Downlink Coverage Probability and Rate Analysis Based on Backhaul-Access Pair in Moving Networks

Moving networks with mobile small base stations (MSBSs) provide ubiquitous and continuous services for users in beyond fifth-generation (B5G) system. MSBSs are mounted on the vehicle, receive/transmit signals from/to macro base stations (MBS) via wireless backhaul, and provide 5G connectivity to user equipments (UE). In this paper, we develop a stochastic geometry-based analytical framework for analyzing the downlink coverage probability and rate coverage of moving networks, where the service distance distribution of a typical UE (an arbitrarily selected receiving UE) associated with an MSBS is characterized as a joint distribution of backhaul-access pair, and its closed-form expression is derived at various MSBS movement locations. By utilizing this characteristic, we further derive the coverage probability based on the Laplace transform of the interference power distribution. Furthermore, the downlink rate coverage for the typical UE is derived using backhaul-access pair and Voronoi mosaics to characterize the mean and particular load on the serving MBS and MSBS, respectively. Our simulation results show that there exists an optimal ratio of wireless backhaul bandwidth allocation maximizing the rate coverage for given network parameters such as the density and selection bias of MSBSs. Additionally, we also observe that there are saturating values of the network parameters in the process of improving the network metrics without the need to be blindly increased.