A method for synchronizing media reproduction across heterogeneous networks is presented. The networks include end-to-end IP broadband and narrowband simulcast networks that contain broadband and narrowband devices associated with a common communications group. A controller in the networks determines delay times for reproduction of a media stream across devices in the networks and establishes the longest delay time. The longest delay time is used to calculate appropriate transmission and reproduction timestamps to permit the devices to reproduce the provided media stream in synchronization. Narrowband base stations repeat the media stream at the time specified by a transmission timestamp, and broadband end devices reproduce the media stream at the time specified by a reproduction timestamp. By synchronizing the presentation time, the devices present the media at substantially the same time and are granted fair rights to communicate with one another.