group. This is a shorthand designation for a group of
industry standards that provide enhancements in the use of MPEG transport streams. (For
example, one DVB standard defined the standard way QPSK-modulated carriers would
convey these streams over satellite world-wide.)
E
/N
Energy-per-bit per Noise density-per-Hertz. This is a unitless ratio that expresses signal-
b
0
to-noise ratio in carrier transmission systems that convey digital data. A quality measure-
ment for any such system is the E
acceptable error rates. This is called the "E
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 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 U4600 may be connected to an Ethernet LAN.
wegener.com
Table 3: Glossary of Terms
Definition
/N
needed to just convey the digital data within
b
0
19
Unity 4600 User's Manual
/N
threshold".
b
0
800032-01 Rev. C
Advertisement
Table of Contents
