SVP UDR-70, Руководство пользователя

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UDR-70 H.265 Portable Receiver
USER’S MANUAL V1.0
D.3. DVB-S
DVB-S is the first generation of a standard for digital
broadcasting via satellite.
D.3.1. How Does It Work
DVB-S was designed to carry MPEG-2 transport streams over satellite.
MPEG-2 transport streams typically carry one or several television or
radio services multiplexed into a synchronous bit stream. All service
components are divided in short packets of 188 bytes, each identified
by a Program Identifier in the header of the packet.
Generic data can also be carried in MPEG transport streams, provided
that it is first encapsulated in the transport stream packets. The most
common way to encapsulate IP data into MPEG streams is called Multi
Protocol Encapsulation (MPE) and is also specified by a DVB standard.
The total bit rate of the transport stream is constant but can typically
be adjusted to match the needs of the satellite link. If the desired
transport stream rate is greater than the sum of the carried
components, empty packets are added to the stream by the
multiplexer or the modulator. This operation is called rate adaptation.
DVB-S uses QPSK modulation and concatenated error protection
based on a convolutional Viterbi code and a shortened Reed Solomon
code.
Figure 112: Future Extension Frames