It is thought the venture, which now has the backing of all of the UK's major terrestrial broadcasters as well as ISP BT, will allow users to watch catch-up TV services such as the BBC iPlayer over an internet connection provided by a set-top box.
It is also expected that there will also be no restriction on the ISPs that can offer broadband access through the set-top box.
Catch-up service reviews:
Gill Pritchard, director of strategy, Channel 4, said: "IPTV is set to become the next generation of TV and if Channel 4 is to continue to enhance its importance in a fully converged world it is key to be part of driving Project Canvas".
"We believe that Project Canvas is an important development that will bring considerable benefits to all viewers, increasing the accessibility of on-demand content for everyone, not just the technologically savvy."
The BBC said it expects the venture to cost each backer £16.4m over four years.
"Internet-connectivity is going to have a transformational effect on TV. By seamlessly converging broadband and broadcast content, project canvas can help secure the future of free-to-air broadcasting and create an open platform that gives online services a route to the TV set," added Richard Halton, Project Canvas programme director.
Project Canvas still needs to approval of the BBC Trust before it can be publicly rolled out.
See also: Channel Five joins Project Canvas