Abstract
In this paper, the problem of user association and sub-channel allocation in integrated satellite-drone networks (ISDNs) is studied. In this model, drone base stations (DBSs) provide downlink connectivity, supplementally, to ground users whose demand cannot be satisfied by terrestrial small cell base station (SBSs). Meanwhile, a satellite system is used to satisfy the increased demand for backhaul resources stemming from DBSs and SBSs. In this case, one must jointly consider resource allocation over satellite-DBS/SBS backhaul links, terrestrial backhaul links, and DBS/SBS-user radio access links as well as user association with DBSs and SBSs. This joint backhaul and radio user association and sub-channel allocation problem is modeled using a competitive market setting in which all of the communication links are modeled as consumers while the user association outcomes and the wireless sub-channels are modeled as goods. In this competitive market, consumers seek to exchange goods to maximize their profits, in terms of users' data rates. The sum rate of communication links, defined as the social welfare in the competitive market, is maximized in a sequential manner. An optimal satellite frequency sub-channel allocation scheme is first proposed given the sub-channel allocation and user association scheme at DBSs and SBSs. Then, the problems of sub-channel allocation and user association at DBSs and SBSs are solved using a Hungarian-based solution, such that the sum rate of all communication links are maximized. Simulation results show that, the proposed algorithm can find a Walrasian equilibrium allocation scheme, at which the spectrum resources in the market is fully used, upon convergence. Meanwhile, the proposed algorithm can yield over two-fold gains in terms of the number of downlink service links with 35 Mbps rate and 3:4 times gains in the number of backhaul links with 1 Gbps rate.
