GroundStation Based SoftwareDefined LEO Satellite Networks Low Earth Orbit (LEO) satellite networks play an indispensable role in global communications. To cope with the dynamic nature of the LEO networks, a flexible management architecture that can provide lowlatency configuration and routing services is desired. Recent advances of Software Defined Networks (SDN) inspire researches using geostationary satellites, GEO, as the controllers to build the SDN solutions for LEO satellite networks. However, GEObased solutions inevitably face the bottleneck problem because all the routing requests have to be processed and forwarded by a limited number of GEO satellites. In this paper, we propose HTCA, a Hierarchical Terrestrial Controllers Architecture based on SDN that reuses the ground stations instead of dedicated GEO satellites to establish a more scalable control plane. But the limited coverage of a ground station brings about design challenges for consistent network management and seamless routing service. HTCA adopts an online network view integration method to support flexible and consistent management. A loadaware routing method is also designed for HTCA to provide seamless and lowlatency routing service. The experiment results demonstrate that HTCA can achieve agile configuration and reduce the instruction update time by 86.87%, compared with the GEObased solution.

SDNenabled Deployment and Path Planning of Aerial Base Stations Abstract   Aerial Base Stations (ABSs) play a central role in mission critical environments due to the fast deployment, flexible reconfiguration, low cost. In this manner, through the controllable ABSs that are directed to the disaster region, users can continuously remain connected with ABSs. However, ABS deployment and path planning face several key challenges to provide ondemand communication and enable xe2x80x9dQuality of Experience (QoE)guaranteed service to the users. For example, energy consumption, maximizing the number of covered users and scheduling the ABSxe2x80x99s operations are important issues that need to be considered. Thus, this paper jointly presents a SDNenabled solution to efficiently deploy ABSs which maximizes the covered users and communication quality, and provides a path planning strategy which decreases the energy consumption. Our simulation is managed with SITL (Software In The Loop) simulator, which allows to create and test drones without a real vehicle using C compiler and we confirm the improvement in terms of connectivity and energy consumption when compared to a recent stateoftheart approach.