Digital Terrestrial Television, often abbreviated as digital terrestrial, is the television represented in digital form. From a technical point of view the television signal is enclosed in an electrical signal and as such can be represented in analog form or in digital form.
Projects with this TAG (4)
New DVB technology to serve satellite customers and to feed terrestrial transmitters
Today, the satellite distribution of DVB-T2 multiplexes to terrestrial transmitters located throughout the territory requires dedicated transponders for the transport of the relevant T2-MI (Modulator Interface) streams, which are not directly accessible also for direct-to-home reception by standard satellite receivers. This causes duplication of the needed satellite bandwidth, with the associated costs. To overcome this problem, DVB (Digital Video Broadcasting) has activated a new ad-hoc group, named TM-T-JSI, with the purpose of defining an optimized way to transport DVB-T/T2 multiplexes from a national head-end to the terrestrial transmitters, while allowing at the same time direct reception via DVB-S/S2 commercial satellite receivers.
Laboratory evaluation of the Demetra system for the distribution of time / frequency references via geostationary satellite
In October 2016, at the Laboratory of Rai CRIT, it was carried out a series of tests on the demonstrator for time synchronization and frequency alternative to GNSS (Global Navigation Satellite System), developed by Antares S.c.ar.l under the European Demeter project, in collaboration with INRIM.
The tests have allowed us to evaluate the behavior of the developed system, especially in reference to the specific needs for synchronization of a network of DTT transmitters in single frequency (SFN).
DVB-T2: single frequency network in Aosta Valley
The Research Center in co-operation with Rai Way has launched in Aosta Valley on UHF channel 53 a second DVB-T2 transmitter located in Salirod-Saint Vincent that, along with the transmitter Gerdaz-Aosta, installed in 2012, allowed to set up a DVB-T2 a small regional single frequency network test bed. This field trial has allowed us to experience the typical issues associated with a SFN: synchronization of transmitters, assessment of the areas of overlapping coverage, delays inserted to avoid static interference zones etc
DVB-T2 lite in Aosta Valley
A successful field trials
The Research Center, after experimenting in the laboratory the first prototypes of DVB-T2 lite, activated in Aosta Valley a single frequency network on UHF channel 53 in order to test the potential offered by the new system . The scheme chosen for the testing involves the use of “mixed” system: the T2 signal is split into two sub frames, one compatible with the standard T2 base, the other T2 lite, optimized respectively for fixed and mobile reception . The four transmitters of Gerdaz, Salirod, Arpy and Courtil radiate a bouquet consists of three HD programs for the T2 base and from one to three services oriented to mobile reception for the T2 lite.