A study on performance improvement of ad hoc multicast by directional antenna

Multicast communication is an efficient packet dissemination method in ad hoc network. However, in ad hoc multicast communication, packet collisions due to the hidden terminal problem happen frequently because each host does not use the RTS/CTS frames that has been used in conventional unicast communication. So, wireless channel is not reserved for any multicast packet transmissions and hidden terminal problem degrades multicast communication performance. One promising way for improving hidden terminal problem is directional antenna. Because interference can be decreased by directional antenna, the hiding terminal problem can be improved. In this paper, we evaluate basic performance of multicast communication with directional antenna in ad hoc networks. Performance evaluation by computer simulation shows that throughput performance can be improved by using directional antenna because the radio wave interference decreases and the hidden terminal problem that is brought by some independent multicast sessions can be controlled.