Distributed retransmission method using neighbor terminals for ad hoc networks

We propose a novel distributed retransmission control method for ad hoc networks. Since ad hoc networks are based on wireless communication to transmit data among terminals, radio interference or obstacles often cause link failures and packet loss. In conventional ad hoc routing protocols, a source terminal must discover and reconstruct a new transmission route when link failures or multiple packet losses are observed on the current route. Such route discovery schemes generally increase network traffic. Various retransmission control mechanisms and multipath routing protocols have been proposed to overcome this problem. In the conventional method, however, the terminal that retransmits the lost packets should be located in the neighborhood of the destination terminal. In other words, only the last hop on the route is retransmittable. Moreover, although multipath routing mechanisms can increase transmission success rate, the terminal overhead increases owing to transmission of extra data stream on the route. The proposed method cooperatively uses neighboring terminals of the route to enable retransmission from any terminal on the route. The effectiveness of our method is demonstrated by computer simulation.