Directional Antenna-Based Routing Protocol With Low Detection Probability in Airborne Networks

This article proposes a directional antenna-based routing scheme for airborne networks with noncooperative eavesdroppers. The metric of route selection is to maximize the path availability time and lower the risk of communication exposure to the eavesdropper. First, based on the motion pattern of the noncooperative eavesdropper, we introduce the concept of beam lifetime. The beam lifetime is defined as the duration from the current time to when the noncooperative eavesdropper perceives the beam signal. Furthermore, we introduce the concept of path lifetime to indicate the minimum beam lifetime along the routing path. Each forwarding node (FN) records the beam lifetime in the beam table. The proposed routing protocol uses both the beam table and the routing table to establish and maintain routing paths. Unlike traditional routing schemes that apply the same path for forward and backward transmission, the proposed routing protocol uses asymmetric paths for forward/backward transmission to fully exploit the benefit of directional antennas and guarantee maximal path lifetime. Computer simulations show that the routing protocol can avoid frequent route re- establishment of conventional routing schemes.