Dynamic Transmission Power Allocation for Cache-enabled Multi-hop Networks

In this paper, we focus on a cache-enabled multi-hop network, where the unmanned aerial vehicles (UAVs), the user equipment (UEs), or both can serve as relays to deliver contents to individual users from a ground base station (GBS). We formulate a power optimization problem with the objective to minimize the sum content delivery delay. We show the optimization problem is non-convex, thus, we propose a novel heuristic algorithm to allocate the power to individual contents at individual hops in multi-hop scenario. The proposed heuristic algorithm iteratively re-allocates the transmission power among the contents at the same transmitting node. To reduce the number of iteration, the proposed algorithm enables parallel power re-allocation for multiple content pairs and dynamic adaptation of power re-allocation steps, thereby enabling faster convergence of the algorithm. We demonstrate that our proposal reduces the average content delivery duration by up to 31.8 % compared to state-of-the-art works. At the same time, proposal is suitable for real systems due to a very fast convergence.