Satellite Links Integrated in 5G SDN-enabled Backhaul Networks: An Iterative Joint Power and Flow Assignment

While recent technological advances have focused on how to provide increased data rate in 5G Radio Access Network (RAN), very few attention has been paid on how the current microwave backhaul network can handle the transport of such huge traffic flows. In this paper, we address two key aspects for the efficient adaptation of the backhaul network to the upcoming SDN-enabled 5G wireless communications. First, we consider the availability of dedicated satellite links to off-load the traffic from the terrestrial backhaul links. These satellite links operate on the non-exclusive Ka band, which is shared with the terrestrial microwave backhaul links. Second, and given the interference limited scenario, we address the power control and flow assignment of the resulting satellite terrestrial network. While most of the flow assignment works consider the link rates as fixed and given, here we provide a novel formulation which links the achievable link rates with the assigned transmission power. In particular, we propose an iterative joint power control and How assignment which takes into account the long propagation delay imposed by the satellite links. We transform the resulting non-convex problem into a Geometric Programming (GP) problem, which can be optimally solved in an efficient way. Simulation results validate and demonstrate the benefits of the proposed approach.