A Spectrum- and Energy-Efficient Scheme for Improving the Utilization of MDRU-Based Disaster Resilient Networks

The movable and deployable resource unit (MDRU)-based network provides communication services in disaster-struck areas where the lack of spectrum and energy resources is intensified due to the high demand from users and the power outages after a disaster. The MDRU-based network attempts to apply spectrum- and energy-efficient methods to provide communications services to users. However, existing works in this field only consider spectrum efficiency or energy efficiency separately, in spite of the tradeoff relationship between them. Thus, we propose a scheme to improve the utilization of both spectrum and energy resources for better system performance. The considered MDRU-based network is composed of gateways deployed in the disaster area, which can replenish their energy by using solar panels. Our proposed scheme constructs a topology based on the top k spectrum-efficient paths from each sender and applies a max flow algorithm with vertex capacities, which are the number of transmissions that each gateway can send, which is referred to as transmission capability. The transmission capability of each gateway is determined by its energy resource and distances to its neighbors. Furthermore, we show that the proposal can be used for multisender-multireceiver topologies. A new metric named spectrum-energy efficiency to measure both spectrum efficiency and energy efficiency of the network is defined. Through analyses, we prove that a value of k exists such that the spectrum-energy efficiency of a given topology is maximized. Furthermore, our simulation results show that, by dynamically selecting appropriate value of k, the proposed scheme can provide better spectrum-energy efficiency than existing approaches. Moreover, our experimental results verify the findings of our analysis.