Method and device for IP multicast over a broadcast channel

A method of and apparatus for providing an Internet Protocol multicast service wherein multicast data is transmitted through multicast routers (8) to user stations (9) over a digital broadcast channel (especially DVB-T) together with digital broadcast signals, at least if a request has been received from a user station (9) for the multicast data,. The transmission of the multicast data by a multicast router is conditional upon the reception of a request for said multicast data from that multicast router by a plurality of the user stations (9). The number of requests from the user stations (9) has to be greater than a threshold number, which is a function of the available bandwidth for multicast transmission over the broadcast channel. Information concerning the requests for the multicast data by the user stations (9) is unavailable to the other user stations (9).