In 2010 research work on making and carrying out full-scale tests of essentially new Russian audiovisual information system RAVIS model for VHF frequency range instead of analog FM broadcasting systems was complete, the domestic standard GOST R 54309-2011 “Audiovisual information system of real time RAVIS. Processes of formation of personnel structure, channel coding and modulation for the system of digital terrestrial narrow-band broadcasting in VHF band. Technical conditions.” was developed and approved. This system was based on RF patent №2441321 for "mobile narrowband digital multimedia broadcasting method" with priority of 26.07.2010.
When making the RAVIS model and domestic standard, the following important technical requirements were set:
- making of a digital audio-visual broadcasting system in the VHF band (65.8-74 and 87.5-108 MHz), in which FM radio broadcasting is conducted in Russia;
- using international standards ETSI, ISO, ITU;
- higher spectral efficiency compared to analog FM broadcasting systems;
- increased service reliability compared to analogue broadcasting, especially in mobile reception;
- ability to develop low-cost receivers;
- support for single frequency networks;
- using the achievements of video and audio coding systems of a new level in the quality of image and sound reproduction within the reception of information in moving transport;
- meeting the ever-increasing demand for frequency assignments for communication systems without revising frequency distributions;
- broadcasting several high-quality audio programs, including support for stereo and multi-channel sound, broadcasting video with acceptable clarity with stereo sound;
- use of a data transfer protocol that allows introducing new multimedia services;
- opportunity to use diversity transmission and diversity reception;
- full-scale tests of the RAVIS system model in urban conditions of densely built-up areas in Moscow, as well as in mountainous terrain in Sochi were carried out; the RAVIS system receiver was placed in a moving car, while the reception was carried out using a conventional whip antenna located on the roof of the car. Photos are attached.
РThe test results of the RAVIS system in Sochi are similar to the test results in Moscow.
In fact, we can talk about the complete success of the RAVIS system model testing and its readiness for further development, R&D work and the introduction of appropriate equipment in production and operation. GRCC Decision No. 10-08-05 of 23.08.2010 specifies that "the results of the researches confirmed the possibility of the RAVIS system use which allows to increase considerably efficiency of frequency spectrum use and to carry out:
- multi-channel audio broadcasting;
- video programs broadcasting for the mobile consumers and television broadcasting in sparsely populated areas;
- making of multimedia systems;
- making of single-frequency mobile broadcasting networks along highways and railways;
- making of public warning systems;
- integration in Russia into the global telecommunications system.
In accordance with the GRCC decision of October 2015, experimental broadcasting zones were organized in Kazan and Izhevsk, and in 2017-2018, experimental tests of the RAVIS system were conducted.