Wegener Communications 6420 User Manual

Page of 135
 
 
iPump 6420 User’s Manual
 
www.wegener.com 
800070-01 Rev B 
Chapter 1, Page 20 
1.6. 
Glossary of Terms and Abbreviations 
Term 
Definition 
AFD 
Assured File Delivery, the WEGENER system for file downloads through 
satellite channels 
Alarm 
An indication of a serious fault, generally expected to prevent the i6420 
from fulfilling a basic mission 
Application 
Term used to describe the controlling software that runs on top of an Linux 
Operating System, and that provides most i6420 functionality. 
ASI 
A physical interface for MPEG Transport streams, featuring bit-serial 
transmission on a baseband signal with 270 MHz signaling rate.  The data 
is sent asynchronously, meaning the interface conveys a data byte when 
available at the sender, and padding bytes otherwise. 
Boot Loader 
A small program that briefly runs on top of the Linux OS in the i6420 that 
loads and runs the main application. 
Carrier 
An RF signal whose envelope and phase is modulated (manipulated) in an 
defined fashion in order to convey information. 
Client 
A program that can be started and ran on a computer that seeks services 
from server programs.  Usually human operators will interface directly 
with the client to seek these services. 
Compel 
WEGENER’s trademark Control system, optimized for control of media 
distribution systems using edge devices such as WEGENER’s iPump 6420. 
DVB 
Digital Video Broadcast.  Term used to represent the methods and 
protocols using MPEG Transport streams to distribute media content over 
satellite 
Eb/No 
In digital carrier systems, the energy per information-bit divided by the 
channels noise density per Hertz.  This is the key figure of merit for signal-
to-noise ratio. 
Ethernet 
The widely-used LAN technology specified by IEEE standard 802.3 
FEC 
Forward Error Correction.  A transformation done on a stream or block of 
information, expressed in bits, bytes, or frames, where some small amount 
of redundancy is added.  This is done in a manner such that, when the 
transformed (FEC-encoded) stream of data is conveyed over error-prone 
communication links, such as satellite channels, the errors can be removed 
and the original information message recovered. 
FTP 
File Transfer Protocol.  Industry-standard method for transferring files 
between host computers over IP networks. 
HTTP 
Hypertext Transfer Protocol.  This is the protocol supported by web 
servers and clients.  It actually describes a set of methods to upload and 
download, not only web pages, but any kind of file.  The i6420 uses the 
HTTP POST method to upload files to remote servers, and uses the GET 
method to download files from remote servers. 
IP 
Internet Protocol.  The internetworking protocol that allows host 
computers to communicated over local networks or over the internet. 
IRD 
Integrated Receiver-Decoder. A product which features a "receiver" to extract 
Transport streams from satellite-borne carriers & a companion "decoder" to 
decompress MPEG elementary streams (from within said transport streams) in 
order to recreate the original audio/video/data signals. The WEGENER Unity 4600 
is an IRD.