The European Union is spending 14m euros (£10.5m) to create a standard way to send TV via the net.
An additional 5m euros (£3.7m) is being contributed to the project by 21 other partners including the BBC and the European Broadcasting Union.
The project will create a peer-to-peer system that can pipe programmes to set-top boxes and home TV sets.
It will be based on the BitTorrent technology many people already use to share movies and music.
Dubbed P2P Next, the four-year research project will try to build a system that can stand alongside the other ways that broadcasters currently get programmes to viewers.
"For the broadcasters the incentive is to take their distribution mechanism beyond terrestrial, satellite and cable," said project co-ordinator Jari Ahola, from the VTT technical research centre in Finland.
"They can use the internet as a distribution platform for very low cost," he said.
The finished system would be able to handle stored content for download and streamed content sent from live programmes such as football matches or other big ticket events.
Mr Ahola said peer-to-peer was crucial because, without it, broadcasters trying to serve large audiences would likely be overwhelmed as the numbers of those watching TV via the net grew.
Peer-to-peer systems have no central host that hands out content, such as TV shows, to viewers. Instead all the machines downloading a show make parts of it available to all the others that want it.
In this way, the load is distributed across the network.
However, he added, the finished system would also have to be able to handle broadcast-type events that can be restricted to particular audiences.
"There will be certain streams within an operator's network that will be sent only once and won't be for everyone," he said. "The geographic limitations will support the existing way of doing it."
Mr Ahola said the project aimed to have some parts of the system available by August 2008. A more complete test version should be finished within 16 months that can pipe programmes to set-top boxes so people can watch on their TV set rather than a PC.
The BBC already uses some peer-to-peer technology to underpin the iPlayer - its on-demand TV system.
P2P Next will build on the Tribler technology under development at the Delft University of Technology. Built in to this are tools that viewers can use to communicate with others that enjoy a particular programme or genre.