Springer Science+Business Media
It is shown that the throughput capacity of wireless ad hoc networks using Omni-directional antennas is significantly decreased with the increased number of nodes. One major reason lies in the interference caused by using Omni-directional antennas, which just broadcast radio signal in all directions. Thus, a communication with multiple short-ranged hops is suggested in such networks to avoid interference and improve the throughput. However, the multi-hop transmission can also significantly increase the end-to-end delay. In this paper, they investigate the throughput improvement and the delay reduction by using directional antennas in wireless ad hoc networks.