The problem: Radio broadcasting falls into two camps.

  1. ‘Big stick’ broadcasting: where I hire a big stick, and broadcast out of it across thousands or millions of people. Some people won’t like what I have to offer. Many won’t listen. Yet, there is a finite radio spectrum, so even if I broadcast a special channel for choral music fans, that’ll stop people who want to broadcast heavy garage punk instead. It’s hugely wasteful and limiting in terms of choice.

  2. Internet broadcasting: where I broadcast via the internet and pay for people to listen to my station in terms of bandwidth costs. Multicast is a long way off - so I get penalised for success… the more people that listen, the more bandwidth I have to pay for. And, for mobile broadcasting, this option gets even more expensive as consumers have to pay for the bandwidth they use, too. It’s expensive and impractical.

There has to be a better way. And there is. I call it mobDAB.

The solution: On demand, micro-broadcasting.

Every cellphone base station has a mobDAB transmitter on it, capable of broadcasting twelve stations out a list of hundreds available: local, national and world stations are all available on this unit. If you want to listen to any radio station in the world, you can.

You want to listen to Radio 4, so you turn on your mobDAB receiver and choose “Radio 4” from the menu. Using the inbuilt mobile in your mobDAB receiver, this says to the base station “Hoy. I want to listen to Radio 4”. The base station goes “Oooh, okay, I’m broadcasting it on channel 3 then”. Your mobDAB tuner tunes in to channel 3 and gets Radio 4 as normal. Every few minutes, your mobDAB receiver lets the base station know you’re still listening.

A second person wants to listen to Radio 4, and turns on his mobDAB receiver. “Can I listen to Radio 4 please?”, says the receiver to the base station. “Certainly”, says the base station, “I’m already broadcasting it on channel 3”. So his mobDAB tuner listens in to Radio 4 as well. This could continue until thousands of people were listening off the same channel.

A third person wants to listen to KGBH Boston - and the base station obligingly starts broadcasting it on channel 7. Etc, etc, etc.

If there are more than twelve different stations being broadcast, the base station is full. You can listen to another station - perhaps even queue your request - but you can’t listen until there’s a spare channel. This might sound bad - but cellphone base stations cover a small area - typically a square mile or less in most built-up areas. If you’re covering a predominantly Pakistani area, for example, it’s likely that a lot of the channels on that base station will be Pakistani. If you’re in a Jewish area, you’ll have a lot of Jewish stations. If a fairly upper class area, it might be a lot of Radio 3 and

mobDAB would offer far more choice, and a far more efficient use of the radio spectrum than ever seen before. It would tailor its available channels, automatically, to the listening habits of the micro-community near its base. It is cheap to run in terms of bandwidth, and ensures that nothing is ‘wasted’: if less than the twelve channels are being broadcast, the transmitter even switches itself off!

mobDAB is a winning idea. Who pays for the installation, of course, is a different issue: but perhaps it’s possible with 3G?