SSH EN 301 192 V1.2.1:1999

Transmetimi Dixhital Video (DVB); Specifikimi DVB për transmetimin e të dhënave

Digital Video Broadcasting (DVB); DVB specification for data broadcasting

Scope

The present document is designed to be used in conjunction with EN 300 468 [2] and ETR 211 [4]. The DVB System
provides a means of delivering MPEG-2 Transport Streams (TS) via a variety of transmission media. These TSs have
traditionally been oriented to containing MPEG-2 Video and Audio. Data broadcasting is seen as an important extension
of the MPEG-2 based DVB transmission standards. Examples for data broadcasting are the download of software over
satellite, cable or terrestrial links, the delivery of Internet services over broadcast channels (IP tunnelling), interactive
TV etc. Four different application areas with different requirements for the data transport have been identified. For each
application area a data broadcasting profile is specified in the present document. The following is a short description of
the application areas and the profiles.
Data piping
- The data broadcast specification profile for data pipes supports data broadcast services that require a simple,
asynchronous, end-to-end delivery of data through DVB compliant broadcast networks. Data broadcast according
to the data pipe specification is carried directly in the payloads of MPEG-2 TS packets
(see ISO/IEC 13818-1 [1]).
Data streaming
- The data broadcast specification profile for data streaming supports data broadcast services that require a
streaming-oriented, end-to-end delivery of data in either an asynchronous, synchronous or synchronized way
through DVB compliant broadcast networks. Data broadcast according to the data streaming specification is
carried in Program Elementary Stream (PES) packets which are defined in MPEG-2 Systems
(see ISO/IEC 13818-1 [1]).
- Asynchronous data streaming is defined as the streaming of only data without any timing requirements
(e.g. RS-232 data).
- Synchronous data streaming is defined as the streaming of data with timing requirements in the sense that the data
and clock can be regenerated at the receiver into a synchronous data stream (e.g. E1, T1). Synchronized data
streaming is defined as the streaming of data with timing requirements in the sense that the data within the stream
can be played back in synchronization with other kinds of data streams (e.g. audio, video).
Multiprotocol encapsulation
- The data broadcast specification profile for multiprotocol encapsulation supports data broadcast services that
require the transmission of datagrams of communication protocols via DVB compliant broadcast networks.
The transmission of datagrams according to the multiprotocol encapsulation specification is done by
encapsulating the datagrams in DSM-CC sections (see ISO/IEC 13818-6 [5]), which are compliant with the
MPEG-2 private section format (see ISO/IEC 13818-1 [1]).
Data carousels
- The data broadcast specification for data carousels supports data broadcast services that require the periodic
transmission of data modules through DVB compliant broadcast networks. The modules are of known sizes and
may be updated, added to, or removed from the data carousel in time. Modules can be clustered into a group of
modules if required by the service. Likewise, groups can in turn be clustered into SuperGroups.
- Data broadcast according to the data carousel specification is transmitted in a DSM-CC data carousel which is
defined in MPEG-2 DSM-CC (see ISO/IEC 13818-6 [5]). the present document defines additional structures and
descriptors to be used in DVB compliant networks. The method is such that no explicit references are made to
PIDs and timing parameters enabling preparation of the content off-line.
Object carousels
- The object carousel specification has been added in order to support data broadcast services that require the
periodic broadcasting of DSM-CC User-User (U-U) Objects through DVB compliant broadcast networks,
specifically as defined by DVB Systems for Interactive Services (SIS) (see ETS 300 802 [10]). Data broadcast
according to the DVB object carousel specification is transmitted according to the DSM-CC Object Carousel and
DSM-CC Data Carousel specification which are defined in MPEG-2 DSM-CC (see ISO/IEC 13818-6 [5]).