Abstract: Multicasting of compressed video streams over wireless networks demands significantly different approaches to error control than those used in wired networks, due to high packet loss rate. This paper describes an experimental study of a proxy service to enhance interactive MPEG-1 video streams when multicast across wireless local area networks. The architecture and operation of the proxy service are presented, followed by results of a performance study conducted on a mobile computing testbed. The main contribution of the paper is to show that a combination of forward and backward error control is effective when applied to video streams for mobile collaborating users.