Q&A - Digital or FM

Questions and Answers
Answers to the 27 questions below have been prepared in consultation with experts in the field. Do you find as a reader that an answer is incorrect in any way; the editor will appreciate your feedback. The same applies if you cannot find an answer to your questions. Updates will be ongoing.

1. ”DAB” stands for digital radio? 

Not really. DAB (Digital Audio Broadcasting) is the brand name of one of several technical systems for distributing digital sound broadcasting wirelessly. The other systems now recognized by the International Telecommunications Union are DRM (Digital Radio Mondiale), HD Radio and ISDB-T. Since 2013 China has developed its own digital radio standard CDR. Now on the agenda is also DVB-T2 Lite which is a spin-off from the digital terrestrial television system DVB-T2.  Adding to this there is digital radio transmitted via satellites and increasingly worldwide via Internet (fixed or mobile broadband).


The key characteristics of FM, HD Radio, CDR, DRM+, DAB+ and DVB-T2 Lite (ISDB-T excluded)
2. What is the plus in DAB + and DRM + indicating?
DAB+ is an upgraded version of DAB and provides better capacity for more channels. However, it is the same model with multiplexer (multiplexes). DRM + is an expanded version of DRM, originally comprising frequencies below 30 MHz (short / medium / long wave). DRM+ covers higher frequencies (Band I to III) up to 300 Mhz. Band II is the current FM band and band III is today used for DAB.  More at "Radio Bands" page.

3. Are many countries making a transition to digital radio?
Today, you will find FM radio in 200 countries. It is a world standard. No country has so far set a date to ”switch-off” FM. So far, in a limited number of countries, in Western Europe and Australia, DAB systems are operational, but still FM networks are running as before.

4. Is the European Union pushing for DAB? And the EBU? 

The European Commission has announced that it will not take any decision on a "European standard", but prefer that the so-called multi-platform development i.e. a single receiving apparatus to receive multiple systems such as FM, DAB / DAB +, DRM30 and DRM +.

There are no official European institutions pushing for digital wireless radio. The European Broadcasting Union – the interest organization of the public service companies - is lobbying for the DAB system and a closure of the FM band. However, in February 2013 the EBU issued recommendations that when DAB coverage is not possible, to use DRM/DRM+ for digital radio broadcasting in the frequency bands currently used for analogue radio broadcasting (AM and FM).

5. Will any country “switch off” FM?
There are no an international plans for completely closing the FM band, nor on national basis in any country. (See also item 7 below).

Denmark and Norway want the public service and the commercial radio networks to switch to DAB, but keeping FM for local radio stations. Finland is instead using the VHF Band III (174-230 MHz) for television. 
Finland definitely rejected DAB 2007 and will instead use the this DVB-T network also for digital radio.

In Sweden the former Socialdemocratic government dismissed DAB already in 2005. In June 2015 the present Socialdemocratic-Green party coalition government again rejected any plans to replace FM with DAB+ due to massive negative opinion including a consultation round and dismissal by the National Audit.

This decision was confirmed without opposition by the Parliament in February 2016. Read more.

Among other countries which recently decided not to switch-off FM are Australia, Ireland and South Africa. 

6. Will DAB radio ultimately succeed as a global standard?
It is very unlikely. The main factors are 
a)  FM is an well established world standard in more than 200 countries.
b)  Online radio is swiftly expanding globally. It is forecast that every man and woman in the world will possess a smartphone 2025. This will be the major radio and music listening device - not a standalone radio receiver.
c)  DAB is introduced by decree not by market demand.  

Today there are few countries where significant DAB listening figures are presented. In Denmark, Norway, Switzerland, the UK and Australia have 10-25 % listening on weekly basis.  But in some countries - even with DAB networks with national coverage as Germany and the Netherlands - there are just a few percent listening.

EBU and The lobby organization WorldDAB (former WorldDMB) is trying to sell another story to you by not mentioning the absence of major actors - the listeners.

7. Can the FM band be "closed" by a government?
According to the EU directive on electronic communications a Member State cannot prohibit the use of a frequency range internationally allocated for a specific use. A  government will not be able to ban the use of Band II for sound broadcasting in any EU country. Thus, the wide spread rumours that a country has decided, "to shut down FM" is untrue. But politicians can force the publicly funded radio public service to only transmit DAB, forcing listeners to follow and hopefully commercial radio and community radio will come along.

8. Are FM transmitters out of date and need to be replaced?
In Sweden the FM network is robust and modern, can easily be upgraded if needed. Today there is a wide range of modern and effective FM transmitter even in budget class for around 3,500 euro for community radio. Norway's FM network for public service is outdated and needs to be upgraded or replaced by another system.

9. Is there space for more stations on the FM band? 

There is plenty of spectrum for smaller radio stations across in most countries except the major metropolitan areas. The FM band is not optimal utilized, but this can improved by replanning the frequencies. This is costly, but a significant less costly method than replace FM with DAB.

10. Should we say no to new technologies? 

There is no rule that says that new technology always means improvement. DAB can be an improvement, but only for major broadcasters and not necessarily for listeners. After 20 years, DAB has not succeeded on the consumer market as a "new technology" (In fact it was invented in Germany already 1985). It can be seen a solution in search of a problem - instead of a solution solving a problem.

11. Terrestrial television has been digitized and why not the same for terrestrial radio?
A transition to terrestrial analogue television to digital (DTT) has been completed in most Western European countries. Before terrestrial analogue television was the common way to distribute television. However, other platforms have gradually taken over. For example in Sweden, only 24% of households receive television terrestrially, while two-thirds of households watch television mainly via cable television, and also via satellite and broadband (IPTV).

11. Was DAB was developed later than digital terrestrial television? 

The digital systems (DAB, respectively. DVB-T), which was developed in the 1990’s for radio and TV respectively although DAB was invented already 1985 in Germany. The systems are based on the similar structure of multiplexes with capacity for more channels. The UK and Sweden started DAB broadcasting 1995 quite many years prior to digital television was introduced. DAB in Sweden was broadcast as a pilot project, which officially ceased 2002, but is still running.

There was a significant demand for more TV channels than for more radio. Also significantly more bandwidth was required for television. Since then the demand for more stations, which may have existed in the 90s, declined significantly since digital radio via the Internet today offers a diversity that terrestrial platform cannot match. (See also item 18 below)

13. Is the European standard DRM a better option than HD Radio?
DRM, part of the Digital Radio Mondiale, is developed in France, Germany and Sweden. It is considered a better choice than HD Radio, both technically and economically. HD Radio is also proprietary which means that a broadcaster has to pay a user license to the company iBiquity Digital Corporation that owns the technology. There are royalties paid for DRM but only by the transmitter manufactures.

As an open system DRM offers the possibility for everybody to develop new applications including open source transmitter software with DAB and DRM. It will be possible for small-scale local radio to build own, low-cost transmitters.

HD Radio (IBOC) operates with a total bandwidth of 400 kHz, which is not compatible with the existing channel raster of Band II (the FM-band) in Europe and many other parts of the world. DRM+ operates within a bandwidth of 100 kHz, which makes it natural choice for a smooth transition from analogue to digital on the FM band. It would allow 1-4 radio programmes within the same spectrum currently occupied by one FM programme.

14. Which digital radio system cover the complete sound broadcasting bands? 

DRM is the most complete system. Both HD Radio and DRM can be used on frequencies today used by most radio stations in the world; AM (medium wave) and FM. But DRM30 can also be used on shortwave and DRM+ in Band III (used for DAB). DAB can only be used in Band III.

15. DAB has more efficient coding technique than DRM +?
No, both DAB + and DRM + uses the basic encoding technology, HE-AAC (AAC). 
DRM is now (2013) the first broadcast standard to have adopted xHE-AAC making DRM a digital option closely aligned to the mobile platform options.

16. Is DAB utilizing the frequency spectrum better?
DAB has a particular spectrum (Band III), which is on the higher frequencies than FM band (Band II), but DRM + is more frequency efficient with a bandwidth of 100 kHz compared with the DAB multiplex 1.500 kHz.

17. Is it space enough on the Internet for all radio stations? More than a third of the world's population is connected to the Internet. Online, there is an ongoing increase of television and various film services. The need for bandwidth is constantly increasing and capacity expansion takes place all the time. For example, some residential properties in European cities offer access to up to 1000 Mb bandwidth. In comparison with television radio requires insignificant amount of bandwidth. Thus, this is not a reason to increase the wireless space for sound broadcasting. 



2020 is said to be the year when LTE Broadcast will be in regular use for mobile broadband. It is a developed version of Multimedia Broadcast Multicast Service (eMBMS) today used in 4G networks to transmit data intense traffic including video to a mass audience - from unicast to broadcast mode.

In the telecom industry many believe that in combination with 5G LTE Broadcast in the future will replace radio and TV terrestrial broadcasting because the capacity for audio and video will be almost unlimited.

18. Has DAB better sound quality than FM?

DAB can only reach the same quality level as FM if the bandwidth is not lower than 160 kb/s. However, the operators will squeeze 12-16 channels into one multiplex 1500 kB/s thus narrowing bandwidth to 32-128 kB/s. A research report on this was presented in Sweden in November 2013. Read more: DAB Radio Sound Quality Inferior to FM

On the Internet it is no problem for streaming radio to use a bandwitdh of 320 kB/s. This is used by some classical music and jazz radio stations as BBC3 HD.

19. Has DAB a better geographical reach than FM? 

Schema: Niels Dreijer & Jens Christian Seeberg (Teracom Denmark)

No, the higher the frequency the smaller the range. DAB operates in Band III (174-240 MHz), while the FM broadcast in Band II (87.5-108 MHz).  Smaller the range = more the amount of transmitters.

You will in principle need 64 DAB-transmitters for 16 FM-transmitter which in turn are required to reach the same coverage as one medium wave (AM) transmitter (See illustration -> )


British media authority Ofcom believes that it is very difficult and expensive to roll out DAB in Scotland and Wales, due to geographical reasons. As DAB fails to cover the entire population FM or DRM + must supplement.Together with being on a higher frequency DAB has difficulties to reach indoors and other difficult reception points because of this.

20. Will digital radio save energy?
A digital transmitter is said to need less power than an analogue FM transmitter. However,
if you replace a larger FM Transmitter with DAB + must also expect to deploy slave transmitter or "gap-fillers" to maintain the same coverage as before (see point 18 above). New FM transmitters are much more energy efficient as they have very limited energy loss. A modern FM transmitter draws 70% less electricity than with an older type of analogue FM. A modern FM transmitter can probably be considered as energy efficient as a DAB transmitter.


But this does not apply to the receiver where the energy consumption is higher. So far, mobile phone manufacturers have not put DAB in their phones as this will draw 8-9 times more energy than a built-in FM tuner. A new multichip released 2013 might enable lower power consumption for digital radio.


21. Why no DAB radios in mobile/smartphones?
On most mobile phones you can receive on-line more than 40.000 radio channels world-wide. Also there are often a built in FM receiver (except in iPhones).  Up till now there has also been a problem of high power consumption for digital radio (see point 19 above). 

Yet, a global market for DAB radio is still too far off in order to stimulate
 mobile and smartphone manufacturers to include DAB receiving capabilities. In March 2016 the first mobile phone with DAB radio was launched by LG - the LG Stylus 2 smartphone. However, the mobile operators are not interested to subside mobile phones with DAB+ as there is not a sustainable business model. As they prefer online radio listening the market outlook for DAB in mobile phones is not bright.

There are an estimated 6 billion FM-receivers in the world, while today there are only 30 million DAB-receivers (two-thirds in the U.K.). 

22. Are the listeners asking for more channels?
A typical DAB + network can provide 40-60 national radio channels, but there are no market studies or research confirming such a demand for wireless radio today. Internet radio was not on the map when DAB was developed in the 90's. The same applies to the alternative methods of music distribution today as iPod, iTunes, Spotify, Wimp and the like. More than 40,000 digital radio stations are available on the Internet.

23. Will DAB “free-to-air” sound broadcasting give better free access than Internet radio? To receive web radio you usually have to be a subscriber to an Internet service provider while receiving on-air radio is “free”. However, mobile broadband operators in some countries (the US, Finland and Sweden for example) recently opened for unlimited Internet access. You will not pay any extra fees for listening to streamed music as Spotify or radio online.


Public service radio is financed by household licensing or taxes. Commercial radio is paid by the consumers via the advertisement costs on products and services. In contrary to public service and commercial radio community radio stations in most countries will have to fund with own means for any on-air broadcasting.

“Net neutrality” is an issue regarding Internet access. However, also for a multiplex system as DAB/DAB+ a third party will always be the operator of the transmission system and thus a gatekeeper being able to control access and set prices.

24. Will DAB be less costly to use?
DAB + is cost effective if all the channels are exploited, but there are significant additional costs to administer and operate a program production for new channels (studio technology, personnel and royalties for music, etc).

There are no studies indicating any need for more public service channels. Nor has the commercial radio interests been able to prove that more channels can increase profits. On the contrary more channel available will probably strengthen commercial oligopolies by increasing control of the wireless space. Small operators will not have the resources to join the complex DAB-structure.

25. Why is DAB detrimental for local radio and community radio? 

The Swedish public service commission has in its report noted that DAB is not appropriate for local radio and believes that FM cannot be turned off until a solution for community radio is found. Similar conclusions have been reached in Denmark, Norway and the UK. 

The DAB "Small scale solution for local broadcasters" does not solve the prime problem of how to run a local multiplex efficiently with only one or two programs, the remainder of the mux being empty. Besides large metropolitan areas there will not be any resources to run more than one community radio channel per village or town.

26. Why can I not "tune in" for a radio station on DAB?
The DAB system is built on distribution structure based on the model of digital terrestrial television (DVB-T) with the so-called multiplexer (multiplexes). This is a complete break with the transparent system the listeners all over the world is used to; tune in per frequency on the AM or FM band (as well as HD Radio and DRM). For DAB channels are transmitted in various so-called blocks programmed into the receiver.

27. Will a "Single Frequency Network" be possible with DAB only?
It will be also possible with DRM+ and some other digital audio radio system. SFN means that a radio station can use the same frequency for multiple transmitters simultaneously even within its coverage area. This makes it easier for the listener to find his radio station if it has transmitters in more than one place.