DVB-SI is an acronym for Digital Video Broadcasting-Service information, this regulation is defined in the document of the ETSI EN 300468, which was established in October 1995 and amended several times. There is a separate technical writing, also from the ETSI, which increases the information contained in the document that defines, that letter is the ETR 211. DVB-SI is the standard data transmission in the digital television broadcasts. This information system is a service to provide the user navigation through DVB environment, a platform for digital television.
Introduction
DVB-SI operates on MPEG-2 as a complement to Information Specific Program (ISP). This service provides users and decoder ease of navigating through the chain of services offered. The process begins when MPEG-2 PSI (Specific Information Program) provides a key to IRD (Integrated Decoder Receiver) or Set-top boxes to be set automatically. So DVB-SI adds information that allows the IRD DVB show tune certain services or programs of interest agendas. Because of the complexity that mean for users to navigate through the new digital TV services, DVB-SI provides the necessary elements to develop the Electronic Program Guide (EPG).
Being very large quantity of data formats for the EPG was conducted by the EACEM a specification with the most suitable data formats contained in [ETS 300707], as well as a guidance document that facilitates the interpretation of the specification is content [ETR 288]. DVB-SI consists mainly of four types of tables of information service, as well as a set of additional tables, which make possible its use. In contrast with the tables MPEG-ISPs that provide only information Transport Stream (TS) in which they are located, however tables DVB-SI also can provide information services and other events carried by TS and even transmitted by TSs by other networks. This allows switching between different IRD TSs so undetectable by the user.
Tables of information services
Main Tables
Chart Information Network (Network Information Table (ILS)): it presents the information needed for tuning channels of a service provider. The IRD uses this information during its cargo. Besides these tables are used to signal a change of tune. Table Description of Service (Service Description Table (SDT)): list the parameters associated with each service, in particular with the multiplex MPEG.
Table Event Information (Event Information Table (EIT)): transmitting information by bringing together all the events that occur and that will occur on the multiplex MPEG. It also contains information on transportation and other current flows that can receive the IRD. Table with the time and date (Table Time and Date (DTT)): used to update the internal clock of IRD.
Additional Tables
There Association Bouquet (Table Bouquet Association (BAT)): it could be an aid to the IRD to show the services available in a manner understandable to the user.
Tables State Implementation (Running Status Table (RST)): used to update the execution of a program. Sections of the state of implementation are sent once abroad, and later, when there is any change. This is not happening with the rest of SI tables, which are sent continuously.
Tables Fill (Stuffing Table (ST)): therefore can be used to replace any sub table that is mistaken as to complete a table SI. Table of discontinuity of information (Discontinuity Information Table (ITL)): is used at the point of transition where the information is discontinuous, for example when there is a change of network. Table selection information (Selection Information Table (SIT)): A summary of all important information is in the TS.
Repetition Frequency tables
We must distinguish two types of DVB broadcasts, cable (DVB-C) and satellite (DVB-S) and terrestrial DVB-T. For the first two systems it is assumed that the channel bandwidth is sufficient to transport all the necessary information. These are the frequencies of repetition: All sections of the NIT must be transmitted at least every 10 s, including those who travel through other avenues of dissemination, if any. All sections of the BAT must be transmitted at least every 10 s, if present. All sections of the TDS of current multiplexing must be transmitted every 2 s, as a minimum. All sections of the TDS other TS is required to transmit at least every 10 seconds. All sections of the EIT of current events and subsequent current TS be transmitted every 2 seconds, at least. All sections of the EIT of events TS be transmitted every 10 seconds, at least, if they exist. All sections of the programming of the EIT of the first 8 days must pass at least every 10 seconds, if they exist. All sections of the programming of the EIT of days beyond the eighth should be transmitted every 30 seconds (including those of the other TS), if they exist.
The DTT be transmitted every 30 seconds, at least. Regarding emissions of digital terrestrial television, the bandwidth is very limited to the amount of information that must be aired, and defines the following periods of repetition, bearing in mind that the tables NIT, BAT, SDT and DTT have to meet the same minimum as for cable and satellite. All sections of the EIT of current events and subsequent current TS be transmitted every 2 seconds, at least. All sections of the TS events from other TS be transmitted every 20 seconds, at least, if they exist. All sections of the programming of the current day EIT should be transmitted at least every 10 seconds, if any. All sections of the programming of the current day EIT another TS be transmitted every 30 seconds. All sections of the programming of EIT TS should be transmitted at least every 30 s, if they exist. All sections of the programming of other TS TS is required to transmit at least every 30 s, if they exist.
Localization program.
The automatic tuning IRD according to the service selected.
The Application Programming Interface (API) is the system provides connectivity between software applications and hardware, making a simile comparison with a PC, it would be the operating system of IRD.
The Electronic Program Guide (EPG): software application created by content providers, to facilitate the filing of the services they offer and to help turn the election of the viewer.
Conditional Access (CA).
Specific applications [edit] Information Services (IS) DVB has been designed to work on a wide range of applications. These are some of the most prominent:
NVOD: the concept of Near Video on Demand (NVOD) is defined as the repetition of a program throughout the day, but moved in different moments of time.
Mosaic: consists of a series of small images of different programs on the same image. These small images are encoded at the source so that each occupies a particular area in the overall picture.
