There are huge differences between countries when it comes to broadcasting and how broadcasting networks must be built and operated. Topography, legislation, urbanization and the number of people all play a role when determining the strategy for a transfer from anaologue radio to digital radio. Why do these things matter?
Topography and geography
Mountains, bodies of water and big buildings reflect radio signals. Digital signals are strengthened through reflections, analogue signals are destroyed. The size of the country does also play an important part, so does neighboring countries.
Some governments have set a preliminary switch off date for FM, others are merely following the market, yet others are expected to decide on one certain date and ensure predictability for both broadcasters and listeners. Legislation is also relevant when it comes to how powerful the radio signals can be (laws govern maximum radiated power from transmitters).
In some countries most people live in towns and cities which require few transmitters. Other countries have a much more rural population pattern which requires more transmitters and makes it much more expensive to cover the country.
A big population increases the potential revenue base and lowers the cost per reached listener.
To cover two countries with radio signals can never be seen as two identical operations. Even the type of trees in a forest or the temperature of water affects how signals are spread and therefore also how networks have to be built in order to provide good coverage to the end users..
I have listed examples from Denmark, Norway and the UK below to show certain differences. Let's look at how many people an average transmitter reaches:
The reach of one average FM transmitter
1) Denmark: 69,356 persons
2) UK: 52,219 persons
3) Norway: 2,421 persons
The average FM transmitter in the UK does in other words reach 21 times more people than in Norway while the average FM transmitter in Denmark reaches 28 times more people. That's a difference of 2800% per transmitter.
The reach of one average DAB transmitter
1) UK: 124,700 persons
2) Denmark: 50,227 persons
3) Norway: 8,954 persons
With DAB, the difference is cut in half between the UK and Norway, but not in Denmark where they reach fewer people per DAB transmitter than what is the case with FM. The reason is that the power for a DAB transmitter can be substantially lower and still give similar results (due to the robustness of a digital signal). Even with 50% additional DAB transmitters that give the listeners 200% more radio stations, the electricity costs still go down for the Danes.
Cutting power, boosting choice
The costs for Norwegian Broadcasting Corporation (NRK) to transmit via FM is extremelly high, especially when you look at the cost per person. So much for being a radio broadcaster in the worlds most beautiful country in the world.
In Norway 23% of the population lives in small villages or even more isolated from neighbours. And the country is among the 7 biggest ones in Europe area wise. In smaller Denmark and the UK a higher percentage of the population lives in towns and cities.
The extremeties of Norway makes it natural for Norway to show the way, to be the first to switch off FM. Britain has already opened up for analogue switch off in 2015, but this depends on the willingness among Brits to get access to more radio stations and go green. Can Norway beat them to it? No shut off date for FM in Norway exists quite yet, but to get one in place and start telling people about the obvious benefits would greatly help the budgets of broadcasters and give them more money for programming. Plus provide many more radio stations to everyone, in a more environmentally friendly manner as NRK will only need half the electricity for many more radio stations when FM is history and DAB reaches everyone.
Money will certainly also be saved also in Britain where we are looking at estimations that show electricity being cut to less that a third. Denmark is smaller and easier to cover, but even there estimated savings on electricity will amount to 20%. And if or when we see a successfull switch off in Norway, that may help pave the way for others.
Why cover everyone?
Of course, there is no need to cover everyone in a country. Those living on rural farms or islands have preety much chosen to do so themselves and should face the consequences. Shouldn't they? Well, commercial broadcasters rarely reach everyone in a country with their signals. But public service broadcasters have an obligation through the way they are financed (the license fees) to cover everyone. The BBC, DR and NRK are all license funded public service broadcasters.
I have used information made available online by the public service broadcasters in Denmark, Norway and the UK to examplify differences. The following estimates are based on my own counts, understanding of available information and calculations:
Area: 43,094 sq. km.
Persons per sq. km.: 128
Urbanization: 87% of population
Terrain: Flat, some hills, no mountains.
DR via FM (4 radio stations)
Persons per transmitter on average: 69,936
Estimated power consumption per year: 3.3 million kWh
Persons per kWh per year: 1.7
DR via DAB (18 radio stations)
Transmitters: 110 (2 multiplexes)
Persons per transmitter on average: 50,227
Estimated power consumption per year: 2.6 million kWh
Persons per kWh per year: 2.1
Area: 323,802 sq. km.
Persons per sq. km.: 15
Urbanization: 77% of population
Terrain: Huge amounts of rugged mountains broken by valleys and fjords, small scattered plains.
NRK via FM (1-5 radio stations)
People per transmitter on average: 2,421
Estimated power consumption per year: 19 million kWh
Persons per kWh per year: 0.26
NRK via DAB (13 radio stations)
People per transmitter on average: 8,954
Estimated power consumption per year: 9.5 million kWh
Persons per kWh per year: 0.52
Area: 243,610 sq. km.
Persons per sq. km.: 256
Urbanization: 90% of population
Terrain: Predominantly flat with rugged hills, some low mountains.
BBC via FM (1-5 radio stations)
People per transmitter on average: 52,219
Estmated kWh per year: 29 million kWh
Persons per kWh per year: 2.15
BBC via DAB (11 radio stations)
People per transmitter on average: 124,700
Estmated kWh per year: 8 million kWh
Persons per kWh per year: 7.8
CIA - The World Factbook, IDAG, World DMB, transmitter maps from Denmark, Norway and the UK.