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Digital Radio Mondiale & All India Radio.

By. Joseph Martin C.J      Sources . www.drm.org & other online Sources



                2009 saw All India Radio embracing the Digital Radio transmission, thus beginning a new era in the history of Radio Broadcasting in India. In India, after a series of test & trials for last 2 years, proving again its undoubted leadership, All India Radio launched its first Digital Radio Transmission (DRM Service) on 16.01.2009 from its old grand High Power Transmitter complex situated in khampur at  Delhi. Existing short wave transmitter at khampur has been modified for DRM broadcasting and radiating at freq. 6100 kHz from 14.30 to 17.30 on100 KW power. The primary expected coverage area of this system is 800 km.The qualities of DRM signals were superb. Very near to fm quality. The improvement over AM was immediately noticeable. The only limitation is the Coast of the receiver which is 10000 to 15000 in the market. But it is going to come down significantly as the drm  services becomes popular.Thease receivres are equipped with attractive features like recording to SD card ,epg  programmed reception & recording, Analog & reception ,Display of programme related issues etc.Apart from enhancing the audio quality drm has the capacity to transmit  programme related data


            For  Digital Radio transmission All India radio has adopted Digital Radio Mondiale  (DRM ) as the digital successor to Medium Wave transmission.   Digital Radio Mondiale (abbreviated  DRM; Mondiale  being French for "worldwide) is the universal, openly standardised, digital radio broadcasting system for short-wave, medium-wave and long-wave - digital radio for the  radio frequencies below 30MHz. Digital Radio Mondiale  is also the name of the international Non-profit consortium  of 75  broadcast related organizations designing and implementing the platform  to develop a digital transmission system for the current AM broadcast band .


      The DRM  system provides a universal , non proprietary, digital transmission system designed to replace the current analogue transmissions in the  LW,MW, and SW bands . Many nations have already approved DRM as the digital  successor to Medium wave. DRM  is professively going to replace classic AM broadcasting , by using only existing band and existing infrastructure with little modification  in the transmitter. The principle of DRM is that band width is the limited element ,and computer processing power is cheap,So modern CPU intensive audio compression technique s enable more efficient use of available band width.

                         DRM has near- FM sound quality plus the ease-of-use that comes from digital transmissions. The improvement over AM is immediately noticeable. DRM can be used for a range of audio content, and has the capacity to integrate text and data. This additional content can be displayed on DRM receivers to enhance the listening experience. DRM uses the existing AM broadcast frequency bands and is designed to fit in with the existing AM broadcast band plan, based on signals of 9 kHz or10 kHz bandwidth. It also has modes requiring only 4.5 kHz or 5 kHz bandwidth, and modes that can take advantage of wider bandwidths - 18 kHz or 20 kHz - allowing DRM to operate alongside  AM transmissions in every market of the world.

                             The DRM system uses COFDM (Coded Orthogonal Frequency Division Multiplex). This means that all the data, produced from the digitally encoded audio and associated data signals, is shared out for transmission across a large number of closely spaced carriers. All of these carriers are contained within the allotted transmission channel. Time interleaving is applied in order to militate against fading. Various parameters of the OFDM and  coding can be varied to allow DRM to  operate successfully in many different propagation environments – the selection of the parameters allows transmissions  to be planned that find the best combination of transmit  power, robustness and data capacity. In addition, CELP and HVXC coders are available to provide speech-only programming at even lower data rates.

Benefits of Digital AM for Listeners


      More choice.

        The average radio today can receive some 35-40 local FM stations and a handful of Medium Wave broadcasts. DRM has the potential to bring to every radio a vast selection of new content. New programmes from the world’s  leading international broadcasters. Quality speech radio on Medium Wave, focusing on national and regional topics. And, a world of community radios keen to find a voice.


       No compromise in sound quality.

     The huge innovation that DRM brings is that Short Wave and Medium Wave broadcasts can now be heard in FM-like sound quality. And reception is excellent anywhere – in cities and in dense forests, indoors in a block of flats and outdoors while driving your car

      It is still a radio ...

          and not a computer. Which means that you don’t need an internet connection to listen nor a Wi-Fi spot to tune in. And because of this, it is truly portable and mobile. You can take a DRM radio anyplace and listen to what you want, When you want, where you want.


  A radio without boundaries..


           Because DRM is ideally suited to long range broadcasting, you can stay tuned to the same station as you cross regional and national boundaries and move from one country to the next..

    All the benefits of digital radio...

             A low cost DRM receiver will deliver all the benefits associated with modern digital radios. You have access to an Electronic Programme Guide (EPG) and you can tune in easily by frequency, station name or type of programme. In addition, the programmes come with associated text information – the name of  the station, the title of the programme or record playing etc. And, as most DRM radios can also tune in to both the analogue FM and MW bands and DAB, where available, this will be the one device you will need to listen to all your favourite radio content.

Benefits of Digital AM for Prasar Bharati

         For broadcasters of all kinds, DRM is a great advantage.  For major international broadcasters, like Prasar Bharati it is the obvious replacement for traditional Short Wave transmitters. The existing transmitter systems can   be used, because of its in band, on channel technology it can operate in hybrid mode simulating both analog signal and digital signal. the investment in digital technology only 10%-20 %. Of a new transmitter power consumption will go down by 20 –40 %, less electro smog and pollution etc


        DRM allows direct access to millions of listeners in excellent sound quality, without the hindrance of having to negotiate a way past the gatekeepers and at an excellent cost/reach ratio.

        For specialised international broadcasting - for example, for external services of   All India Radio – DRM is, so to speak, an answer to a prayer. It allows them to reach the parts other systems cannot reach, for a fraction of the cost.  DRM on Medium Wave is perfect for broadcasters aiming for a national audience, especially in countries like India covering a sizeable geographical area. In France, where the regulatory authorities have already approved DRM as the digital successor to Medium Wave,  two transmitters will cover the entire country. In large countries, like Russia or India, DRM may be the only means to achieve seamless national coverage in the digital era – and it will certainly be the most cost efficient.

              DRM is also the ideal solution for regional Medium Wave coverage, on its own and, of course, DRM is simply perfect for broadcasters planning to roll out new, additional digital services and generate new revenue streams without compromising their existing content offer.


A cost efficient solution

            DRM is a cost efficient solution to Prasar Bhrati. Medium Wave transmitters can be converted to DRM mode at low cost and the useful life of the equipment  significantly prolonged, both from a technical and a financial point of view. The scope of the capital investment required is also manageable because just a few transmitters can achieve excellent coverage over very extensive territories. Unlike other systems of digital audio broadcasting, DRM does not require a large network of transmitters or a complicated lattice of repeaters to do the job.

             Transmission revenue costs are no higher to those of analogue Short and Medium Wave broadcasts and offer excellent value  for money given the wide area coverage and the superior sound quality. DRM has been developed to operate alongside other digital radio technologies and in the field of receivers the future surely lies not with radio sets that are compatible just with one technical standard but with integrated hybrid tests that work in the analogue  bands and can also decode DAB/DMB signals. The integration of DRM capability into these hybrid chipsets can be achieved at marginal cost, adding very little to the cost of the radio to the consumer.

Digital Radio has a great  future

             While television is forging ahead with digital conversion and many countries have already set analogue switchover dates in the first half of the next decade, radio is entering the digital era at a much slower pace. At the same time, the triumph of the iPod  and the expanding capacities of mobile phones, handheld and laptops are leading people to question whether radio has a digital  future at all. Well, radio does have a digital future, because of its immediacy and its portability and DRM will be an integral part of that future. For radio to move into the digital world in step with other platforms, sound needs to be in a format that these other platforms can understand – and the DRM standard provides that. The day that your DRM radio will be talking to your mp3 player and your iPod is here. DRM is currently best suited to the AM bands while DAB has been promoted as an alternative to FM. More importantly, perhaps, in the short term, it is relatively straightforward and cost effective to integrate DRM








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