With mobiles starting to dominate our daily lives, there is growing interest in the idea of TV on the phone.

Mobile TV has been tried before, never with much success.

There is the problem of getting decent reception while you are on the move, let alone the issue of battery life and watching programmes on a tiny screen.

The truth is, the bar has been set high. A mobile TV service has to live up to the expectations of the digital TV generation.

"The most important thing to realise about the difference between mobile TV and digital TV is that with digital TV at home, you've got an unlimited power supply and a large aerial on the roof of the building, both of which are quite handy," said Mark Squires of Nokia.

Screen technology itself has advanced in the last few years, making the viewing experience much more enjoyable.

But TV screens are notoriously power hungry. In mobile versions the backlight and speaker will need to be on throughout the programme.

Clear picture

However, a method called time-slicing means that at least the receiver is not on all the time.

"Time-slicing is a way of making the device's battery last a lot longer because it isn't running all the time," explained Mr Squires.

"What's actually happening is that the programme it's receiving is being sent to it in very intense bursts of data, and between those bursts it allows the device to completely shut down, apart, obviously, from the screen and the sound.

"To the user it looks like the programme is being received constantly, all the time, but in fact the device is in a sleep state for the majority of the time."

Receiving the programme in short, high-speed bursts means that the signal is received a few seconds before it is needed, and that buffering means that the device can also cope with short breaks in reception. So if you go under a bridge, you will not lose the picture.

Costly service

Korea and Japan are way ahead of the game and have been testing several methods of reception for a couple of years.

The existing Korean 3G network is fast enough to stream live TV. It is basically broadband TV on your mobile.

"I first watched TV on my mobile phone when I went fishing," said Noh Eun Kyung, a mobile TV user.

"I had missed an episode of my favourite TV drama so I began watching it using my phone.

"The TV function is fun and convenient but also very expensive. I only watched about 45 minutes and it cost me about $50."

Cost, it seems, will be an important factor in mobile TV's success.

Rival technologies

It is generally agreed that content is also an issue as it will simply not be enough to rebroadcast the hundreds of existing channels to mobiles.

"We are developing specific content for mobile portable devices," said Steve Turner of Philips Semiconductors.

"Our expectations with the mobile environment is that you will want a quick fix; it won't be plain old TV, it'll be high priority content, whatever your personal profile is.

"It could be sports, could be music, could be anything, but it's something that you would probably not want to wait for."

In Asia, the race for the best mobile TV coverage is on. SK Telecom will soon launch a rival to the 3G service, broadcasting mobile TV by satellite.

And because consistency has never featured highly in technology circles, a third method is on its way.

In Europe, trials in Berlin and Helsinki are using existing terrestrial TV masts to broadcast compressed signals to handsets with additional receivers.

Now broadcasters are thinking about making the right kind of programmes and making sure people can afford to watch them.

Mobile TV is on its way, but it will probably be some time before television really breaks out of its box in the living room.