This paper presents a novel wireless projecting and cooperating approach named FreeSpeech based on Ad Hoc network, which makes conference exchange more convenient and ubiquitous. All attendees can access this system by their laptops or other mobile computing devices all around the conference venue and make the projections of their presentations without connecting to the projector physically. Moreover, they can make cooperative display simultaneously with others. FreeSpeech takes a mixed
Virtual Networking Computing
(VNC) C/S mode based on some improvements on the traditional ones. A novel IP multicast-based transfer and control mechanism is presented to make large numbers of attendees obtain the wall screen contents by their laptops locally without aggravating the overhead of bandwidth remarkably. An efficient remote screen synchronization method is employed to transfer screens of some attendees to the projector-connected computer, which also can save the consumed bandwidth significantly. All above methods use the limited wireless bandwidth more efficiently. Performance evaluation shows that this approach can work perfectly for ubiquitous conference occasions.