|Vintage QSL from Radio Minsk (Gayle Van Horn Collection)|
Wednesday, August 05, 2015
The Russian authorities have returned to the idea of digital radio
So do not run the digital broadcasting, the Russian authorities are ready to change its format. Instead of previously planned standard DRM are invited to return to the standard DAB, but in a more modern modification - DAB +. It has proved to CNews report of the Moscow State University of Communications and Informatics on the outcome of the test digital broadcasting standard DAB +. Testing was conducted by the federal state enterprise "Russian Television and Radio Broadcasting Network" (RTRS) in relation to last year issued a resolution of the State Commission for Radio Frequencies (SCR).
On the digitization of broadcasting in Russian thinking at the same time broadcasting digitalization - at the end of the 1990s. Then the State Committee was going to be used for European digital broadcasting standard DAB (Digital Audio Broadcasting), designed for VHF (VHF). By 2010, planned to cover the DAB-broadcasting all over the country, but work in this area has not been carried out.
The federal program of digitalization of TV and radio broadcasting was adopted only in 2009, and by the time it was decided to use a different standard of digital radio - DRM (Digital Radio Mondiale), designed for long, medium and short waves.
However, in the implementation of DRM was also not carried out any work. Now it offers a return to the RTRS standard DAB, but his more recent modifications - DAB +. Standards of DAB / DAB + broadcast intended for the so-called third radio frequency - 174 - 230 MHz. Now that Russia is busy TV range, but after disconnecting analog TV broadcasting, he should be released.
DAB + standard is different from the more modern use of DAB audio codec - HE-ACC v2 instead of MPEG 1 layer 2, thereby improving the quality of broadcasting and improve error correction. DAB + allows for a single frequency to broadcast up to 16 radio stations in stereo quality (DAB standard allows up to 10 radio stations broadcasting on the same frequency).
The current standard DAB / DAB + implemented in 21 countries: most are the countries of Europe as well as Hong Kong, South Korea and Australia. Another 15 countries are testing this standard. At the end of 2014 the subscribers numbered 89 million digital radio DAB / DAB + a year their number has quadrupled. Testing was carried out DAB + broadcast RTRS in Moscow Ostankino television tower, was used for the test broadcast radio "Mayak". Check signal during several hiking routes - in areas Khoroshevo-Mnevniki and Kuntsevo and Tagansky district - showed quite sure reception except for a few areas.
Inside the apartment buildings also saw positive reception. But inside stores located in these areas - "Pyaterochka", "Dixie", "Sportmaster", "Rainbow", "The Seventh Continent" and others. Signal could catch just next to the windows. In the basement fairs and shops, as well as pedestrian crossings reception absent. Testing in cars at the site of the Moscow "Crocus Expo" to Riga highway showed that reception was carried out with varying degrees of success. Outside of Moscow - in the village Putilkovo Krasnogorsk district of Moscow region - reception was only possible in areas of low-rise buildings. In urban areas, including in shops and shopping centers, the reception was absent.
After processing the test results, it was found that to ensure a comfortable in-car signal reception DAB / DAB + (in the mode of broadcasting up to 16 radio stereo quality) indicator intensity of 63 dB V / m for the metropolis and 49 dB V / m in rural areas. Featured reception inside buildings, these figures should be 74 dB V / m and 54 dB V / m, respectively.
Earlier studies have found that the broadcast signal standard DRM (one radio program in stereo quality) measure the field strength of a metropolis at 72 dB V / m (can receive 50% of the buildings) and 34 dB V / m in rural areas.
For analog FM broadcast (one radio program in monokachestve) measure the field strength of 70 dB V / m for megacities and 48 dB V / m in rural areas. Provided a radio broadcast in stereo, as the figures are 74 dB V / m and 54 dB V / m, respectively.
Thus, for broadcast in a rural lowest transmit power required for standard DRM. In conditions of megacities requirements transmitter power DAB / DAB + are similar to those that apply to DRM transmitters and analog broadcasting. But a strong advantage is the ability to DAB + broadcasting organization once 16 radio stations on the same frequency. The cost of a transmitter for DAB + 2.5 kW is $ 120 thousand. The rest of the equipment needed to run the broadcast - multiplexer DAB, encoder DAB +, modulator, power amplifier 250 W, channel filter, the antenna - will cost a total of $ 50 thousand.
To organize the same analog broadcast transmitter needs to be worth $ 50 thousand (with a capacity of 10 kW). It's cheaper than a transmitter for DAB +. However, when you consider that a single transmitter transmits DAB + stations to 16, then from an economic point of organization of digital broadcasting DAB + is more profitable than analog broadcasting "from scratch".
If the analogue broadcasting has already been deployed, the transition to DAB + can save only on energy costs. Estimated savings of 1.375 million rubles. per year, ie the cost of only one transmitter will pay for only four years.
But in the case of the release of the third range of the analog TV to use their existing RTRS transmitter and antenna. Then the cost of the remaining equipment needed to start broadcasting standard DAB +, will be 30 thousand euros, and by reducing the cost of electricity it can be back in just 1.5 years.
The draft decision SCR (available to the CNews) was assumed for the consideration of the report, select the frequency band 174 - 320 MHz for the broadcasting standard DAB +. However, the final decision of the Commission said that the SCR only took note of the report and requested the RTRS continue work in this area. In the course of RTRS consider DAB + not comment.
The creator of the Russian standard digital broadcasting "Rāvis" Alexander Dvorkovich said Russia's use of standard DAB + impractical. "The advantage of this standard is sufficiently large fleet of subscriber equipment - said Dvorkovich. - However, used DAB + frequency range is not intended for the Russian sound broadcasting, while the FM band (66-77 MHz) "idle." Moreover, economic efficiency broadcasting so high, compared with the FM and FM (88 - 108 MHz), the frequency is not apparent". Finally, DAB + standard involves the use of a large multiplex programs, which is opposed by the majority of broadcasters, which is one and two programs. "In order to fill a multiplex programs need to combine several broadcasters, and it is inconvenient for them, and sometimes unacceptable - explains Dvorkovich. - At the same time they get a service area, which is not convenient for everybody". (cnews.ru via OnAir.ru in RUS-DX No. 830, Jul 26)
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