3-D Dynamic Location Problem of Unmanned Aerial Vehicle Base Stations in Next Generation Wireless Communication Networks

Abstract
Facility location problems have been facing a new challenge with growing interest in unmanned aerial vehicles (UAVs) in different industries. Not only does the additional vertical dimension of UAVs increase the complexity of classical 2-D location problems, but also new coverage functions require researchers to develop new approaches to reflect real-world cases. One of the novel areas in which UAVs have been used as mobile base stations is airborne wireless communication networks, where a new tier has been added to the existing terrestrial telecommunication infrastructure. In this talk, an overview on how to integrate UAVs into wireless networks is presented, and a dynamic wireless communication network with a single UAV Base Station (UAV-BS) and multiple users who demand different service levels for different time intervals is explained.Two new formulations to determine the trajectory of the UAV-BS for a finite time horizon to maximize the total coverage are developed. In particular, a mixed-integer non-linear programming (MINLP) formulation, which is non-convex in nature, is first developed. Then, a Lagrangean Decomposition (LD) algorithm is applied to exploit this formulation. Due to high complexity of the problem, the LD algorithm is still unable to find optimal solutions to large-scale problems. Therefore, a Continuum Approximation (CA) model is developed for more challenging problems. The CA approach is shown to be promising in terms of both solution time and accuracy. The numerical study shows that the CA model can be a remedy to build efficient initial solutions for exact solution algorithms.

Short Bio
Cihan Tuğrul Çiçek is a PhD. candidate in the Department of Industrial Engineering at TOBB University of Economics and Technology. He received his BS degree from the same department in 2010, and MSc. degrees from the Department of Operations Research at Middle East Technical University (METU) and the Department of Facilities Management at University College London (UCL) in 2014. His MSc. and PhD. studies was funded under TÜBİTAK National Graduate Scholarship and The Union of Chambers of Turkey (TOBB) Foreign Studies Scholarship programmes. Before joining METU as a research assistant in 2017, he worked as junior project engineer, senior project engineer and head of operations and projects at TOBB. He visited the Department of Industrial Engineering and Operations Research Department at University of California Berkeley as a Fulbright scholar from September, 2018 to June, 2019. His research interests are non-convex optimization, facility location problems and online learning algorithms with a focus on designing wireless communication networks with unmanned aerial vehicles, which are expected to be used in the next generation cellular communication systems.

Venue

Friday, August 2, 2019, at 14.00

Rectorship Building, Güvercinlik Hall