Network Technologies DVB-ASI to IP - Manual (Page 77)

ASI-IP-GTW User's Manual
Page 77
format. Three versions exist. IGMPv2 is common today but IGMPv3 is
the next step.
Meta-data: Meta-data is descriptive data that is "tagged" to a movie or
audio clip. Meta-data is essential for the broadcaster.
MPEG2: Moving Picture Experts Group 2. The compression standard
used today on most satellite and cable TV digital broadcasts.
MPLS: Multi-protocol Label Switching. A Quality of Service mechanism
for IP networks that allow IP packets to flow along a predefined path in
a network, improving the reliability and robustness of the transmission.
MPTS: Multi Program Transport Streams. Transport Streams that carry
multiple TV/Radio services.
Multicast: An IP mechanism that allows transmission of data to
multiple receivers. A multicast can also have several transmit sources
simultaneously. In video applications, multicast is typically used to
distribute a video signal from a central source to multiple destinations.
NMS: Network Management System. A system used to supervise
elements in an IP network. When a device reports an alarm, the alarm
will be collected by the NMS and reported to the operator. NMS systems
typically collect valuable statistics information about the network
performance and can warn the operator early.
PCR: Program Clock Reference. A sampled 27MHz video clock used in
MPEG2 Transport Streams. The primary purpose of the PCR is timing
synchronization between transmitter and receiver.
PSI/SI: Program Specific Information / Service Information. This is
information tables (meta-data) that is carried in MPEG2 transport
streams in addition to video and audio. The information carried is
typically service/program IDs, program names, conditional access
information etc.
QAM: Quadrature Amplitude Modulation. A digital modulation type
that is used for transmission of digital TV signals over cable TV
networks. Often referred to as DVB-C.
QoS: Quality of Service. A common term for a set of parameters
describing the quality you get from an IP network: Throughput,
availability, delay, jitter and packet loss.
QPSK: Quadrature Phase-Shift Keying. The digital modulation type
typically used for transmission of digital TV signals over satellite. Often
referred to as DVB-S.
RIP2: Routing Information Protocol v2. A protocol used between
network routers to exchange routing tables and information.
RSVP: ReSerVation Protocol. A Quality-of-service oriented protocol used
by network elements to reserve capacity in an IP network before a
transmission takes place.
RTP: Real-time Transfer Protocol. A protocol designed for transmission
of real-time data like video and audio over IP networks. RTP is used for
most video over IP transmissions.
SDI: Serial Digital Interface. Also known as ITU-R BT.656. A
specification describing how to digitize and transmit uncompressed
video signals. The typical bit rate of an SDI signal is 270Mbit/s.