Elif Bozkaya, PhD Candidate:
Department of Computer Engineering, Istanbul Technical University &
Department of Computer Engineering, National Defense University Naval Academy,
supported by The Scientific and Technical Research Council of Turkey (TUBITAK)
Abstract:
Resiliency in communication networks is the maintainability of the communication functionality at acceptable levels against possible errors, environmental problems, network outage due to technological causes or malicious attacks. However, it is tremendously time-consuming to redesign the network in a versatile disaster situation considering today’s static and conservative communication network infrastructures. In disaster management; assessing the situation, taking immediate and effective precautions and proposing solutions for the optimization is only possible with a robust communication network infrastructure. Additionally, in case of base station failures, there is no infrastructure to manage the mobile traffic in today’s mobile network provider systems. In order to solve this problem, mobile data traffic should be managed adaptively.
In recent years, the disasters which were caused by climatic changes can’t be prevented. In case of a disaster/natural disaster, the most important thing is to save people’s lives. In a situation like this, the first 72 hours is crucially important to react immediately and this can only be possible with quick and effective Search and Rescue activities. On the other hand, the lack of awareness and communications will vitiate these activities. For example, after the 2011 T?hoku Earthquake in Japan, most of the base stations became out-of-service and the Internet had become available barely after 7 days. Also, the service quality of the satellite phones, which are used only for voice communications by the save and rescue teams had decreased. A similar situation was experienced in 2010 after the earthquake in Haiti and long-term communication problems arose due to damaged service provider infrastructures. In the mentioned disaster scenarios, it is not possible to meet the data demands with the limited physical resources of the infrastructure along with the damages in the existing wireless communication infrastructure. To this end, novel applications are needed in order to solve the network management problems in case of an unanticipated failure.
Today, with the increasing use of Unmanned Aerial Vehicles (UAV), many new applications are emerging in the communication sector. According to the AUVSI report (2013), direct economic impact from the UAV industry in US is about $3.6 Billions in 2018 and is expected to exceed $5 Billions by 2025. In this study, UAVs are proposed to support the communication infrastructure as a aerial base station via a central controller to solve the problems for existing network infrastructures. Thus, it is aimed to design a resilient network management mechanism conceptually at system level. The UAVs which will be located instead of the failed base stations are advantageous because they have low production and maintenance costs, they have error/damage tolerance and they can easily be controlled and located where humans have limited to reach. However, because of the physical limitations UAVs with low-capacity power supplies; they have limited flying time, limited velocity and communication range. Moreover, the majority of energy consumption in aerial networks is not spent on computing or communication, but on the power required by engines and flying airless vehicles. For all these reasons, there are various problems in the system design while trying to accomplish real-world problems and complicated duties. Therefore, in order to increase resiliency in aerial networks, a proper positioning management and a flight planning mechanism are both needed considering the relationship between drone flight characteristics and energy consumption. In this context, with the proposed original network management platform, a three-dimensional flight planning will be proposed, which locates the aerial base stations according to user density and traffic flow, taking into account the energy consumption of the entire topology. Thus, a solution will be presented in a flexible and centralized structure, which analyses the resiliency of the network in real time and is sensitive to increased mobile data traffic and dynamic topology changes.
Considering the stated reasons, firstly, optimal position planning will be performed with the minimum number of aerial base stations that will be needed for effective management of a given geographical area. After locating the aerial base stations in the appropriate positions, the location updates will be managed through a central controller by monitoring the change of user intensity over time. Then, it is planned to use the shortest path algorithms that take into account the flight characteristics and the energy consumption relationship in order to obtain an optimum flight planning for the designated locations. Thus, a UAV assisted, centralized and flexible network infrastructure that is sensitive to dynamic network topologies and minimizes the problems arising from the use of UAVs will be established and the resiliency of the system will be evaluated.
