Multiobjective Optimization for Integrated Ground-Air-Space Networks: Current Research and Future Challenges

With space and aerial platforms deployed at different altitudes, integrated ground-air-space (IGAS) networks will\ud have multiple vertical layers, hence forming a three-dimensional\ud (3D) structure. These 3D IGAS networks integrating both aerial\ud and space platforms into terrestrial communications constitute a\ud promising architecture for building fully connected global next\ud generation networks (NGNs). This article presents a systematic\ud treatment of 3D networks from the perspective of multi-objective\ud optimization. Given the inherent features of these 3D links,\ud the resultant 3D networks are more complex than conventional\ud terrestrial networks. To design 3D networks accommodating the\ud diverse performance requirements of NGNs, this article provides\ud a multi-objective optimization framework for 3D networks in\ud terms of their diverse performance metrics. We conclude by\ud identifying a range of future research challenges in designing\ud 3D networks and by highlighting a suite of potential solutions.