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DRM Digital Radio Comes of Age

Thanks to its adoption in India, the DRM broadcasting standard continues to advance

NEW DELHI — At this moment, public broadcaster All India Radio is operating 35 medium-wave (AM) and two shortwave radio transmitters using the Digital Radio Mondiale broadcasting standard, in an ambitious bid to rollout pristine digital radio service to the nation.

A DRM radio-equipped Hyundai car on display at the 2017 BES Expo held in New Delhi in February.
Credit: The DRM

“Both of AIR’s shortwave transmitters are broadcasting in pure DRM mode,” said Yogendra Pal, former additional director general of AIR and head of the Indian chapter of the DRM Consortium, the global organization promoting the DRM standard. “Out of 35 medium-wave transmitters, two are working in pure DRM carrying two audio services each in digital, and all the other 33 transmitters are working in simulcast mode. As of March 7, AIR has issued orders to operate 25 of the medium-wave DRM transmitters in pure DRM for one hour daily.”

AIR’s ultimate goal is to convert all of its medium-wave transmitters to DRM-only service. This will occur once the penetration of DRM receivers in India is sufficient to justify shutting down analog medium-wave transmissions. The original DRM-30 data-based transmission standard works in the bands below 30 MHz. The newer DRM+ standard goes above 30 MHz and covers Bands I, II and III up to 240 MHz.

For the DRM Consortium, whose members include many of the world’s major radio broadcasters and equipment manufacturers, India’s adoption of DRM justifies the group’s years of hard slogging. Although shortwave broadcasters such as the BBC, Radio France International and Vatican Radio are currently making limited DRM broadcasts to their audiences, AIR is the first major broadcaster to embrace DRM as an operational standard. In doing so, India has validated DRM as a digital radio format; one to be taken as seriously as Europe’s DAB/DAB+ and North America’s HD Radio.

From left to right, Ruxandra Obreja, DRM chair; George Ross, TWR, Guam; and Alexander Zink, Fraunhofer IIS/vice chair DRM, showing DRM reception on mobile devices and the Titus II software-defined radio receiver.
Credit: The DRM

“The DRM rollout in India is quite spectacular,” said DRM Chair Ruxandra Obreja. “The first phase of the project was the installation of DRM-capable transmitters. Now we are entering a second phase where better sound, value-added nonaudio services, and receiver manufacturing are being seriously pushed and promoted.”

DRM’s success in gaining a foothold in India seems likely to be repeated in nations such as Pakistan and Brazil, at least if the digital radio plans of broadcasters in these two countries come to fruition. What follows below is a closer look at India’s DRM progress to date, plus a glance at Pakistan and Brazil’s DRM ambitions.


With an estimated 1.2 billion citizens currently being served by AIR’s radio broadcasts, the decision to adopt DRM as the country’s digital radio standard was made after the broadcaster’s deliberation and testing of DRM and DAB transmission systems.

The AV-DR-1401 DRM/AM/FM radio receiver, built by India’s Avion Electronics, is the first Indian-built DRM radio.
Credit: Avion Electronics

“AIR selected DRM based on this technology’s ability to deliver clear, full-range digital audio on medium wave, FM and the interference-ridden shortwave bands,” said Pal, the retired AIR executive who helped spearhead India’s DRM rollout.

Given the popularity of AIR’s global SW services — “available in more than 108 countries in 27 languages in analog,” Pal said — plus AIR’s “vast network of over 140 analog medium-wave transmitters giving service to over 98 percent population of the country,” selecting the DRM digital radio standard made good sense for India’s public broadcaster.

The fact that DRM-enabled medium-wave transmitters can also simulcast in analog medium wave cinched the deal. “Until DRM digital receivers are available to a sizable population, analog medium-wave services can continue along with digital service from the same transmitter,” Pal said. “No additional frequency spectrum was required, existing infrastructure such as transmission lines and antennas masts did not have to be replaced — and even the existing transmitters could be converted to digital at a nominal cost.”

This said, AIR did buy a number of new DRM-capable transmitters from Nautel, which was great news for the Canadian transmitter manufacturer.

The All India Radio transmission tower in Mangalore, Karnataka is one of many covering the nation with DRM signals.
Credit: Gopala Krishna A via Wiki Commons

“Nautel is proud to have supplied 11 100 kW NX100, 10 200 kW NX200, and six 300 kW NX300 DRM-enabled medium-wave AM transmitters to AIR; comprising the world’s largest digital radio deployment to date,” said Chuck Kelly, Nautel’s Asia/Pacific Regional sales manager. “Nautel has [since] received a follow-on order from AIR for another four NX100s, and two NX200s.”

Of course, successfully deploying a specific digital radio broadcast technology requires the existence of compatible digital radio receivers. The widespread availability of DAB/DAB+ receivers in Europe has been central to the medium’s current success in this region.

Conversely, a lack of DAB receivers doomed Canada’s DAB rollout in the late 1990s. This lack of receivers resulted in the DAB transmitters that were simulcasting the country’s AM/FM services in Canada’s major cities to eventually go dark. Currently, some Canadian private broadcasters are rolling out U.S.-designed HD Radio transmitters into service on a trial basis.

In India, the push is on to get affordable, domestically made DRM receivers into the marketplace, and the hands of Indian radio listeners. “One Indian domestic manufacturer has already developed a standalone DRM receiver,” said Pal.

Prasar Bharti All India Radio & Doordarshan Broadcasting Centre in Neemuch, Madhya Pradesh.
Credit: Rahultalreja11 via Wiki Commons

“Some automobile manufacturers have also incorporated DRM reception facility in their built-in audio systems. Our domestic receiver industry sees a very good opportunity in meeting domestic demand as well as making DRM radios for export.”

The current price of India’s domestically made first DRM/MW(AM)/FM receiver, the Avion Electronics AV-DR-1401, is US$189. Compared to the cost of conventional MW/FM radios, this is quite expensive in a country where 29.8 percent of the population is below the poverty line, according to the CIA World Factbook.

“The price of standalone DRM digital receivers is certainly a concern at present,” Pal acknowledged, “but I am sure that prices will go down very fast with demand; as we have seen in the deployment of any new technologies in many other fields. The eventual availability of a DRM reception facility in cellular phones will further boost the popularity of DRM digital services.”

PBC’s Senior Broadcast Engineer Ghulam Mujaddid setting up the GatesAir FM transmitter along with the RF Mondiale DRM+ equipment for lab testing in Islamabad, Pakistan.
Credit: Pakistan Broadcasting Corp.


Unlike India, Pakistan’s public-operated Pakistan Broadcasting Corp. (Radio Pakistan) is interested in possibly deploying DRM+ first on FM, and then eventually medium wave. In fact, the country has already begun DRM+ field tests in the FM band, at its Islamabad facilities.

PBC’s decision to focus on FM digital radio first is due to the country’s large and growing urban population, and the fact that this technologically progressive audience is also more affluent than its rural counterpart.

“The literacy rate is much higher in the metro cities, as well as its buying power of new digital DRM receivers compared to rural areas,” said Ghulam Mujaddid. He is PBC’s senior broadcast engineer, a member of PBC’s DRM Steering Committee, and an observer member of the DRM Consortium’s International DRM Steering Board. “It is also worth mentioning that the upfront equipment cost required for the transition in DRM+ for FM transmitters is much lower as compared to DRM-30 for AM transmitters,” said Mujaddid.

A screenshot of PBC’s DRM+ professional receiver showing a live DRM+ test transmission in Islamabad, Pakistan.
Credit: Pakistan Broadcasting Corp..

Pakistan’s current broadcast spectrum allocation explains why the country chose DRM over DAB. “DAB uses Band III (174 MHz to 240 MHz), which is already occupied by the Pakistan Television terrestrial network and some other departments,” Mujaddid said. “DRM+ works in Band II (88 MHz to 108 MHz), which is already the established band for FM broadcast. So it is quite easy and smooth for us to use the same FM band while transitioning to the DRM+ standard.”

The fact that India is rolling out DRM also influenced Pakistan’s choice of DRM over DAB. Broadcast compatibility with your next door neighbor counts.

At present, PBC has 20 FM transmitters that are fully capable of DRM+ standard broadcasting across the country, and plans to buy 20 more DRM+-capable transmitters in the 2017–2018 financial year. PBC already has 10 kW, 100 kW and 400 kW MW/AM transmitters that are fully capable of supporting DRM-30 standard broadcasts.

A screenshot of PBC’s GatesAir DRM+ FM transmitter showing the live DRM+ transmission in Islamabad.
Credit: Pakistan Broadcasting Corp.

The fact that PBC can operate its existing and new transmitters in dual DRM/analog mode was a big selling point in DRM’s favor. “In contrast, DAB transmitters do not support analog and only work in the digital mode,” said Mujaddid. “So we can’t run both modes from a single DAB transmitter.” Cost also gave DRM the edge over DAB: “FM transmitters, which normally transmit analog signals, can easily be converted to DRM+ by just adding a small piece of hardware to it,” he explained.

Although PBC is eager to start rolling out DRM+ and eventually DRM-30 as well, it is no rush to shut down FM and medium wave. “There is no specific date for the rollout to be completed; it all depends on the factors and challenges we have already discussed,” said Mujaddid. This said, “PBC is determined to rollout digital radio standard in the country to provide efficient and better programs to the people of Pakistan.”


Since 2012, Brazil has had two reasons for wanting to deploy DRM. First, the country is forward-minded when it comes to digital broadcasting. Second, when the national government “made a public call for digital radio standards to present themselves to be tested in Brazil, DAB did not attend,” said Marcelo Goedert, owner of the Brazilian audio equipment firm Audio Fidelity Produções Ltda, and the DRM Consortium’s Brazilian representative. “So it was never officially considered for Brazil.” Add the fact that Brazil is a very large country — “any digital radio solutions have to consider long distance transmissions via medium wave and shortwave,” said Goedert, “and DRM was the right choice.”

Unfortunately, ongoing economic and political unrest is delaying Brazil’s adoption of DRM as the country’s digital radio standard. In the interim, DRM field tests are underway. Specifically, DRM-30 signals have been test-broadcast by Empresa Brasil de Comunicação, Brazil’s public broadcaster, on 9.740 kHz shortwave, since the end of October, 2016.

“We are using a low-power 150 W DRM transmitter installed at the Rodeador Site in Brasília, the capital in the center of the country,” Goedert said. “The aim of this test is to assess the behavior of the equipment, signal quality and system stability. Because of the low power, there were not any high expectations of large coverage but, despite all this, the signal has been detected all around Brazil — and there were some intermittent signals received in New Zealand.” A new trial will start in April 2017 with a 1 kW transmitter, from the same site.

As for equipment, Brazil has a domestic transmitter manufacturer, BT-Broadcast Transmitters that makes DRM transmitters to sell locally and to other countries. “Receivers for the test are coming from India,” noted Goedert. “Since we don’t have digital radio yet, no company has started manufacturing in the country yet.”

“The main challenge for Brazil is the governmental delay in establishing parameters for digital radio,” Goedert concluded. “The other challenge is the diversity of Brazilian radio. We have around 10,000 radio stations divided into private, public, educational and communitarian; all with different interests and priorities. So it is very hard to find an agreement on radio policies and technical standards.”


Collectively, these three countries and their interest in DRM underscores how this digital radio technology has finally found its place on the world stage. No longer is DRM an engineer’s pet project: It is now a credible broadcast standard.

Having achieved this result, the DRM Consortium’s task now is to capitalize on DRM’s momentum and use it to attract other nations to the standard.

“Wider take-up and use of DRM remains the goal,” said Obreja. “This goes in parallel with increasing the volumes of sold or integrated receivers that should establish digital radio as the norm and bring radio where it belongs: as the ultimate integrator and ubiquitous glue for all new and old digital platforms.”

James Careless reports on the industry for Radio World from Ottawa, Ontario.