UAVs as Relay Nodes: Positioning Method for Heterogeneous Wireless Networks

In scenarios where Relay Nodes (RNs) need to be deployed to restore the connectivity of a partitioned wireless network, a positioning method limiting the number of RNs required is necessary. Optimally, the method must take into account the differences of transmission ranges between the different nodes - or the heterogeneity in range of the network. In particular, Unmanned Aerial Vehicles (UAVs) are considered to be great candidates as RNs with their high mobility and ability to be quickly deployed. However, their radio parameters will be different from the Initial Nodes (INs) of the network and there will be a diversity in propagation channel. Plus, even the network might be heterogeneous. With a mobile initial network, the placement method also have to be stable in terms of RN positions and number with respect to IN displacements. This paper introduces an approach to modify an effective RN placement algorithm for homogeneous networks to create a new algorithm capable of managing heterogeneity in the networks. The new algorithm is the Barycenter-focused Relay Positioning for Heterogeneous Wireless Networks (BRHEN) algorithm. In addition to lower the number of RNs compared to the initial algorithm, it also enhances its stability with respect to small IN displacements.