LAUSR

In this paper, topology design, optimal routing, and gateways placement selection algorithms are proposed in Heterogeneous Cloud Radio Access Network (C-RAN) with exploiting Free Space Optical (FSO) communication. The proposed network consists of two tiers; the lower tier concerns with clustering Remote Radio Heads (RRHs) based on traffic demands. The upper tier consists of transceivers along with the Cluster Heads (CHs) and gateways. Algorithms are proposed to achieve the lowest number of edges and the highest possible throughput based on the presented optimization problem. Moreover, route optimization and gateway selection problems have been considered in two different traffic scenarios; static (maximum occupancy) or dynamic (Partial occupancy). Furthermore, a disaster recovery algorithm is proposed in case of failure of one of the nodes or edges to maintain the continuous connectivity of the network at the expense of the traffic. Our simulation results show that the number of gateways in a dynamic traffic operation is reduced by 33% in node size of 25, 36, and 42. Also, this reduction is increased to 41% if the node size increased to 49.